| Title: | Causal network analysis methods |
|---|---|
| Description: | Causal network analysis methods for regulator prediction and network reconstruction from genome scale data. |
| Authors: | Glyn Bradley, Steven Barrett, Chirag Mistry, Mark Pipe, David Wille, David Riley, Bhushan Bonde, Peter Woollard |
| Maintainer: | Glyn Bradley <[email protected]>, Steven Barrett <[email protected]> |
| License: | GPL (>= 2) |
| Version: | 1.37.0 |
| Built: | 2024-06-30 04:43:01 UTC |
| Source: | https://github.com/bioc/CausalR |
Causal network analysis methods for regulator prediction and network reconstruction from genome scale data.
The most important functions are:
CreateCCG: read a computational causal graph from a .sif file
ReadExperimentalData: read a experimental data from a .txt file
MakePredictions: make causal reasoning predictions from a CCG
ScoreHypothesis: score causal reasoning predictions
CalculateSignificance: calculate statisitical significance of a result
RankTheHypotheses: compare different possible regulatory hypotheses on a single CCG
runSCANR: reduce false positives by selecting common hypotheses across pathlengths
WriteExplainedNodesToSifFile: reconstruct hypothesis specific regulatory network
Glyn Bradley, Steven J. Barrett, Chirag Mistry, Mark Pipe, David Riley, David Wille, Bhushan Bonde, Peter Woollard
"CausalR - extracting mechanistic sense from genome scale data", Bradley, G. and Barrett, S.J., Application note, Bioinformatics (submitted)
"Causal reasoning on biological networks: interpreting transcriptional changes", Chindelevitch et al., Bioinformatics 28 1114 (2012). doi:10.1093/bioinformatics/bts090
"Assessing statistical significance in causal graphs", Chindelevitch et al., BMC Bioinformatics 13 35 (2012). doi:10.1186/1471-2105-13-35
Adds the IDs as a vertex property to the vertices in the network. Used when creating sub-networks where the new nodes will retain the IDs from their original network
AddIDsToVertices(network)AddIDsToVertices(network)
network |
the network to which the IDs are to be added |
network with IDs added
Adds weight information to the edges of given network (1 for activation and -1 for inhibition)
AddWeightsToEdges(network, tableOfInteractions)AddWeightsToEdges(network, tableOfInteractions)
network |
an igraph constructed from the original .sif file |
tableOfInteractions |
a column of the corresponding .sif file indicating the direction of activation/interaction |
an augmented network
Returns the number of up- and down-regulated genes in the experimental data
AnalyseExperimentalData(experimentalData)AnalyseExperimentalData(experimentalData)
experimentalData |
a dataframe containing a list of genes with corresponding direction of change (1 or -1) |
up and down regulation statistics for the experimental data
Taking the list of predictions from a particular hypothesis, counts the number of positive and negative predictions in the list and the number of 0's (from numPredictions).
AnalysePredictionsList(predictionsList, numPredictions)AnalysePredictionsList(predictionsList, numPredictions)
predictionsList |
list of predictions |
numPredictions |
number of predictions |
prediction statistics
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) predictions <- MakePredictions('NodeA', +1, ccg, 2) AnalysePredictionsList(predictions,8)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) predictions <- MakePredictions('NodeA', +1, ccg, 2) AnalysePredictionsList(predictions,8)
Calculate a enrichment p-value for a given hypothesis by comparing the corresponding predicted and observed gene changes
CalculateEnrichmentPValue(predictions, results)CalculateEnrichmentPValue(predictions, results)
predictions |
predictions of changes from the CCG for a particular hypothesis |
results |
gene changes observed in the experimental data |
an enrichment p-value
predictions <- matrix(c(1,2,3,1,1,-1), ncol = 2) results<- matrix(c(1,2,3,4,1,1,-1,1), ncol = 2) CalculateEnrichmentPValue(predictions, results)predictions <- matrix(c(1,2,3,1,1,-1), ncol = 2) results<- matrix(c(1,2,3,4,1,1,-1,1), ncol = 2) CalculateEnrichmentPValue(predictions, results)
Calculates the p-value of a score given the hypothesis score and the distribution table, using either the quartic or the (faster) cubic algorithm
CalculateSignificance(hypothesisScore, predictionListStats, experimentalResultStats, epsilon = 1e-05, useCubicAlgorithm = TRUE, use1bAlgorithm = TRUE)CalculateSignificance(hypothesisScore, predictionListStats, experimentalResultStats, epsilon = 1e-05, useCubicAlgorithm = TRUE, use1bAlgorithm = TRUE)
hypothesisScore |
score for a particular hypothesis |
predictionListStats |
numbers of predicted up-regulated, predicted down-regulated and ambiguous predictions predicted by the algorithm |
experimentalResultStats |
numbers of up-regulated, down-regulated and not significantly changed transcripts in the experimental data |
epsilon |
threshold that is used when calculating the p-value using the cubic algorithm |
useCubicAlgorithm |
use the cubic algorithm, defaults to TRUE |
use1bAlgorithm |
use the 1b version of the algorithm, defaults to TRUE used to calculate the p-value |
the resulting p-value
CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm(5, c(7,4,19), c(6,6,18), 1e-5)CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm(5, c(7,4,19), c(6,6,18), 1e-5)
Calculates the p-value of a score given the hypothesis score and the distribution table (calculated using the cubic algorithm)
CalculateSignificanceUsingCubicAlgorithm(hypothesisScore, predictionListStats, experimentalDataStats, epsilon)CalculateSignificanceUsingCubicAlgorithm(hypothesisScore, predictionListStats, experimentalDataStats, epsilon)
hypothesisScore |
the score whose p-value we want to find. |
predictionListStats |
numbers of predicted up-regulated, predicted down-regulated and ambiguous predictions. |
experimentalDataStats |
numbers of up-regulated, down-regulated and not significantly changed transcripts in the experimental data. |
epsilon |
an epsilon threshold that is used when calculating the p-value using the cubic algorithm. Defaults to 1e-5. |
p-value
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm(5, c(7,4,19), c(6,6,18), 1e-5)CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm(5, c(7,4,19), c(6,6,18), 1e-5)
Calculate the p-value of a score given the hypothesis score and the distribution table (calculated using the cubic algorithm 1b in Assessing statistical significance in causal graphs - Chindelevitch et al)
CalculateSignificanceUsingCubicAlgorithm1b(hypothesisScore, predictionListStats, experimentalDataStats, epsilon)CalculateSignificanceUsingCubicAlgorithm1b(hypothesisScore, predictionListStats, experimentalDataStats, epsilon)
hypothesisScore |
The score whose p-value we want to find. |
predictionListStats |
Number of predicted up-regulated, predicted down-regulated and ambiguous predictions. |
experimentalDataStats |
Number of up-regulated, down-regulated and not significantly changed transcripts in the experimental data. |
epsilon |
The threshold that is used when calculating the p-value using the cubic algorithm. (Defaults to 1e-5, only used for the cubic algorithm, ignored if useCubicAlgorithm is FALSE.) |
p value
CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm1b(5, c(7,4,19), c(6,6,18), 1e-5)CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm1b(5, c(7,4,19), c(6,6,18), 1e-5)
Computes the significance of a given hypothesis. For a detailed description of the algorithm see Causal reasoning on biological networks: interpreting transcriptional changes - Chindelevitch et al., section 2. from which the methods and notation is taken.
CalculateSignificanceUsingQuarticAlgorithm(hypothesisScore, predictionListStats, experimentalDataStats)CalculateSignificanceUsingQuarticAlgorithm(hypothesisScore, predictionListStats, experimentalDataStats)
hypothesisScore |
the score for which a p-value is required |
predictionListStats |
a vector containing the values q+, q- and q0 (the number of positive/negative/non-significant or contradictory) predictions) |
experimentalDataStats |
a vector containing the values n+, n- and n0 (the number of positive/negative/non-significant (or contradictory) transcripts in the results) (or contradictory) transcripts in the results) |
the corresponding p-value
L Chindelevitch et al. Causal reasoning on biological networks: Interpreting transcriptional changes. Bioinformatics, 28(8):1114-21, 2012.
CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm(5, c(7,4,19), c(6,6,18), 1e-5)CalculateSignificance(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=TRUE) CalculateSignificanceUsingQuarticAlgorithm(5, c(7,4,19), c(6,6,18)) CalculateSignificance(5, c(7,4,19), c(6,6,18), useCubicAlgorithm=FALSE) CalculateSignificance(5, c(7,4,19), c(6,6,18), 1e-5) CalculateSignificance(5, c(7,4,19), c(6,6,18), epsilon=1e-5, useCubicAlgorithm=TRUE) CalculateSignificanceUsingCubicAlgorithm(5, c(7,4,19), c(6,6,18), 1e-5)
Calculates the total weights or D-values for all possible contingency tables. This value can be used to calculate the p-value
CalculateTotalWeightForAllContingencyTables(experimentalDataStats, returnlog = FALSE)CalculateTotalWeightForAllContingencyTables(experimentalDataStats, returnlog = FALSE)
experimentalDataStats |
a vector containing the values n+, n- and n0, the number of positive/negative/non-significant (or contradictory) transcripts in the results |
returnlog |
whether the result should be returned as a log. Default is FALSE. |
a D-value or weight
Given the values in the three by three contingency table and the values of the number of positive/negative/non-significant predictions (q+, q-, q0) this function calculates the D-value (or weight).
CalculateWeightGivenValuesInThreeByThreeContingencyTable(threeByThreeContingencyTable, logOfFactorialOfPredictionListStats, returnlog = FALSE)CalculateWeightGivenValuesInThreeByThreeContingencyTable(threeByThreeContingencyTable, logOfFactorialOfPredictionListStats, returnlog = FALSE)
threeByThreeContingencyTable |
a 3x3 contingency table |
logOfFactorialOfPredictionListStats |
log of Factorial of prediction statistics |
returnlog |
should the result be returned as a log value. Default is FALSE. |
a D-value (or weight)
Checks if the a given set of possible values for n++, n+-, n-+ and n– are agree with the predicted and experimental data
CheckPossibleValuesAreValid(predictionDataStats, experimentalDataStats, possibleValues)CheckPossibleValuesAreValid(predictionDataStats, experimentalDataStats, possibleValues)
predictionDataStats |
a vector of predicted results |
experimentalDataStats |
a vector of observed experimental results |
possibleValues |
a vector of possible values n++, n+-, n-+ and n– |
TRUE if and only if the given vector of possible values is valid
Checkes to see if the values of r+, r-, c+ and c- which are stored in rowAndColumnSumValues define a valid contingency table
CheckRowAndColumnSumValuesAreValid(rowAndColumnSumValues, predictionListStats, experimentalResultStats)CheckRowAndColumnSumValuesAreValid(rowAndColumnSumValues, predictionListStats, experimentalResultStats)
rowAndColumnSumValues |
a 4x1 vector containing the row and column sum values (r+, r-, c+, c-) for a 2x2 contingency table |
predictionListStats |
a vector containing the values q+, q- and q0 |
experimentalResultStats |
A vector containing the values n+, n- and n0 |
TRUE if the table is valid; otherwise FALSE
Compare the predictions from a hypothesis with the experimental data returning an matrix with columns for node ID, predictions, experimental results and the corresponding scores.
CompareHypothesis(matrixOfPredictions, matrixOfExperimentalData, ccg = NULL, sourceNode = NULL)CompareHypothesis(matrixOfPredictions, matrixOfExperimentalData, ccg = NULL, sourceNode = NULL)
matrixOfPredictions |
a matrix of predictions |
matrixOfExperimentalData |
a matrix of experimental data |
ccg |
a CCG network (default=NULL) |
sourceNode |
A starting node (default=NULL) |
a matrix containing predictions, observations and scores.
predictions <- matrix(c(1,2,3,+1,0,-1),ncol=2) experimentalData <- matrix(c(1,2,4,+1,+1,-1),ncol=2) ScoreHypothesis(predictions,experimentalData) CompareHypothesis(predictions,experimentalData)predictions <- matrix(c(1,2,3,+1,0,-1),ncol=2) experimentalData <- matrix(c(1,2,4,+1,+1,-1),ncol=2) ScoreHypothesis(predictions,experimentalData) CompareHypothesis(predictions,experimentalData)
Computes a final reference distribution of the score used to compute the final p-value.
ComputeFinalDistribution(resultsMatrix)ComputeFinalDistribution(resultsMatrix)
resultsMatrix |
a matrix containing the scores and weights from which the distribution is to be calculated |
distributionMatrix a matrix containing the reference distribution for the score
Computes the p-value of the score of an hypothesis, based on a distribution table
ComputePValueFromDistributionTable(scoreOfHypothesis, distributionMatrix, totalWeights)ComputePValueFromDistributionTable(scoreOfHypothesis, distributionMatrix, totalWeights)
scoreOfHypothesis |
a score of hypothesis |
distributionMatrix |
a distribution table presented as a matrix |
totalWeights |
a matrix of total weights |
a p-value
Creates a computational causal graph from a network file.
CreateCCG(filename, nodeInclusionFile = NULL, excludeNodesInFile = TRUE)CreateCCG(filename, nodeInclusionFile = NULL, excludeNodesInFile = TRUE)
filename |
file name of the network file (in .sif file format) |
nodeInclusionFile |
optional path to a text file listing nodes to exclude in the CCG (or include - see argument excludeNodesInFile). |
excludeNodesInFile |
flag to determine if nodes in inclusion file should be taken as nodes to include or nodes to exclude. Default is TRUE to exclude. |
an igraph object containing the CCG.
CreateCG and CreateCCG create causal and computational causal graphs respectively.
L Chindelevitch et al. Causal reasoning on biological networks: Interpreting transcriptional changes. Bioinformatics, 28(8):1114-21, 2012.
# get path to example .sif file network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') #create ccg ccg = CreateCCG(network)# get path to example .sif file network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') #create ccg ccg = CreateCCG(network)
Creates a CG network from a .sif file. Takes in a .sif file output from Cytoscape, and creates an 'igraph' representing the network. The edges will be annotated with the type of interaction and a weight (1 for activation and -1 for inhibition)
CreateCG(sifFile)CreateCG(sifFile)
sifFile |
the path of the .sif file that contains all the information about the network Load in .sif file |
a CG network
# get path to example .sif file network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') #create cg cg = CreateCG(network)# get path to example .sif file network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') #create cg cg = CreateCG(network)
Creates a network from an internal data table created from a .sif file: this function converts the data read in from the .sif file into an igraph in R.
CreateNetworkFromTable(dataTable)CreateNetworkFromTable(dataTable)
dataTable |
the data table containing the information read in from the .sif file representing the network. |
an igraph network
Determines the sign of a given path. Given a path and through the network, this function will determine if the path results in activation or inhibition. Activation is indicated by 1, inhibition by -1
DetermineInteractionTypeOfPath(network, nodesInPath)DetermineInteractionTypeOfPath(network, nodesInPath)
network |
an igraph representing the network |
nodesInPath |
an ordered list of the nodes visited on the path - note that these contain numbers which use R's internal reference to the edges |
a signed integer representing the paths sign
Finds an approximate table values to maximise D. Given the values of q+, q-, q0, n+, n- and n0 this function will produce the approximate values of n++, n+-, n-+ and n– that will maximise the D value. See Assessing statistical significance of casual graphs, page 6. The values are approximate since they need to be rounded, although the direction of rounding is not clear at this stage.
FindApproximateValuesThatWillMaximiseDValue(predictionListStats, experimentalDataStats)FindApproximateValuesThatWillMaximiseDValue(predictionListStats, experimentalDataStats)
predictionListStats |
a vector containing the values q+, q- and q0: numbers of positive, negative and non-significant/contradictory predictions |
experimentalDataStats |
a vector containing the values n+, n- and n0: numbers of positive, negative and non-significant/contradictory predictions |
a 2x2 contingency table which approximately maximises D
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
Adds the IDs of the connected nodes in a subgraph to an existing list. Given the IDs of connected nodes in the full network, this function will find the corresponding IDs in the subgraph
FindIdsOfConnectedNodesInSubgraph(idsOfConnectedNodes, subgraphOfConnectedNodes)FindIdsOfConnectedNodesInSubgraph(idsOfConnectedNodes, subgraphOfConnectedNodes)
idsOfConnectedNodes |
a list of connected nodes in the full graph |
subgraphOfConnectedNodes |
a subgraph |
a list of connected nodes in the subgraph
computes the maximum possible D-value for given values q+, q-, q0 and n+, n-, n0.
FindMaximumDValue(predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)FindMaximumDValue(predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
predictionListStats |
a vector containing the predicted values q+, q- and q0: numbers of positive, negative and non-significant/contradictory predictions |
experimentalDataStats |
A vector containing the observed values n+, n- and n0: numbers of positive, negative and non-significant/contradictory observations |
logOfFactorialOfPredictionListStats |
a vector containing the log of the factorial value for each entry in predictionListStats |
returnlog |
should the result be returned as a log; default FALSE |
the maximum possible D value
Returns all possible rounding combinations of a 2x2 table. Given the values of n++, n+-, n-+ and n– (stored in twoByTwoContingencyTable) this function will compute all possibilities of rounding each value up or down.
GetAllPossibleRoundingCombinations(twoByTwoContingencyTable)GetAllPossibleRoundingCombinations(twoByTwoContingencyTable)
twoByTwoContingencyTable |
Approximate values of n++, n+-, n-+ and n–, these values are calculated to optimise the D-value (see page 6 of Assessing statistical significance of causal graphs) |
a matrix of rounding combinations
Computes an approximate maximum D value (or weight) for a superfamily (3x2 table). The result is only approximate as only the first valid D value that is return. This has been done to speed up the overall algorithm.
GetApproximateMaximumDValueFromThreeByTwoContingencyTable(threeByTwoContingencyTable, predictionListStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)GetApproximateMaximumDValueFromThreeByTwoContingencyTable(threeByTwoContingencyTable, predictionListStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
threeByTwoContingencyTable |
approximate values of n++, n+-, n-+, n–, n0+ and n0-, these values are calculated to optimise the D-value (see page 6 of Assessing statistical significance of causal graphs) |
predictionListStats |
a vector containing the values q+, q- and q0 (the number of positive/negative/non-significant (or contradictory) predictions) |
logOfFactorialOfPredictionListStats |
a vector containing the log of the factorial value for each entry in predictionListStats |
returnlog |
return the result as a log, default is FALSE |
an approximate maximum D value or weight
Computes an approximate maximum D value (or weight). The calculation is approximate since only the first valid D value that is round. This has been done to speed up the overall algorithm - to get the exact answer use GetMaximumDValueFromTwoByTwoContingencyTable.
GetApproximateMaximumDValueFromTwoByTwoContingencyTable(n_pp, n_pm, n_mp, n_mm, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)GetApproximateMaximumDValueFromTwoByTwoContingencyTable(n_pp, n_pm, n_mp, n_mm, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
n_pp |
the count n++ from the prediction-observation contingency matrix |
n_pm |
the count n+- from the prediction-observation contingency matrix |
n_mp |
the count n-+ from the prediction-observation contingency matrix |
n_mm |
the count n– from the prediction-observation contingency matrix |
predictionListStats |
a vector containing the values q+, q- and q0: the number of positive, negative, non-significant/contradictory predictions |
experimentalDataStats |
a vector containing the values n+, n- and n0: the number of positive, negative, non-significant/contradictory observations |
logOfFactorialOfPredictionListStats |
a vector containing the log of the factorial value for each entry in predictionListStats |
returnlog |
return the result as a log, default is FALSE |
the maximum D value or weight
Returns the numbers of correct and incorrect positive and negative predictions
GetCombinationsOfCorrectandIncorrectPredictions(predictionDataStats, experimentalDataStats)GetCombinationsOfCorrectandIncorrectPredictions(predictionDataStats, experimentalDataStats)
predictionDataStats |
prediction data statistics table |
experimentalDataStats |
Experimental data statistics table |
a matrix the numbers of correct and incorrect positive and negative prediction
Returns a table of node names and values for explained nodes, I.e. nodes that appear in both network and data with the same sign. The table contain the name in column 1 and the value (1 or -1) in column 2
GetExplainedNodesOfCCG(hypothesisnode, signOfHypothesis, network, experimentalData, delta)GetExplainedNodesOfCCG(hypothesisnode, signOfHypothesis, network, experimentalData, delta)
hypothesisnode |
a hypothesis node |
signOfHypothesis |
the direction of change of hypothesis node |
network |
a computational causal graph |
experimentalData |
The experimental data read in using ReadExperimentalData. The results is an n x 2 matrix; where the first column contains the node ids of the nodes in the network that the results refer to. The second column contains values indicating the direction of regulation in the results - (+)1 for up, -1 for down and 0 for insignificant amounts of regulation. The name of the first column is the filename the data was read from. |
delta |
the number of edges across which the hypothesis should be followed |
vector of explained nodes
Gets the interaction information from the input data
GetInteractionInformation(dataTable)GetInteractionInformation(dataTable)
dataTable |
a data table containing the information read in from the .sif file representing the network. |
a vector of interaction information
Get a matrix of causal relationships from the network and the IDs of connected nodes
GetMatrixOfCausalRelationships(hypothesis, network, idsOfConnectedNodesFromSubgraph)GetMatrixOfCausalRelationships(hypothesis, network, idsOfConnectedNodesFromSubgraph)
hypothesis |
a hypothesis node |
network |
a CCG network |
idsOfConnectedNodesFromSubgraph |
a list of connected nodes in the subgraph of interest |
causal relationships matrix
Computes the maximum D value for a particular family - denoted as D_fam on page 6 of Assessing Statistical Signifcance of Causal Graphs
GetMaxDValueForAFamily(r_p, r_m, c_p, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)GetMaxDValueForAFamily(r_p, r_m, c_p, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
r_p |
row sum r+ |
r_m |
row sum r- |
c_p |
column sum c+ |
predictionListStats |
approximate values of n++, n+-, n-+ and n– |
experimentalDataStats |
a vector containing the values q+, q- and q0: number of positive, negative, non-significant/contradictory predictions |
logOfFactorialOfPredictionListStats |
a vector containing the values n+, n- and n0: number of positive, negative, non-significant/contradictory observations |
returnlog |
return result as log, default value is FALSE |
the maximum DFam Value
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
Returns the maximum D value for a particular family as described as D_fam on pages 6 and 7 of Assessing Statistical Significance of Causal Graphs in Assessing Statistical Signifcance of Causal Graphs
GetMaxDValueForAThreeByTwoFamily(r_p, r_m, r_z, n_p, n_m, predictionListStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)GetMaxDValueForAThreeByTwoFamily(r_p, r_m, r_z, n_p, n_m, predictionListStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
r_p |
a r+ row sum from the prediction-observation matrix |
r_m |
a r- row sum from the prediction-observation matrix |
r_z |
a r0 row sum from the prediction-observation matrix |
n_p |
a number of predicted increases from the prediction-observation matrix |
n_m |
a number of predicted decreases from the prediction-observation matrix |
predictionListStats |
a vector contain the number of postive, negative and non-significant/contradictory predictions: q+, q- and q0. |
logOfFactorialOfPredictionListStats |
a vector containing the log of the factorial for each element in the predictionListStats object |
returnlog |
whether or not the maximum D value should be returned as a log (TRUE). Otherwise a non-logged value is returned. |
Maximum D_fam Value
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
Computes the maximum D value (or weight) given approximate values of n++, n+-, n-+ and n–. These values are approximate and in general are non-integer values; they are found by using an approximation detailed in the paper Assessing statistical significance in causal graphs on page 6 i.e. n_ab is approximately equal to q_a*n_b/t where a and b are either +, - or 0. The value is an approximation since the direction in which the number should be rounded is not clear and hence this function runs through all possible combinations of rounding before concluding the maximum D-value.
GetMaximumDValueFromTwoByTwoContingencyTable(twoByTwoContingencyTable, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)GetMaximumDValueFromTwoByTwoContingencyTable(twoByTwoContingencyTable, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
twoByTwoContingencyTable |
approximate values of n++, n+-, n-+ and n–, these values arecalculated to optimise the D-value |
predictionListStats |
a vector containing the values q+, q- and q0 the number of positive/negative/non-significant (or contradictory) predictions) |
experimentalDataStats |
a vector containing the values n+, n- and n0 (the number of positive/negative/non-significant (or contradictory) transcripts in the results) |
logOfFactorialOfPredictionListStats |
a vector containing the log of the factorial value for each entry in predictionListStats |
returnlog |
whether or not he value should be returned as a log (TRUE) or not (FALSE) |
the maximal D-value
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
Returns the CCG node ID from a node name or a vector of node names and a given direction of regulation.
GetNodeID(network, nodename, direction = 1)GetNodeID(network, nodename, direction = 1)
network |
a CCG object |
nodename |
the node name, or names, for which the ID is required |
direction |
the direction of regulation of the required node or nodes. Maybe +1 (default) or -1. |
a scalar or vector containing the node ID or IDs requested
Returns the node name from one or more node IDs, or substitute node names for node IDs, given in first column of a matrix typically of predictions or experimental data
GetNodeName(network, nodeID, signed = FALSE)GetNodeName(network, nodeID, signed = FALSE)
network |
Built from igraph |
nodeID |
a node ID or a matrix containing node IDs in its first column |
signed |
whether or not the node name should be signed. Setting this value to TRUE gives a signed name indicating whether the gene is up or down regulated in the network |
a node name or a vector of node names depending if the input is an matrix.
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg = CreateCCG(network) nodeID <- 10 GetNodeName(ccg, nodeID)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg = CreateCCG(network) nodeID <- 10 GetNodeName(ccg, nodeID)
Counts the number of entries in the in the second column of an input table that are +1 or -1.
GetNumberOfPositiveAndNegativeEntries(dataList)GetNumberOfPositiveAndNegativeEntries(dataList)
dataList |
an array or dataframe in which the second column is numeric |
a vector of two components, the first of which giving the number of +1 entries, the second the number of -1's.
expData<-read.table(system.file(package='CausalR', 'extdata', 'testData.txt')) GetNumberOfPositiveAndNegativeEntries(expData)expData<-read.table(system.file(package='CausalR', 'extdata', 'testData.txt')) GetNumberOfPositiveAndNegativeEntries(expData)
Converts network paths into Simple interaction file (.sif) format for importing into Cytoscape
GetPathsInSifFormat(arrayOfPaths)GetPathsInSifFormat(arrayOfPaths)
arrayOfPaths |
an array of paths (in the format outputted by GetShortestPathsFromCCG) to be converted to .sif format |
network visualisation
This function will compute the nodes regulated by the given hypothesis gene and write the results to a file
GetRegulatedNodes(PPInet, Expressiondata, delta, hypothesisGene = "", signOfHypothesis = 1, outputfile = "")GetRegulatedNodes(PPInet, Expressiondata, delta, hypothesisGene = "", signOfHypothesis = 1, outputfile = "")
PPInet |
a protein-protein interaction network |
Expressiondata |
a table of observed gene expression data |
delta |
the number of edges to follow along the network. This should typically be between 1 and 5 dependent on network size/topology |
hypothesisGene |
the name of the hypothesis gene |
signOfHypothesis |
the sign of action expected from the hypothesis, +1 for up regulation, -1 for down |
outputfile |
the file to which the results should be written |
Nodes regulated by hypothesis gene
Returns the possible values of r+, r-, c+ and c- (the column and row sum values) following page 6 of Assessing statistical significance in causal graphs (Chindelevitch et. al)
GetRowAndColumnSumValues(predictionListStats, experimentalResultStats)GetRowAndColumnSumValues(predictionListStats, experimentalResultStats)
predictionListStats |
a vector containing the number of postive, negative, or non-signficant/contradictory predictions (q+, q- and q0) |
experimentalResultStats |
a vector containing the number of postive, negative, or non-signficant/contradictory observations (n+, n- and n0) |
a matrix of row and sum values r+, r-, c+ and c-
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
Returns the score based on the values of n++, n+-, n-+ and n–
GetScoreForNumbersOfCorrectandIncorrectPredictions(matrixRow)GetScoreForNumbersOfCorrectandIncorrectPredictions(matrixRow)
matrixRow |
a row af a matrix of correct and incorrect prediction scores |
the corresponding score for the given row
A helper function for RankTheHypotheses to calculate a line of the scoresMatrix table
GetScoresForSingleNode(iNode, timeToRunSoFar, nodesToBeTested, network, delta, processedExperimentalData, numPredictions, epsilon, useCubicAlgorithm, use1bAlgorithm, symmetricCCG, correctPredictionsThreshold, experimentalDataStats, quiet)GetScoresForSingleNode(iNode, timeToRunSoFar, nodesToBeTested, network, delta, processedExperimentalData, numPredictions, epsilon, useCubicAlgorithm, use1bAlgorithm, symmetricCCG, correctPredictionsThreshold, experimentalDataStats, quiet)
iNode |
this node |
timeToRunSoFar |
the time to run so far |
nodesToBeTested |
List of all nodes to be tested |
network |
Computational Causal Graph, as an igraph. |
delta |
Distance to search within the causal graph. |
processedExperimentalData |
The processed experimental data |
numPredictions |
The number of predictions |
epsilon |
The threshold that is used when calculating the p-value using the cubic algorithm (see 'Assessing statistical significance in causal graphs'). |
useCubicAlgorithm |
An indicator specifying which algorithm will be used to calculate the p-value. The default is set as useCubicAlgorithm = TRUE which uses the cubic algorithm. If this value is set as FALSE, the algorithm will use the much slower quartic algorithm which does compute the exact answer, as opposed to using approximations like the cubic algorithm. |
use1bAlgorithm |
An indicator specifying whether the 1a or 1b (default, faster) variant of the cubic algorithm described in Chindelevitch's paper will be used to calculate the p-value. |
symmetricCCG |
This flag specifies whether the CCG is assumed to be symmetric. The value is set as TRUE as a default. If this is the case the running time of the algorithm is reduced since the negative node values can be calculated using symmetry and the results of calculations performed for the positive node |
correctPredictionsThreshold |
A threshold on the number of correct predictions for a given hypothesis. If a hypothesis produces fewer correct predictions than predictionsThreshold then the algorithm will not calculate the two p-values. Instead 'NA' will be displayed in the final two columns of the corresponding row of the results table. As a default correctPredictionsThreshold is set as -Inf, so that the p-values are calculated for all specified hypotheses. Note: Set to Inf to turn off p-value calculations entirely. |
experimentalDataStats |
Stats from the experimental data |
quiet |
a flag to supress progress output |
If symmetricCCG is false, this returns a single line of the scoreMatrix for the 'iNode'th node in nodesToBeTested. If symmetricCCG is true this returns two lines. The first of which corresponds to the positive node and the second the negative node.
Computes the score and weight for a network/set of experimental data based on the table containing possible values of n++, n+-, n-+ and n–.
GetScoresWeightsMatrix(matrixOfPossibleValues, predictionDataStats, experimentalDataStats, logOfFactorialOfPredictionListStats)GetScoresWeightsMatrix(matrixOfPossibleValues, predictionDataStats, experimentalDataStats, logOfFactorialOfPredictionListStats)
matrixOfPossibleValues |
values of n++, n+-, n-+ and n– that need to be assessed |
predictionDataStats |
a table of predicions |
experimentalDataStats |
a table of observed experimental data |
logOfFactorialOfPredictionListStats |
a vector containing the log of the factorial value for each entry in predictionListStats |
a matrix containing scores and logs of the weights
Implements the cubic algorithm as described on pages 6 and 7 of Assessing statistical significance in causal graphs, Chindelevitch et al. 2012
GetScoresWeightsMatrixByCubicAlg(predictionListStats, experimentalDataStats, epsilon)GetScoresWeightsMatrixByCubicAlg(predictionListStats, experimentalDataStats, epsilon)
predictionListStats |
a vector containing the values q+, q- and q0 |
experimentalDataStats |
a vector containing the values n+, n- and n0 |
epsilon |
the algorithms tolerance epsilon |
a matrix containing the ternary dot product distribution
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
Gets the set of differentially expressed genes in the results, G+ as defined by in Causal reasoning on biological networks: Interpreting transcriptional changes, L Chindelevitch et al.
GetSetOfDifferentiallyExpressedGenes(results)GetSetOfDifferentiallyExpressedGenes(results)
results |
a table of results |
a matrix of differentially expressed genes
L Chindelevitch et al. Causal reasoning on biological networks: Interpreting transcriptional changes. Bioinformatics, 28(8):1114-21, 2012.
Gets the set of positive and negative predictions, the combination of the sets Sh+ and Sh- in Causal reasoning on biological networks: Interpreting transcriptional changes, L Chindelevitch et al.
GetSetOfSignificantPredictions(predictions)GetSetOfSignificantPredictions(predictions)
predictions |
a table of predictions |
a matrix of positive and negative predictions
L Chindelevitch et al. Causal reasoning on biological networks: Interpreting transcriptional changes. Bioinformatics, 28(8):1114-21, 2012.
Gets the node names in the shortest path from one node in a CCG to another
GetShortestPathsFromCCG(network, hypothesisnode, targetnode, showbothdirs = FALSE, quiet = FALSE)GetShortestPathsFromCCG(network, hypothesisnode, targetnode, showbothdirs = FALSE, quiet = FALSE)
network |
built from iGraph |
hypothesisnode |
hypothesis node ID |
targetnode |
target node ID |
showbothdirs |
where multiple paths from a positive and negative node, FALSE returns only the shortest. Otherwise both are returned. |
quiet |
a flag to suppress output to console. FALSE by default. |
a list of vectors containing the nodes of individual paths
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg = CreateCCG(network) hypothesisnode = 1 targetnode = 10 GetShortestPathsFromCCG (ccg, hypothesisnode, targetnode)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg = CreateCCG(network) hypothesisnode = 1 targetnode = 10 GetShortestPathsFromCCG (ccg, hypothesisnode, targetnode)
Gets the weight based on the values of n++, n+-, n-+ and n–.
GetWeightForNumbersOfCorrectandIncorrectPredictions(n_pp, n_pm, n_mp, n_mm, predictionDataStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)GetWeightForNumbersOfCorrectandIncorrectPredictions(n_pp, n_pm, n_mp, n_mm, predictionDataStats, experimentalDataStats, logOfFactorialOfPredictionListStats, returnlog = FALSE)
n_pp |
the contingency table entry n++ |
n_pm |
the contingency table entry n+- |
n_mp |
the contingency table entry n-+ |
n_mm |
the contingency table entry n– |
predictionDataStats |
prediction data statistics |
experimentalDataStats |
experimental data statistics |
logOfFactorialOfPredictionListStats |
log of factorial of prediction list stats |
returnlog |
true if the result should be returned as a log |
none
Gets the score based on the values of n++, n+-, n-+ and n–. Used as part of a p-value calculation.
GetWeightsAboveHypothesisScoreAndTotalWeights(r_p, r_m, c_p, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, hypothesisScore, logepsDMax, logDMax)GetWeightsAboveHypothesisScoreAndTotalWeights(r_p, r_m, c_p, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, hypothesisScore, logepsDMax, logDMax)
r_p |
the row sum r+ |
r_m |
the row sum r- |
c_p |
the column sum c+ |
predictionListStats |
statistics for the prediction list |
experimentalDataStats |
statistics for the experimental data |
logOfFactorialOfPredictionListStats |
log of factorial of prediction list stats |
hypothesisScore |
the hypothesis score to be considered |
logepsDMax |
Exponential of logD Maximum value |
logDMax |
A logD Maximum value |
score data
Finds the D-Values (weights) from any 3x2 contingency tables that have a score above and including the hypothesis score. It also calculates the total weight, and returns a 2x1 vector of the two values. The ratio of these values is the p-value.
GetWeightsAboveHypothesisScoreForAThreeByTwoTable(weights, r_p, r_m, r_z, n_p, n_m, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, hypothesisScore, logepsDMax, logDMax)GetWeightsAboveHypothesisScoreForAThreeByTwoTable(weights, r_p, r_m, r_z, n_p, n_m, predictionListStats, experimentalDataStats, logOfFactorialOfPredictionListStats, hypothesisScore, logepsDMax, logDMax)
weights |
Weights |
r_p |
the row sum r+ |
r_m |
the row sum r- |
r_z |
the row sum r0 |
n_p |
the column sum n+ |
n_m |
the column sum n- |
predictionListStats |
a list of prediction statistics |
experimentalDataStats |
the observed experimental data |
logOfFactorialOfPredictionListStats |
log factorial's of prediction list stats |
hypothesisScore |
the hypothesis score to be considered |
logepsDMax |
log of epsilon logD Maximum value |
logDMax |
a logD Maximum value |
a vector containing the hypothesis score and the total weight
Returns a matrix of weights (-1,0,+1) indicating the direction of regulation from the interaction information.
GetWeightsFromInteractionInformation(interactionInfo)GetWeightsFromInteractionInformation(interactionInfo)
interactionInfo |
a central column of the .sif file, giving the type of edge interaction |
a matrix of weights corresponding the the direction of regulation
Creates a matrix of predictions for a particular hypothesis. The output is an array containing the relationship between each node and the hypothesis. The hypothesis provided will be the vertex id of one of the nodes in the network (as an integer node ID or name, including + or - for up/down regulation in the case of a CCG). The signOfHypothesis variable should be a 1 or -1, indicating up/down regulation.
MakePredictions(hypothesisnode, signOfHypothesis, network, delta, nodesInExperimentalData = NULL)MakePredictions(hypothesisnode, signOfHypothesis, network, delta, nodesInExperimentalData = NULL)
hypothesisnode |
the node in the causal graph from which predictions should be made. Can be either a (numerical) node ID or a (string) node name. |
signOfHypothesis |
whether the hypothesis node is up- or down-regulated. Should be +1 or -1. |
network |
a (Computational) Causal Graph, as an igraph. |
delta |
the distance to search within the causal graph. |
nodesInExperimentalData |
optional. Nodes to include in the output. Should be a list of node IDs. |
a matrix of predictions for the given particular hypothesis
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) predictions <- MakePredictions('NodeA', +1, ccg, 2)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) predictions <- MakePredictions('NodeA', +1, ccg, 2)
Create a matrix of predictions for a particular hypothesis starting from a network with separate nodes for up- and down-regulation (+ve and -ve). The output is an array containing the relationship between each node and the hypothesis. The hypothesis provided will be the vertex id of one of the nodes in the network (as an integer or name including + or - for up/down regulation). The signOfHypothesis variable should be a 1 or -1, indicating up/down regulation. (It generally shouldn't be necessary to reverse the sign of a node when working from a CCG, but this facility is included for consistency with MakePredictionsFromCG)
MakePredictionsFromCCG(hypothesisnode, signOfHypothesis, network, delta, nodesInExperimentalData = NULL)MakePredictionsFromCCG(hypothesisnode, signOfHypothesis, network, delta, nodesInExperimentalData = NULL)
hypothesisnode |
a hypothesis node |
signOfHypothesis |
the direction of change of hypothesis node |
network |
a computational causal graph |
delta |
the number of edges across which the hypothesis should be followed |
nodesInExperimentalData |
the number of nodes in experimental data |
an matrix containing the relationship between each node and the hypothesis
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) MakePredictionsFromCCG('NodeA', +1, ccg, 2)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) MakePredictionsFromCCG('NodeA', +1, ccg, 2)
Create a matrix of predictions for a particular hypothesis - the output is a matrix containing the relationship between each node and the hypothesis. The hypothesis provided will be the vertex id of one of the nodes in the network (as an integer). The signOfHypothesis variable should be a 1 or -1, indicating up/down regulation
MakePredictionsFromCG(hypothesisnode, signOfHypothesis, network, delta, nodesInExperimentalData = NULL)MakePredictionsFromCG(hypothesisnode, signOfHypothesis, network, delta, nodesInExperimentalData = NULL)
hypothesisnode |
a hypothesis node |
signOfHypothesis |
the direction of change of hypothesis node |
network |
a computational causal graph |
delta |
the number of edges across which the hypothesis should be followed |
nodesInExperimentalData |
the number of nodes in experimental data |
an matrix containing the relationship between each node and the hypothesis
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') cg <- CreateCG(network) MakePredictionsFromCG('NodeA', +1, cg, 2)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') cg <- CreateCG(network) MakePredictionsFromCG('NodeA', +1, cg, 2)
Ranks the hypotheses. Takes a matrix containing the scores for each node of the network, and ranks them placing the hypothesis with the most correct predictions is at the top
OrderHypotheses(scoresMatrix)OrderHypotheses(scoresMatrix)
scoresMatrix |
a matrix containing the scores for each node of the network |
a ranked table of hypotheses
Plots an igraph with the node names. Plots a igraph to the screen displaying the names of the nodes input rather than R's internal numbering.
PlotGraphWithNodeNames(igraph)PlotGraphWithNodeNames(igraph)
igraph |
internal an igraph representation of an interaction network |
network visualisation
network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) PlotGraphWithNodeNames(ccg)network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ccg <- CreateCCG(network) PlotGraphWithNodeNames(ccg)
Populates 3x3 signed contingency table of expected versus observed changes. Given the values of n++, n+-, n-+ and n–, calculates n0+, n0-, n+0, n-0 and n00. Notation from Chindelevitch et al. Causal reasoning on biological networks Bioinformatics (2012) paper.
PopulateTheThreeByThreeContingencyTable(n_pp, n_pm, n_mp, n_mm, predictionDataStats, experimentalDataStats)PopulateTheThreeByThreeContingencyTable(n_pp, n_pm, n_mp, n_mm, predictionDataStats, experimentalDataStats)
n_pp |
n++ contingency table entry |
n_pm |
n+- contingency table entry |
n_mp |
n-+ contingency table entry |
n_mm |
n– contingency table entry |
predictionDataStats |
a prediction data table. |
experimentalDataStats |
an experimental data table |
Vector of calculated values for n0+, n0-, n+0, n-0 and n00 - See: Chindelevitch et al.Bioinformatics (2012).
Calculates a 2x2 contingency table. Given the value of n++ and the row and column sums (r+, r-, c+, c-), Calculates the remaining values in the 2x2 contingency table i.e. n+-, n-+, and n–. See Chindelevich et al. BMC Bioinformatics (2012) paper 'Assessing Statistical significance of causal graphs' for clarification on notation.
PopulateTwoByTwoContingencyTable(rowAndColumnSumValues, n_pp)PopulateTwoByTwoContingencyTable(rowAndColumnSumValues, n_pp)
rowAndColumnSumValues |
the row and column sums (r+, r-, c+, c-). |
n_pp |
the value of n++. |
the completed 2x2 contingency table: n++, n+-, n-+, n–
L Chindelevitch et al. Causal reasoning on biological networks: Interpreting transcriptional changes. Bioinformatics, 28(8):1114-21, 2012.
Processes experimental data to get it into the correct form for scoring. The node names that are read in as strings acquire an internal id when the network is created. This function will replace the node name with its id.
ProcessExperimentalData(experimentalData, network)ProcessExperimentalData(experimentalData, network)
experimentalData |
input experimental data. |
network |
an input interaction network. |
processed experimental data formatted ready for scoring
Rank the hypotheses in the causal network. This function can be run with parallelisation using the doParallel flag.
RankTheHypotheses(network, experimentalData, delta, epsilon = 1e-05, useCubicAlgorithm = TRUE, use1bAlgorithm = TRUE, symmetricCCG = TRUE, listOfNodes = NULL, correctPredictionsThreshold = -Inf, quiet = FALSE, doParallel = FALSE, numCores = NULL, writeFile = TRUE, outputDir = getwd())RankTheHypotheses(network, experimentalData, delta, epsilon = 1e-05, useCubicAlgorithm = TRUE, use1bAlgorithm = TRUE, symmetricCCG = TRUE, listOfNodes = NULL, correctPredictionsThreshold = -Inf, quiet = FALSE, doParallel = FALSE, numCores = NULL, writeFile = TRUE, outputDir = getwd())
network |
Computational Causal Graph, as an igraph. |
experimentalData |
The experimental data read in using ReadExperimentalData. The results is an n x 2 matrix; where the first column contains the node ids of the nodes in the network that the results refer to. The second column contains values indicating the direction of regulation in the results - (+)1 for up, -1 for down and 0 for insignificant amounts of regulation. The name of the first column is the filename the data was read from. |
delta |
Distance to search within the causal graph. |
epsilon |
The threshold that is used when calculating the p-value using the cubic algorithm (see 'Assessing statistical significance in causal graphs'). |
useCubicAlgorithm |
An indicator specifying which algorithm will be used to calculate the p-value. The default is set as useCubicAlgorithm = TRUE which uses the cubic algorithm. If this value is set as FALSE, the algorithm will use the much slower quartic algorithm which does compute the exact answer, as opposed to using approximations like the cubic algorithm. |
use1bAlgorithm |
An indicator specifying whether the 1a or 1b (default, faster) variant of the cubic algorithm described in Chindelevitch's paper will be used to calculate the p-value. |
symmetricCCG |
This flag specifies whether the CCG is assumed to be symmetric. The value is set as TRUE as a default. If this is the case the running time of the algorithm is reduced since the bottom half of the table can be filled in using the results of calculations performed earlier. |
listOfNodes |
A list of nodes specified by the user. The algorithm will only calculate and store the results for the nodes in the specified list. The default value is NULL; here the algorithm will calculate and store results for all the nodes in the network. |
correctPredictionsThreshold |
A threshold on the number of correct predictions for a given hypothesis. If a hypothesis produces fewer correct predictions than predictionsThreshold then the algorithm will not calculate the two p-values. Instead 'NA' will be displayed in the final two columns of the corresponding row of the results table. As a default correctPredictionsThreshold is set as -Inf, so that the p-values are calculated for all specified hypotheses. |
quiet |
a flag to suppress output to console. FALSE by default. |
doParallel |
A flag for running RankTheHypothesis in parallel mode. |
numCores |
Number of cores to use if using parallel mode. If the default value of NULL is used, it will attempt to detect the number of cores available and use all of them bar one. |
writeFile |
A flag for determining if the output should be written to a file in the working directory. Default is TRUE. |
outputDir |
the directory to output the files to. Default is the working directory |
A data frame containing the results of the algorithm.
L Chindelevitch et al. Assessing statistical significance in causal graphs. BMC Bioinformatics, 13(35), 2012.
#get path to example network file networkFile <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') #create ccg network <- CreateCCG(networkFile) #get path to example experimental data experimentalDataFile <- system.file(package='CausalR', 'extdata', 'testData.txt') #read in experimetal data experimentalData <- ReadExperimentalData(experimentalDataFile, network) #run in single threaded mode RankTheHypotheses(network, experimentalData, 2) #run in parallel mode RankTheHypotheses(network, experimentalData, 2, doParallel=TRUE, numCores=2)#get path to example network file networkFile <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') #create ccg network <- CreateCCG(networkFile) #get path to example experimental data experimentalDataFile <- system.file(package='CausalR', 'extdata', 'testData.txt') #read in experimetal data experimentalData <- ReadExperimentalData(experimentalDataFile, network) #run in single threaded mode RankTheHypotheses(network, experimentalData, 2) #run in parallel mode RankTheHypotheses(network, experimentalData, 2, doParallel=TRUE, numCores=2)
Reads experimental data for the causal reasoning algorithm from a text file.
ReadExperimentalData(fileName, network, removeDuplicates)ReadExperimentalData(fileName, network, removeDuplicates)
fileName |
a file containing the experimental data (text file format) |
network |
a (Computational) Causal Graph, as an igraph. |
removeDuplicates |
Optional, defaults to true. Remove duplicated nodes the experimental file (i.e. where the result for a node is repeated, use the first value given only; the alternative is to return a result which contains multiple rows for this node). |
(n x 2) matrix of nodes and direction of regulation. The first column of the matrix contains the node IDs from the network, and the second contains the experimental values.
#get path to example network file network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ##create ccg ccg <- CreateCCG(network) #get path to example experimental data fileName<- system.file(package='CausalR', 'extdata', 'testData.txt') ReadExperimentalData(fileName, ccg)#get path to example network file network <- system.file(package='CausalR', 'extdata', 'testNetwork.sif') ##create ccg ccg <- CreateCCG(network) #get path to example experimental data fileName<- system.file(package='CausalR', 'extdata', 'testData.txt') ReadExperimentalData(fileName, ccg)
Reads a .sif file into a table in R
ReadSifFileToTable(sifFile)ReadSifFileToTable(sifFile)
sifFile |
the sifFile to be read in |
a R table containing the data from the .sif file
Takes in a list of connected nodes and removes those not in the experimental data.
RemoveIDsNotInExperimentalData(connectedNodes, nodesInExperimentalData)RemoveIDsNotInExperimentalData(connectedNodes, nodesInExperimentalData)
connectedNodes |
a list of connected nodes |
nodesInExperimentalData |
a list of nodes in the experimental data |
connectedNodesInExperimentalData a list of connected nodes with the redundant nodes removed
A top level function that used to run CausalR
runRankHypothesis(PPInet, Expressiondata, delta, correctPredictionsThreshold)runRankHypothesis(PPInet, Expressiondata, delta, correctPredictionsThreshold)
PPInet |
PPInet is the PPI interaction file |
Expressiondata |
observed gene expression data |
delta |
the number of links to follow from any hypothesis no. Dedepending on network size/topology, this value typically ranges between 1 and 5 |
correctPredictionsThreshold |
Minimal score for p-values calculation. Hypotheses with scores below this value will get NAs for p-value and enrichment p-value. The usual default is -inf within the RankTheHypotheses function, where it is employed. |
rankedHypothesis table of results produced by the algorithm
This function will return nodes regulated by the given hypothesisGene
runSCANR(network, experimentalData, numberOfDeltaToScan = 5, topNumGenes = 150, correctPredictionsThreshold = Inf, writeResultFiles = TRUE, writeNetworkFiles = "all", doParallel = FALSE, numCores = NULL, quiet = FALSE, outputDir = getwd())runSCANR(network, experimentalData, numberOfDeltaToScan = 5, topNumGenes = 150, correctPredictionsThreshold = Inf, writeResultFiles = TRUE, writeNetworkFiles = "all", doParallel = FALSE, numCores = NULL, quiet = FALSE, outputDir = getwd())
network |
Computational Causal Graph, as an igraph. |
experimentalData |
The experimental data read in using ReadExperimentalData. The results is an n x 2 matrix; where the first column contains the node ids of the nodes in the network that the results refer to. The second column contains values indicating the direction of regulation in the results - (+)1 for up, -1 for down and 0 for insignificant amounts of regulation. |
numberOfDeltaToScan |
Iteratively scan for 1 to numberOfDeltaToScan delta values |
topNumGenes |
A value to select top genes to report (typically top 100 genes) |
correctPredictionsThreshold |
Minimal score for p-values calculation. Value is passed to RankTheHypothesis - scores below this value will get NAs for p-value and enrichment p-value. The default is Inf, so that no p-values are calculated. |
writeResultFiles |
If set to TRUE the results of the scan will be written to two text files in the working directory. Default is TRUE. |
writeNetworkFiles |
If set to "all" .sif files and corresponding _anno.txt files will be generated for the top correctly explained, incorrectly explained and ambiguously explained nodes. If set to "correct" they will only be calculated for correctly explained nodes. If set to "none", no networks will be generated. Default is "all". |
doParallel |
A flag for running RankTheHypothesis in parallel mode. Default is FALSE. |
numCores |
Number of cores to use if using parallel mode. If the default value of NULL is used, it will attempt to detect the number of cores available and use all of them bar one. |
quiet |
a flag to suppress output to console. FALSE by default. |
outputDir |
the directory to output the files to. Default is the working directory |
returns list of genes from each delta scan run
numberOfDeltaToScan <- 2 topNumGenes <- 4 #get path to example network file networkFile <- system.file(package = 'CausalR', 'extdata', 'testNetwork.sif') #create ccg network <- CreateCCG(networkFile) #get path to example experimental data experimentalDataFile <- system.file(package = 'CausalR', 'extdata', 'testData.txt') #read in experimetal data experimentalData <- ReadExperimentalData(experimentalDataFile, network) #run in single threaded mode runSCANR(network, experimentalData, numberOfDeltaToScan, topNumGenes) #run in parallel mode runSCANR(network, experimentalData, numberOfDeltaToScan, topNumGenes, doParallel = TRUE, numCores = 2)numberOfDeltaToScan <- 2 topNumGenes <- 4 #get path to example network file networkFile <- system.file(package = 'CausalR', 'extdata', 'testNetwork.sif') #create ccg network <- CreateCCG(networkFile) #get path to example experimental data experimentalDataFile <- system.file(package = 'CausalR', 'extdata', 'testData.txt') #read in experimetal data experimentalData <- ReadExperimentalData(experimentalDataFile, network) #run in single threaded mode runSCANR(network, experimentalData, numberOfDeltaToScan, topNumGenes) #run in parallel mode runSCANR(network, experimentalData, numberOfDeltaToScan, topNumGenes, doParallel = TRUE, numCores = 2)
Score a single hypothesis, using the predictions from the network and the experimental data returning a vector of scoring statistics
ScoreHypothesis(matrixOfPredictions, matrixOfExperimentalData)ScoreHypothesis(matrixOfPredictions, matrixOfExperimentalData)
matrixOfPredictions |
a matrix of predictions |
matrixOfExperimentalData |
a matrix of experimentaldata |
scoreBreakdown a vector giving, in order, the overall score, and the numbers of correct, incorrect and ambigous predictions
predictions <- matrix(c(1,2,3,+1,0,-1),ncol=2) experimentalData <- matrix(c(1,2,4,+1,+1,-1),ncol=2) ScoreHypothesis(predictions,experimentalData) CompareHypothesis(predictions,experimentalData)predictions <- matrix(c(1,2,3,+1,0,-1),ncol=2) experimentalData <- matrix(c(1,2,4,+1,+1,-1),ncol=2) ScoreHypothesis(predictions,experimentalData) CompareHypothesis(predictions,experimentalData)
Checks the format of the experimental data. This is expected to be two columns, the first containing the gene name and the second the direction of regulation, -1, 0 or 1. The function checks the number of columns and the values of the second column,
ValidateFormatOfDataTable(dataTable)ValidateFormatOfDataTable(dataTable)
dataTable |
the data table to be tested |
true if the data table is valid
Checks the format of the loaded in data. In particular exepects a table with threecolumns (in order) a initiating gene, an interaction ('Activates','Inhibits') and a responding gene and checks the number of rows and the values of the middle column.
ValidateFormatOfTable(dataTable)ValidateFormatOfTable(dataTable)
dataTable |
the table to be tested |
true if the test is satisfed.
Outputs networks of all explained nodes in .sif file format, named by node name with sign of regulation, each with a corresponding annotation file for producing visualisations using Cytoscape.
WriteAllExplainedNodesToSifFile(scanResults, network, experimentalData, delta, correctlyExplainedOnly = TRUE, quiet = TRUE)WriteAllExplainedNodesToSifFile(scanResults, network, experimentalData, delta, correctlyExplainedOnly = TRUE, quiet = TRUE)
scanResults |
a results object produced by ScanR |
network |
a computational causal graph |
experimentalData |
The experimental data read in using ReadExperimentalData. |
delta |
the number of edges across which the hypothesis should be followed, the setting should be that used to generate the input ScanR object. |
correctlyExplainedOnly |
if TRUE network files will only be produced for correctly explained nodes. If FALSE network files will be produced for each of correctly explained, incorrectly explained and ambiguously explained nodes. |
quiet |
a flag to suppress output to console. FALSE by default. |
files containing paths from hypothesis node to explained nodes in sif format and corresponding annotation (_anno.txt) files
networkFile <- system.file(package='CausalR', 'extdata', 'testNetwork1.sif') network <- CreateCCG(networkFile) experimentalDataFile <- system.file(package='CausalR', 'extdata', 'testData1.txt') experimentalData <- ReadExperimentalData(experimentalDataFile, network) delta <- 2 scanResults <- runSCANR(network, experimentalData, numberOfDeltaToScan = delta, topNumGenes = 2, writeResultFiles = FALSE, writeNetworkFiles = "none", quiet = FALSE, doParallel = TRUE, numCores = 2) WriteAllExplainedNodesToSifFile(scanResults, network, experimentalData, delta, correctlyExplainedOnly = TRUE, quiet = TRUE)networkFile <- system.file(package='CausalR', 'extdata', 'testNetwork1.sif') network <- CreateCCG(networkFile) experimentalDataFile <- system.file(package='CausalR', 'extdata', 'testData1.txt') experimentalData <- ReadExperimentalData(experimentalDataFile, network) delta <- 2 scanResults <- runSCANR(network, experimentalData, numberOfDeltaToScan = delta, topNumGenes = 2, writeResultFiles = FALSE, writeNetworkFiles = "none", quiet = FALSE, doParallel = TRUE, numCores = 2) WriteAllExplainedNodesToSifFile(scanResults, network, experimentalData, delta, correctlyExplainedOnly = TRUE, quiet = TRUE)
Outputs networks of explained nodes in .sif file format for producing visualisations using Cytoscape. Output will be to a directory beginning with a timestamp,
WriteExplainedNodesToSifFile(hypothesisnode, signOfHypothesis, network, experimentalData, delta, outputDir = getwd(), outputFilesName = "", correctlyExplainedOnly = FALSE, quiet = FALSE)WriteExplainedNodesToSifFile(hypothesisnode, signOfHypothesis, network, experimentalData, delta, outputDir = getwd(), outputFilesName = "", correctlyExplainedOnly = FALSE, quiet = FALSE)
hypothesisnode |
a hypothesis node |
signOfHypothesis |
the direction of change of hypothesis node |
network |
a computational causal graph |
experimentalData |
The experimental data read in using ReadExperimentalData. The results is an n x 2 matrix; where the first column contains the node ids of the nodes in the network that the results refer to. The second column contains values indicating the direction of regulation in the results - (+)1 for up, -1 for down and 0 for insignificant amounts of regulation. The name of the first column is the filename the data was read from. |
delta |
the number of edges across which the hypothesis should be followed |
outputDir |
the directory to output the files to. Default is the working directory |
outputFilesName |
a character string to use for the name of the output files. Default value is "", which results in files using the default naming convention of "network file name-data file name-delta value-node name". Set to NA if not writing to file. |
correctlyExplainedOnly |
if TRUE network files will only be produced for correctly explained nodes. If FALSE network files will be produced for each of correctly explained, incorrectly explained and ambiguously explained nodes. |
quiet |
a flag to suppress output to console. FALSE by default. |
files containing paths from hypothesis node to explained nodes in sif format and corresponding annotation (_anno.txt) files
hypothesisnode <- "Node0" signOfHypothesis <- +1 networkFile <- system.file(package='CausalR', 'extdata', 'testNetwork1.sif') network <- CreateCCG(networkFile) experimentalDataFile <- system.file(package='CausalR', 'extdata', 'testData1.txt') experimentalData <- ReadExperimentalData(experimentalDataFile, network) delta <- 2 WriteExplainedNodesToSifFile(hypothesisnode, signOfHypothesis, network, experimentalData, delta, outputFilesName=NA)hypothesisnode <- "Node0" signOfHypothesis <- +1 networkFile <- system.file(package='CausalR', 'extdata', 'testNetwork1.sif') network <- CreateCCG(networkFile) experimentalDataFile <- system.file(package='CausalR', 'extdata', 'testData1.txt') experimentalData <- ReadExperimentalData(experimentalDataFile, network) delta <- 2 WriteExplainedNodesToSifFile(hypothesisnode, signOfHypothesis, network, experimentalData, delta, outputFilesName=NA)