Package 'StabMap' reference manual

Title:	Stabilised mosaic single cell data integration using unshared features
Description:	StabMap performs single cell mosaic data integration by first building a mosaic data topology, and for each reference dataset, traverses the topology to project and predict data onto a common embedding. Mosaic data should be provided in a list format, with all relevant features included in the data matrices within each list object. The output of stabMap is a joint low-dimensional embedding taking into account all available relevant features. Expression imputation can also be performed using the StabMap embedding and any of the original data matrices for given reference and query cell lists.
Authors:	Shila Ghazanfar [aut, cre, ctb], Aiden Jin [ctb], Nicholas Robertson [ctb]
Maintainer:	Shila Ghazanfar <[email protected]>
License:	GPL-2
Version:	1.1.0
Built:	2024-11-14 06:03:44 UTC
Source:	https://github.com/bioc/StabMap

Adaptive k-Nearest Neighbour Classification

Description

Adaptive k-Nearest Neighbour Classification for a k-nearest neighbour matrix, given class labels and local k values for the training data

Usage

adaptiveKNN(knn, class, k_local)
adaptiveKNN(knn, class, k_local)

Arguments

`knn`	Is a k-nearest neighbour matrix, giving the indices of the training set that the query is closest to. Rows are the query cells, columns are the NNs. Typically output using BiocNeighbors::queryKNN(,,k = max(k_local)).
`class`	Is the labels associated with the training set.
`k_local`	Is an integer vector length of the training set, giving the local k to use if k_local is given as a single integer, then that value is used as k for all observations.

Value

A character vector of of classifications for the test set.

Examples

# Generate example data
data <- matrix(rpois(10 * 20, 10), 10, 20) # 10 genes, 20 cells
data_2 <- matrix(rpois(10 * 30, 10), 10, 30) # 10 genes, 30 cells

# Generate error matrix for k_local
E <- matrix(runif(100), 20, 5)
colnames(E) <- paste0("K_", 1:5)

# Define training class labels and adaptive k-values
class <- factor(rep(letters[1:2], each = 10))
k_local <- getAdaptiveK(E, labels = class)

knn <- BiocNeighbors::queryKNN(
  t(data), t(data_2),
  k = max(as.numeric(gsub("K_", "", k_local)))
)$index

# Adaptive KNN classification
test <- adaptiveKNN(
  knn, class, as.numeric(gsub("K_", "", k_local))
)

# Generate example data
data <- matrix(rpois(10 * 20, 10), 10, 20) # 10 genes, 20 cells
data_2 <- matrix(rpois(10 * 30, 10), 10, 30) # 10 genes, 30 cells

# Generate error matrix for k_local
E <- matrix(runif(100), 20, 5)
colnames(E) <- paste0("K_", 1:5)

# Define training class labels and adaptive k-values
class <- factor(rep(letters[1:2], each = 10))
k_local <- getAdaptiveK(E, labels = class)

knn <- BiocNeighbors::queryKNN(
  t(data), t(data_2),
  k = max(as.numeric(gsub("K_", "", k_local)))
)$index

# Adaptive KNN classification
test <- adaptiveKNN(
  knn, class, as.numeric(gsub("K_", "", k_local))
)

Adaptive k-Nearest Neighbour Classification using the StabMap joint embedding

Description

Performs adaptive k-nearest neighbour classification of discrete labels for a training set from a query set, leveraging the StabMap joint embedding. The training labels are defined in 'labels', with all other rows of the embedding treated as the testing set.

Usage

classifyEmbedding(
  coords,
  labels,
  type = c("uniform_fixed", "adaptive_labels", "adaptive_local", "uniform_optimised"),
  k_values = 5,
  error_measure = c("simple_error", "balanced_error"),
  adaptive_nFold = 2,
  adaptive_nRep = 5,
  adaptive_local_nhood = 100,
  adaptive_local_smooth = 10,
  verbose = TRUE
)
classifyEmbedding(
  coords,
  labels,
  type = c("uniform_fixed", "adaptive_labels", "adaptive_local", "uniform_optimised"),
  k_values = 5,
  error_measure = c("simple_error", "balanced_error"),
  adaptive_nFold = 2,
  adaptive_nRep = 5,
  adaptive_local_nhood = 100,
  adaptive_local_smooth = 10,
  verbose = TRUE
)

Arguments

`coords`	A cells (rows) x dimensions data matrix, on which euclidean distances are to be calculated for KNN classification. Must have rownames. Typically, output from 'stabMap()'.
`labels`	A named character vector of labels for the training set.
`type`	A character of the type of adaptive KNN classification to be used. Must be one of "adaptive_local", "adaptive_labels", "uniform_optimised", or "uniform_fixed". Default is "uniform_fixed".
`k_values`	A numeric vector of potential k values. If type is "uniform_fixed", then the first value of k_values is used. Default is 5.
`error_measure`	Is the error type to use for selection of the best k. Must be one of "simple_error" or "balanced_error". "simple_error" weights all cells equally. "balanced_error" weights error by 'labels' factors. Only affects error type for type == "uniform_optimised".
`adaptive_nFold`	Is the number of folds for adaptive selection cross-validation.
`adaptive_nRep`	Is the number of repetitions of adaptive selection cross-validation.
`adaptive_local_nhood`	Is the neighbourhood size for optimising locally.
`adaptive_local_smooth`	Is the number of neighbours to use for smoothing locally.
`verbose`	Logical whether to print repetition and fold number for adaptive selection cross-validation.

Value

Is a dataframe with rows the same as coords, and same rownames. Columns are: input_labels is the training labels that were provided in 'labels' (NA is used as labels for the testing set), resubstituted_labels is predicted labels for all rows (including for the training data), predicted_labels is predicted labels for the testing set but true labels as provided in 'labels' for the training set, k is the adaptive k value used for that each row of the training set.

Examples

set.seed(100)
# Simulate coordinates
coords <- matrix(rnorm(1000), 100, 10)
rownames(coords) <- paste0("cell_", seq_len(nrow(coords)))

# Define labels of the first 50 cells
labels <- rep(paste0("type_", letters[1:5]), 10)
names(labels) <- rownames(coords)[seq_along(labels)]

# Uniform fixed KNN classification
knn_out <- classifyEmbedding(
  coords, labels,
  type = "uniform_fixed", k_values = 5
)
table(knn_out$predicted_labels)

# Adaptive KNN classification using local error
knn_out <- classifyEmbedding(
coords, labels,
type = "adaptive_local",
k_values = 2:3,
adaptive_nFold = 5,
adaptive_nRep = 10
)
table(knn_out$predicted_labels)

knn_out <- classifyEmbedding(
  coords, labels,
  type = "adaptive_labels",
  k_values = 2:3,
  adaptive_nFold = 5,
  adaptive_nRep = 10
)
table(knn_out$predicted_labels)

# Adaptive KNN classification using uniform optimised with balanced error
knn_out <- classifyEmbedding(
  coords, labels,
  type = "uniform_optimised",
  k_values = 2:3,
  adaptive_nFold = 3,
  adaptive_nRep = 10,
  error_measure = "balanced_error"
)
table(knn_out$predicted_labels)

set.seed(100)
# Simulate coordinates
coords <- matrix(rnorm(1000), 100, 10)
rownames(coords) <- paste0("cell_", seq_len(nrow(coords)))

# Define labels of the first 50 cells
labels <- rep(paste0("type_", letters[1:5]), 10)
names(labels) <- rownames(coords)[seq_along(labels)]

# Uniform fixed KNN classification
knn_out <- classifyEmbedding(
  coords, labels,
  type = "uniform_fixed", k_values = 5
)
table(knn_out$predicted_labels)

# Adaptive KNN classification using local error
knn_out <- classifyEmbedding(
coords, labels,
type = "adaptive_local",
k_values = 2:3,
adaptive_nFold = 5,
adaptive_nRep = 10
)
table(knn_out$predicted_labels)

knn_out <- classifyEmbedding(
  coords, labels,
  type = "adaptive_labels",
  k_values = 2:3,
  adaptive_nFold = 5,
  adaptive_nRep = 10
)
table(knn_out$predicted_labels)

# Adaptive KNN classification using uniform optimised with balanced error
knn_out <- classifyEmbedding(
  coords, labels,
  type = "uniform_optimised",
  k_values = 2:3,
  adaptive_nFold = 3,
  adaptive_nRep = 10,
  error_measure = "balanced_error"
)
table(knn_out$predicted_labels)

Adaptive k selection for KNN classification

Description

Given an error matrix, identify the k that maximises the accuracy for cells belonging to a provided labelling/grouping. If no labelling given, expect a cell-cell similarity network to identify the k that maximises the accuracy for cells within that neighbourhood. If neither are given, simply treat all cells as if they have the same labelling/grouping

Usage

getAdaptiveK(E, labels = NULL, local = NULL, outputPerCell = TRUE, ...)
getAdaptiveK(E, labels = NULL, local = NULL, outputPerCell = TRUE, ...)

Arguments

`E`	An error matrix with rows corresponding to cells and columns corresponding to candidate k values, with values themselves corresponding to error values (either binary for single classification, or continuous after multiple classification).
`labels`	Group labels for cells.
`local`	A neighbourhood index representation, as typically output using BiocNeighbors::findKNN().
`outputPerCell`	Logical whether to return adaptive k for each cell, not just for each label type (used for when labels is given).
`...`	Includes return_colnames, whether to give the colnames of the best selected, or just the index, which is default TRUE.

Value

Vector of adaptive k values.

Examples

E <- matrix(runif(100), 20, 5)
colnames(E) <- paste0("K_", 1:5)

# generate cell labels
labels <- factor(rep(letters[1:2], each = 10))

# generate nearest neighbourhood index representation
data <- matrix(rpois(10 * 20, 10), 10, 20) # 10 genes, 20 cells
local <- BiocNeighbors::findKNN(t(data), k = 5, get.distance = FALSE)$index

best_k_labels <- getAdaptiveK(E,
  labels = labels
)
best_k_local <- getAdaptiveK(E,
  local = local
)

E <- matrix(runif(100), 20, 5)
colnames(E) <- paste0("K_", 1:5)

# generate cell labels
labels <- factor(rep(letters[1:2], each = 10))

# generate nearest neighbourhood index representation
data <- matrix(rpois(10 * 20, 10), 10, 20) # 10 genes, 20 cells
local <- BiocNeighbors::findKNN(t(data), k = 5, get.distance = FALSE)$index

best_k_labels <- getAdaptiveK(E,
  labels = labels
)
best_k_local <- getAdaptiveK(E,
  local = local
)

Impute values using StabMap joint embedding

Description

Performs naive imputation of values from the list of mosaic data and joint embedding from StabMap.

Usage

imputeEmbedding(
  assay_list,
  embedding,
  reference = Reduce(union, lapply(assay_list, colnames)),
  query = Reduce(union, lapply(assay_list, colnames)),
  neighbours = 5,
  fun = mean
)
imputeEmbedding(
  assay_list,
  embedding,
  reference = Reduce(union, lapply(assay_list, colnames)),
  query = Reduce(union, lapply(assay_list, colnames)),
  neighbours = 5,
  fun = mean
)

Arguments

`assay_list`	List of mosaic data from which to perform imputation.
`embedding`	Joint embedding from which to extract nearest neighbour relationships.
`reference`	Character vector of cell names to treat as reference cells.
`query`	Character vector of cell names to treat as query cells.
`neighbours`	Number of nearest neighbours to consider (default 5).
`fun`	function (default ‘mean') to aggregate nearest neighbours’ imputed values.

Value

List containing imputed values from each assay_list data matrix which contains reference cells.

Examples

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# stabMap
out <- stabMap(assay_list,
  ncomponentsReference = 20,
  ncomponentsSubset = 20
)

# impute values
imp <- imputeEmbedding(assay_list, out)

# inspect the imputed values
lapply(imp, dim)
imp[[1]][1:5, 1:5]

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# stabMap
out <- stabMap(assay_list,
  ncomponentsReference = 20,
  ncomponentsSubset = 20
)

# impute values
imp <- imputeEmbedding(assay_list, out)

# inspect the imputed values
lapply(imp, dim)
imp[[1]][1:5, 1:5]

mockMosaicData

Description

Mock up a mosaic data list using simulated data, for use in documentation examples.

Usage

mockMosaicData(
  names = c("D1", "D2", "D3"),
  ncells = c(50, 50, 50),
  ngenes = list(1:150, 76:225, 151:300),
  fun = "rnorm",
  ...
)
mockMosaicData(
  names = c("D1", "D2", "D3"),
  ncells = c(50, 50, 50),
  ngenes = list(1:150, 76:225, 151:300),
  fun = "rnorm",
  ...
)

Arguments

`names`	character vector of mock datasets.
`ncells`	integer vector of cells in each mock dataset.
`ngenes`	list containing integer vectors of features measured in each mock dataset.
`fun`	name of function to simulate data, default "rnorm".
`...`	further arguments passed to 'fun'.

Value

assay_list a list of data matrices with rownames (features) specified.

Examples

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# simulate data from another distribution
assay_list <- mockMosaicData(fun = "rnbinom", size = 5, prob = 0.5)
lapply(assay_list, dim)

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# simulate data from another distribution
assay_list <- mockMosaicData(fun = "rnbinom", size = 5, prob = 0.5)
lapply(assay_list, dim)

mosaicDataTopology

Description

Generate mosaic data topology network as an igraph object.

Usage

mosaicDataTopology(assay_list)
mosaicDataTopology(assay_list)

Arguments

assay_list

a list of data matrices with rownames (features) specified.

Value

igraph weighted network with nodes corresponding to assay_list elements, and edges present if the matrices share at least one rowname. Edge weights correspond to the number of shared rownames among data matrices.

Examples

set.seed(2021)
assay_list <- mockMosaicData()
mdt <- mosaicDataTopology(assay_list)
mdt
plot(mdt)

set.seed(2021)
assay_list <- mockMosaicData()
mdt <- mosaicDataTopology(assay_list)
mdt
plot(mdt)

mosaicDataUpSet

Description

Plots feature overlaps of mosaic data as an UpSet plot.

Usage

mosaicDataUpSet(assay_list, plot = FALSE, ...)
mosaicDataUpSet(assay_list, plot = FALSE, ...)

Arguments

`assay_list`	a list of data matrices with rownames (features) specified.
`plot`	logical (default FALSE) whether the UpSet plot should be printed.
`...`	further arguments passed to 'upset' from the 'UpSetR' package.

Value

UpSet object displaying degree of overlap of rownames (features) among each of the data matrices in assay_list. Set bars correspond to the number of cells/samples present in each data matrix.

Examples

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)
mosaicDataUpSet(assay_list)

# additional arguments from UpSetR::upset()
mosaicDataUpSet(assay_list, empty.intersections = TRUE)

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)
mosaicDataUpSet(assay_list)

# additional arguments from UpSetR::upset()
mosaicDataUpSet(assay_list, empty.intersections = TRUE)

Re-weight StabMap embedding

Description

Re-weights embedding according to given weights for each reference dataset. This gives more or less weighting to each contributing dataset and method (PCA or LDA),

Usage

reWeightEmbedding(embedding, weights = NULL, factor = 1e+06)
reWeightEmbedding(embedding, weights = NULL, factor = 1e+06)

Arguments

`embedding`	Joint embedding as output from stabMap.
`weights`	(optional) named numeric vector giving relative weights for each reference dataset.
`factor`	numeric multiplicative value to offset near-zero values.

Value

matrix of same dimensions as 'embedding'.

Examples

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# specify which datasets to use as reference coordinates
reference_list <- c("D1", "D3")

# specify some sample labels to distinguish using linear discriminant
# analysis (LDA)
labels_list <- list(
  D1 = rep(letters[1:5], length.out = ncol(assay_list[["D1"]]))
)

# stabMap
out <- stabMap(assay_list,
  reference_list = reference_list,
  labels_list = labels_list,
  ncomponentsReference = 20,
  ncomponentsSubset = 20
)

# look at the scale of each component and discriminant
boxplot(out, las = 2, outline = FALSE)

# re-weight embedding for less contribution from LDs and equal contribution
# from PCs of both references
out_reweighted <- reWeightEmbedding(
  out,
  weights = c("D1_LD" = 0.5, "D1_PC" = 1, "D3_PC" = 1)
)

# look at the new scale of each component and discriminant
boxplot(out_reweighted, las = 2, outline = FALSE)

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# specify which datasets to use as reference coordinates
reference_list <- c("D1", "D3")

# specify some sample labels to distinguish using linear discriminant
# analysis (LDA)
labels_list <- list(
  D1 = rep(letters[1:5], length.out = ncol(assay_list[["D1"]]))
)

# stabMap
out <- stabMap(assay_list,
  reference_list = reference_list,
  labels_list = labels_list,
  ncomponentsReference = 20,
  ncomponentsSubset = 20
)

# look at the scale of each component and discriminant
boxplot(out, las = 2, outline = FALSE)

# re-weight embedding for less contribution from LDs and equal contribution
# from PCs of both references
out_reweighted <- reWeightEmbedding(
  out,
  weights = c("D1_LD" = 0.5, "D1_PC" = 1, "D3_PC" = 1)
)

# look at the new scale of each component and discriminant
boxplot(out_reweighted, las = 2, outline = FALSE)

Stabilised mosaic single cell data integration using unshared features

Description

stabMap performs mosaic data integration by first building a mosaic data topology, and for each reference dataset, traverses the topology to project and predict data onto a common principal component (PC) or linear discriminant (LD) embedding.

Usage

stabMap(
  assay_list,
  labels_list = NULL,
  reference_list = NULL,
  reference_features_list = lapply(assay_list, rownames),
  reference_scores_list = NULL,
  ncomponentsReference = 50,
  ncomponentsSubset = 50,
  suppressMessages = TRUE,
  projectAll = FALSE,
  restrictFeatures = FALSE,
  maxFeatures = 1000,
  plot = TRUE,
  scale.center = TRUE,
  scale.scale = TRUE,
  SE_assay_names = "logcounts",
  BPPARAM = SerialParam(),
  verbose = TRUE
)
stabMap(
  assay_list,
  labels_list = NULL,
  reference_list = NULL,
  reference_features_list = lapply(assay_list, rownames),
  reference_scores_list = NULL,
  ncomponentsReference = 50,
  ncomponentsSubset = 50,
  suppressMessages = TRUE,
  projectAll = FALSE,
  restrictFeatures = FALSE,
  maxFeatures = 1000,
  plot = TRUE,
  scale.center = TRUE,
  scale.scale = TRUE,
  SE_assay_names = "logcounts",
  BPPARAM = SerialParam(),
  verbose = TRUE
)

Arguments

`assay_list`	A list of data matrices with rownames (features) specified.
`labels_list`	(optional) named list containing cell labels
`reference_list`	Named list containing logical values whether the data matrix should be considered as a reference dataset, alternatively a character vector containing the names of the reference data matrices. If NULL, defaults to: sapply(names(assay_list), function(x) TRUE, simplify = FALSE)
`reference_features_list`	List of features to consider as reference data (default is all available features).
`reference_scores_list`	Named list of reference scores (default NULL). If provided, matrix of cells (rows with rownames given) and dimensions (columns with colnames given) are used as the reference low-dimensional embedding to target, as opposed to performing PCA or LDA on the input reference data.
`ncomponentsReference`	Number of principal components for embedding reference data, given either as an integer or a named list for each reference dataset.
`ncomponentsSubset`	Number of principal components for embedding query data prior to projecting to the reference, given either as an integer or a named list for each reference dataset.
`suppressMessages`	Logical whether to suppress messages (default TRUE).
`projectAll`	Logical whether to re-project reference data along with query (default FALSE).
`restrictFeatures`	logical whether to restrict to features used in dimensionality reduction of reference data (default FALSE). Overall it's recommended that this be FALSE for single-hop integrations and TRUE for multi-hop integrations.
`maxFeatures`	Maximum number of features to consider for predicting principal component scores (default 1000).
`plot`	Logical whether to plot mosaic data UpSet plot and mosaic data topology networks (default TRUE).
`scale.center`	Logical whether to re-center data to a mean of 0 (default FALSE).
`scale.scale`	Logical whether to re-scale data to standard deviation of 1 (default FALSE).
`SE_assay_names`	Either a string indicating the name of the assays for the SummarizedExperiment objects in assay_list or a named list of assay names, where the names corrispond to the names SE objects in assay_list (default "logcounts")
`BPPARAM`	a BiocParallelParam object specifying how parallelisation should be performed
`verbose`	Logical whether console output is provided (default TRUE)

Value

matrix containing common embedding with rows corresponding to cells, and columns corresponding to PCs or LDs for reference dataset(s).

Examples

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# specify which datasets to use as reference coordinates
reference_list <- c("D1", "D3")

# specify some sample labels to distinguish using linear discriminant
# analysis (LDA)
labels_list <- list(
  D1 = rep(letters[1:5], length.out = ncol(assay_list[["D1"]]))
)

# examine the topology of this mosaic data integration
mosaicDataUpSet(assay_list)
plot(mosaicDataTopology(assay_list))

# stabMap
out <- stabMap(assay_list,
  reference_list = reference_list,
  labels_list = labels_list,
  ncomponentsReference = 20,
  ncomponentsSubset = 20
)

head(out)

set.seed(2021)
assay_list <- mockMosaicData()
lapply(assay_list, dim)

# specify which datasets to use as reference coordinates
reference_list <- c("D1", "D3")

# specify some sample labels to distinguish using linear discriminant
# analysis (LDA)
labels_list <- list(
  D1 = rep(letters[1:5], length.out = ncol(assay_list[["D1"]]))
)

# examine the topology of this mosaic data integration
mosaicDataUpSet(assay_list)
plot(mosaicDataTopology(assay_list))

# stabMap
out <- stabMap(assay_list,
  reference_list = reference_list,
  labels_list = labels_list,
  ncomponentsReference = 20,
  ncomponentsSubset = 20
)

head(out)

Package 'StabMap'

Help Index

Adaptive k-Nearest Neighbour Classification

Description

Usage

Arguments

Value

Examples

Adaptive k-Nearest Neighbour Classification using the StabMap joint embedding

Description

Usage

Arguments

Value

Examples

Adaptive k selection for KNN classification

Description

Usage

Arguments

Value

Examples

Impute values using StabMap joint embedding

Description

Usage

Arguments

Value

Examples

mockMosaicData

Description

Usage

Arguments

Value

Examples

mosaicDataTopology

Description

Usage

Arguments

Value

Examples

mosaicDataUpSet

Description

Usage

Arguments

Value

Examples

Re-weight StabMap embedding

Description

Usage

Arguments

Value

Examples

Stabilised mosaic single cell data integration using unshared features

Description

Usage

Arguments

Value

Examples