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Author SHA1 Message Date
MarijnBerg 55b27c57a6 Swapped base R plots for ggplot 2021-11-01 14:42:49 +01:00
MarijnBerg a620b4e5d2 Fixed bug that caused incompatibility with biobase due to having the same function name.
Added new profiling functions.
2021-11-01 14:25:43 +01:00
MarijnBerg 0427dcc6ad Removed uniused variable 2021-10-05 15:00:42 +02:00
1 changed files with 116 additions and 18 deletions

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@ -13,6 +13,9 @@
library(Matrix)
library(Seurat)
library(qlcMatrix)
library(pheatmap)
library(ggplot2)
library(gridExtra)
###############################################################################
@ -46,12 +49,11 @@ remove.background = function(geneCellMatrix, ambientRNAprofile){
}
##############
determine.background.to.remove = function(fullCellMatrix, cellMatrix, emptyDropletCutoff, contaminationChanceCutoff){
determine.background.to.remove = function(fullCellMatrix, emptyDropletCutoff, contaminationChanceCutoff){
# determines the highest expression value found for every gene in the droplets that we're sure don't contain cells
backGroundMax = as.vector(rowMax(fullCellMatrix[,Matrix::colSums(fullCellMatrix) < emptyDropletCutoff]))
backGroundMax = as.vector(qlcMatrix::rowMax(fullCellMatrix[,Matrix::colSums(fullCellMatrix) < emptyDropletCutoff]))
names(backGroundMax) = rownames(fullCellMatrix)
nCell = ncol(cellMatrix)
# droplets that are empty but not unused barcodes, unused barcodes have zero reads assigned to them.
nEmpty = table((Matrix::colSums(fullCellMatrix) < emptyDropletCutoff) &(Matrix::colSums(fullCellMatrix) > 0))[2]
@ -80,6 +82,93 @@ read.full.matrix = function(fullFolderLocation){
return(fullMatrix)
}
###############################################################################
getExpressionThreshold = function(gene, expMat, percentile){
orderedExpression = expMat[gene, order(expMat[gene,], decreasing = TRUE)]
CS = cumsum(orderedExpression)
return(orderedExpression[which(CS/max(CS) > percentile)[1]])
}
###############################################################################
celltypeSpecificityScore = function(gene, expMat){
CS = cumsum(expMat[gene, order(expMat[gene,], decreasing = TRUE)])
return((sum(CS/max(CS))/ncol(expMat)) )
}
###############################################################################
describe.correction.effect = function (allExpression, cellExpression, startPos, stopPos, byLength, contaminationChanceCutoff){
# Make somewhere to store all the data that needs to be returned to the user
ambientScoreProfileOverview = data.frame(row.names = rownames(cellExpression))
# do a quick first run to see which genes get corrected at the highest setting
ambientProfile = determine.background.to.remove(allExpression, cellExpression, stopPos, contaminationChanceCutoff)
genelist = names(ambientProfile[ambientProfile > 0])
print(paste0("Calculating cell expression score for ", length(genelist), " genes"))
ctsScores = vector(mode = "numeric", length = nrow(cellExpression))
names(ctsScores) = rownames(cellExpression)
for(gene in genelist){
ctsScores[gene] = celltypeSpecificityScore(gene, cellExpression)
}
# loop over every threshold to test
# Starts at the highest value so
for(emptyDropletCutoff in seq(from = startPos, to = stopPos, by = byLength)){
ambientProfile = determine.background.to.remove(allExpression, cellExpression, emptyDropletCutoff, contaminationChanceCutoff)
print(paste0("Profiling at cutoff ", emptyDropletCutoff))
ambientScoreProfile = data.frame(ambientProfile, ctsScores)
#ambientScoreProfile = ambientScoreProfile[ambientScoreProfile$ctsScores > 0.85, ]
ambientScoreProfile$stillOverAmbient = 0
ambientScoreProfile$belowCellexpression = 0
genesToCheck = names(ambientProfile[ambientProfile > 0])
if(exists("overAmbientGenes")){
genesToCheck = overAmbientGenes
}
print(paste0("Calculating profiles for ", length(genesToCheck), " genes"))
for(gene in genesToCheck){
expThresh = getExpressionThreshold(gene, cellExpression, 0.95)
if(emptyDropletCutoff == startPos){
ambientScoreProfile[gene, "belowCellexpression"] = table(cellExpression[gene,] > 0 & cellExpression[gene,] < expThresh)["TRUE"]
}
ambientScoreProfile[gene, "stillOverAmbient"] = table(cellExpression[gene,] > ambientScoreProfile[gene, "ambientProfile"] & cellExpression[gene,] < expThresh)["TRUE"]
}
ambientScoreProfile[is.na(ambientScoreProfile)] = 0
ambientScoreProfile$contaminationChance = ambientScoreProfile$stillOverAmbient / ambientScoreProfile$belowCellexpression
ambientScoreProfile[is.na(ambientScoreProfile)] = 0
# Genes that have already been completely removed don't need to be checked at higher resolution
overAmbientGenes = rownames(ambientScoreProfile[ambientScoreProfile$stillOverAmbient > 0,])
ambientScoreProfile[genelist,"AmbientCorrection"]
ambientScoreProfileOverview[names(ctsScores), "ctsScores"] = ctsScores
if(emptyDropletCutoff == startPos){
ambientScoreProfileOverview[rownames(ambientScoreProfile), "belowCellexpression"] = ambientScoreProfile$belowCellexpression
}
ambientScoreProfileOverview[rownames(ambientScoreProfile), paste0("stillOverAmbient", as.character(emptyDropletCutoff))] = ambientScoreProfile$stillOverAmbient
ambientScoreProfileOverview[rownames(ambientScoreProfile), paste0("AmbientCorrection", as.character(emptyDropletCutoff))] = ambientScoreProfile$ambientProfile
}
ambientScoreProfileOverview = ambientScoreProfileOverview[!is.na(ambientScoreProfileOverview$ctsScores),]
ambientScoreProfileOverview[is.na(ambientScoreProfileOverview)] = 0
ambientScoreProfileOverview[,paste0("Threshold_", seq(from = startPos, to = stopPos, by = byLength))] = ambientScoreProfileOverview[,paste0("stillOverAmbient", as.character(seq(from = startPos, to = stopPos, by = byLength)))] / ambientScoreProfileOverview$belowCellexpression
ambientScoreProfileOverview[is.na(ambientScoreProfileOverview)] = 0
ambientScoreProfileOverview[,paste0("contaminationChance", as.character(seq(from = startPos, to = stopPos, by = byLength)))] = ambientScoreProfileOverview[,paste0("stillOverAmbient", as.character(seq(from = startPos, to = stopPos, by = byLength)))] / ambientScoreProfileOverview$belowCellexpression
return(ambientScoreProfileOverview)
}
##############
# Turns out that cellranger output looks different from WriteMM output and Read10X can't read the latter
# TODO
@ -100,14 +189,15 @@ read.full.matrix = function(fullFolderLocation){
# }
# describe the number of genes identified in the background
# and the number of genes failing the contaminiation chance threshold
# and the number of genes failing the contamination chance threshold
#
describe.ambient.RNA.sequence = function(fullCellMatrix, start, stop, by, contaminationChanceCutoff){
cutoffValue = seq(start, stop, by)
genesInBackground = vector(mode = "numeric", length = length(seq(start, stop, by)))
genesContaminating = vector(mode = "numeric", length = length(seq(start, stop, by)))
nEmptyDroplets = vector(mode = "numeric", length = length(seq(start, stop, by)))
ambientDescriptions = data.frame(nEmptyDroplets, genesInBackground, genesContaminating)
ambientDescriptions = data.frame(nEmptyDroplets, genesInBackground, genesContaminating, cutoffValue)
rownames(ambientDescriptions) = seq(start, stop, by)
for(emptyCutoff in seq(start, stop, by)){
nEmpty = table((Matrix::colSums(fullCellMatrix) < emptyCutoff) &(Matrix::colSums(fullCellMatrix) > 0))[2]
@ -125,23 +215,31 @@ describe.ambient.RNA.sequence = function(fullCellMatrix, start, stop, by, contam
}
plot.correction.effect.chance = function(correctionProfile){
pheatmap(correctionProfile[correctionProfile[,3] > 0, colnames(correctionProfile)[grep("contaminationChance", colnames(correctionProfile))]],
cluster_cols = FALSE,
treeheight_row = 0,
main = "Chance of affecting DE analyses")
}
plot.correction.effect.removal = function(correctionProfile){
pheatmap(correctionProfile[(correctionProfile[,3] > 0) ,colnames(correctionProfile)[grep("AmbientCorrection", colnames(correctionProfile))]],
cluster_cols = FALSE, treeheight_row = 0,
main = "Counts removed from each cell")
}
plot.ambient.profile = function(ambientProfile){
par(mfrow = c(3,1))
plot(as.numeric(rownames(ambientProfile)), ambientProfile[,1],
main = "Total number of empty droplets at cutoffs",
xlab = "empty droplet UMI cutoff",
ylab = "Number of empty droplets")
plot(as.numeric(rownames(ambientProfile)), ambientProfile[,2],
main = "Number of genes in ambient RNA",
xlab = "empty droplet UMI cutoff",
ylab = "Genes in empty droplets")
p1 = ggplot(ambientProfile, aes(x=cutoffValue, y=genesInBackground)) + geom_point()
p2= ggplot(ambientProfile, aes(x=cutoffValue, y=genesContaminating)) + geom_point()
p3 = ggplot(ambientProfile, aes(x=cutoffValue, y=nEmptyDroplets)) + geom_point()
grid.arrange(p1, p2, p3, nrow = 3)
plot(as.numeric(rownames(ambientProfile)), ambientProfile[,3],
main = "number of genes to correct",
xlab = "empty droplet UMI cutoff",
ylab = "Genes identified as contamination")
}
# I noticed that the number of genes removed tends to even out over time