tests/testthat/test.markerDiffTable.R

In monocle: Clustering, differential expression, and trajectory analysis for single- cell RNA-Seq

library(monocle)
library(HSMMSingleCell)
context("markerDiffTable is functioning properly")

data(HSMM_expr_matrix)
data(HSMM_gene_annotation)
data(HSMM_sample_sheet)

pd <- new("AnnotatedDataFrame", data = HSMM_sample_sheet)
fd <- new("AnnotatedDataFrame", data = HSMM_gene_annotation)

# First create a CellDataSet from the relative expression levels
HSMM <- newCellDataSet(as.matrix(HSMM_expr_matrix),   
                       phenoData = pd, 
                       featureData = fd,
                       lowerDetectionLimit=0.1,
                       expressionFamily=tobit(Lower=0.1))

# Next, use it to estimate RNA counts
rpc_matrix <- relative2abs(HSMM, method = "num_genes")

# Now, make a new CellDataSet using the RNA counts
HSMM <- newCellDataSet(as(as.matrix(rpc_matrix), "sparseMatrix"),
                       phenoData = pd, 
                       featureData = fd,
                       lowerDetectionLimit=0.5,
                       expressionFamily=negbinomial.size())

HSMM <- estimateSizeFactors(HSMM)
HSMM <- estimateDispersions(HSMM)

HSMM <- detectGenes(HSMM, min_expr = 0.1)
expressed_genes <- row.names(subset(fData(HSMM), num_cells_expressed >= 10))

pData(HSMM)$Total_mRNAs <- Matrix::colSums(exprs(HSMM))

HSMM <- HSMM[,pData(HSMM)$Total_mRNAs < 1e6]

HSMM <- detectGenes(HSMM, min_expr = 0.1)

# Log-transform each value in the expression matrix.
L <- log(exprs(HSMM[expressed_genes,]))

# Standardize each gene, so that they are all on the same scale,
# Then melt the data with plyr so we can plot it easily
melted_dens_df <- melt(Matrix::t(scale(Matrix::t(L))))

# Plot the distribution of the standardized gene expression values.
qplot(value, geom = "density", data = melted_dens_df) +
  stat_function(fun = dnorm, size = 0.5, color = 'red') +
  xlab("Standardized log(FPKM)") +
  ylab("Density")

MYF5_id <- row.names(subset(fData(HSMM), gene_short_name == "MYF5"))
ANPEP_id <- row.names(subset(fData(HSMM), gene_short_name == "ANPEP"))

cth <- newCellTypeHierarchy()
cth <- addCellType(cth, "Myoblast", classify_func = function(x) { x[MYF5_id,] >= 1 })
cth <- addCellType(cth, "Fibroblast", classify_func = function(x)
{ x[MYF5_id,] < 1 & x[ANPEP_id,] > 1 })

HSMM <- classifyCells(HSMM, cth, 0.1)

test_that("markerDiffTable works properly in vignette", 
          expect_error(markerDiffTable(HSMM[expressed_genes,],
                                       cth,
                                       residualModelFormulaStr = "~Media + num_genes_expressed",
                                       cores = 1), NA))

test_that("markerDiffTable works when 'balanced set to true'", 
          expect_error(markerDiffTable(HSMM[expressed_genes,],
                                       cth,
                                       balanced = TRUE,
                                       residualModelFormulaStr = "~Media + num_genes_expressed",
                                       cores = 1), NA))

test_that("markerDiffTable works when 'verbose set to true'", 
          expect_error(markerDiffTable(HSMM[expressed_genes,],
                                       cth,
                                       verbose = TRUE,
                                       residualModelFormulaStr = "~Media + num_genes_expressed",
                                       cores = 1), NA))

test_that("markerDiffTable throws error if cds is not of type 'CellDataSet'", 
          expect_error(markerDiffTable(cth,
                                       cth,
                                       balanced = TRUE,
                                       residualModelFormulaStr = "~Media + num_genes_expressed",
                                       cores = 1), "Error cds is not of type 'CellDataSet'"))

test_that("markerDiffTable throws error if cds is not of type 'CellDataSet'", 
          expect_error(markerDiffTable(HSMM[expressed_genes,],
                                       HSMM[expressed_genes],
                                       balanced = TRUE,
                                       residualModelFormulaStr = "~Media + num_genes_expressed",
                                       cores = 1), "Error cth is not of type 'CellTypeHierarchy'"))