examples/biplot-examples.R

In mixOmicsTeam/mixOmics: Omics Data Integration Project

## 'pca' class - examples demonstrate how to control sample colours and customise plots
# -------------------------------------------------------------------------------------
set.seed(42)
data("nutrimouse")
pca.lipid <- pca(nutrimouse$lipid, ncomp = 3, scale = TRUE)

# colors indicate diet
biplot(pca.lipid, group = nutrimouse$diet)

# colors indicate genotype
biplot(pca.lipid, group = nutrimouse$genotype)

# customise colours
biplot(pca.lipid, group = nutrimouse$genotype,
       col = c("red", "blue"))

## correlation cutoff to filter features
biplot(pca.lipid, cutoff = c(0.8))

## tailor threshold for each component
biplot(pca.lipid, cutoff = c(0.8, 0.7))

## customise components
biplot(pca.lipid, cutoff = c(0.8), comp = c(1,3))

## customise ggplot in an arbitrary way
biplot(pca.lipid) + theme_linedraw() + 
    # add vline
    geom_vline(xintercept = 0, col = 'green') +
    # add hline
    geom_hline(yintercept = 0, col = 'green') +
    # customise labs
    labs(x = 'Principal Component 1', y = 'Principal Component 2')

## customise variable labels
biplot(pca.lipid, 
       var.names.col = color.mixo(2),
       var.names.size = 4,
       var.names.angle = TRUE
)

## no arrows
biplot(pca.lipid, group = nutrimouse$diet, legend.title = 'Diet', 
       var.arrow.col = NULL, var.names.col = 'black')

## add x=0 and y=0 lines in function
biplot(pca.lipid, group = nutrimouse$diet, legend.title = 'Diet', 
       var.arrow.col = NULL, var.names.col = 'black', 
       vline = TRUE, hline = TRUE)

## 'pls' class - examples demonstrate how to control cutoffs
# -------------------------------------------------------------------------------------

data("nutrimouse")
pls.nutrimouse <- pls(X = nutrimouse$gene, Y = nutrimouse$lipid, ncomp = 2)

biplot(pls.nutrimouse, group = nutrimouse$genotype, block = 'X',
       legend.title = 'Genotype', cutoff = 0.878) 

biplot(pls.nutrimouse, group = nutrimouse$genotype, block = 'Y',
       legend.title = 'Genotype', cutoff = 0.8) 


## 'plsda' class - examples demonstrate how to control point shapes
# -------------------------------------------------------------------------------------

data(breast.tumors)
X <- breast.tumors$gene.exp
colnames(X) <- paste0('GENE_', colnames(X))
rownames(X) <- paste0('SAMPLE_', rownames(X))
Y <- breast.tumors$sample$treatment
nrow(X)
grouping <- factor(c(rep("A", 20), rep("B", 20), rep("C", 7)))

plsda.breast <- plsda(X, Y, ncomp = 2)

biplot(plsda.breast, cutoff = 0.72, ind.names = FALSE)

biplot(plsda.breast, cutoff = 0.72, ind.names = FALSE, pch = 2, pch.size = 5)

biplot(plsda.breast, cutoff = 0.72, pch = grouping, pch.size = 5)