208    ◾    Bioinformatics

data = yNorm,

type = ‘edger’,

d.factor = NULL,

title = TRUE, grid = TRUE)

dev.off()

5.3.8.3  Mean-Average Plot (MA Plot)

The “vsMAPlot()” function graphs the log-fold change versus the mean count to visualize

the variance between the two conditions in terms of gene expression values.

jpeg(‘MAPlot.jpg’)

vsMAPlot(

x = ‘norm’, y = ‘tumo’,

data = yNorm,

d.factor = NULL,

FIGURE 5.33  Volcano plot showing differential gene expression.