Check sources of variation
Next you need to use principal components analysis to check for the sources of variation in the data. Do the samples cluster by their genotype (WT vs. Top2b null) and treatment (PBS vs. Dox)?
Cet exercice fait partie du cours
Differential Expression Analysis with limma in R
Instructions
The ExpressionSet object eset
with the doxorubicin data has been loaded in your workspace. The limma package is already loaded.
Use
plotMDS
to plot the principal components. Label the samples by their genotype.Re-visualize the principal components, labeling the samples by their treatment.
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Plot principal components labeled by genotype
___(eset, labels = ___(eset)[___], gene.selection = "common")
# Plot principal components labeled by treatment
___(eset, labels = ___(eset)[___], gene.selection = "common")