Design matrix for group-means model
In the previous chapter, you tested the leukemia data for differential expression using the traditional treatment-contrasts parametrization. As a first step to learning the more flexible group-means parametrization, you will re-test the leukemia data to confirm you obtain the same results.
Este exercício faz parte do curso
Differential Expression Analysis with limma in R
Instruções do exercício
The ExpressionSet object eset
with the leukemia data has been loaded in your workspace.
- Use
model.matrix
to create a design matrix with no intercept. Recall that the variable of interest for this study (progressive vs. stable cancers) is in the columnDisease
of the phenotype data frame.
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
# Create design matrix with no intercept
design <- ___(~___ + ___, data = ___(eset))
# Count the number of samples modeled by each coefficient
colSums(design)