data visualization RNAseq : scaling data for PCA and cluster dendogram
Scaling (or centering) makes the genes comparable: Putting the expression levels of genes in the same scale (i.e. between 0 and 1) sustains that all of your genes contribute equally to the PCA or distance calculations. On the other hand, without this step, such calculations would be dominated by the highly/lowly expressed genes. I get &quot;better&quot; results with scaling.