Return the relationship of samples acorrding from the gene expression values. Click Here to see an example figure. PCA wikipedia
The PCA will be accomplished by R using library 'gmodels'
The expression matrix file must contain row and column names and separated by Tabs, generally the row names are the unigene IDs and the column names are the sample names, displayed as follow.
GeneID sample1 sample2 sample3 sample4
Unigene00001 1300.99 1665.09 1352.56 1121.33
Unigene00002 3454.18 355.8 440.78 2260.36
Unigene00003 1873.72 551.4 1529.66 519.94 ...