Off topic:How to link non-unique colnames in two different files ?

Question

[Björn]

I have a file1 with example col names as follows xyz-123 xyz-234 abc-345 abc-789. Another file2 with row names xyz abc. How to link file2 and file1 using row names of file2. Please note xyz-123 xyz-234 have different information from same patient. I need to link those files and process into edgeR. File1 is rna sequencing data while file2 is patient metadata. Thanks