I need to extract many columns from a dataset. I have a very large csv file with thousands of columns and rows. In R for example, I can read it in using:
mydata <- read.csv(file = "file.csv",header = TRUE,sep = ",",row.names = 1)
Each column is a gene name. I know how to extract specific columns from my R data.frame by using the basic code like this:
mydata[ , "GeneName1", "GeneName2"]
But my question is, how do I pull hundreds of gene names? Too many to type in? They are listed in a txt file.
I've used grep in UNIX before to pull multiple ROWS using a txt file with the list of genes I need, but I haven't been able to figure out how to do it with Columns.