Off topic:Extracting rows in r by their number

Question

[jivarajivaraj]

Hi,

I have a matrix in R, columns are my samples and rows my genes; I want to extract some genes by their position in rowslike genes 100, 876, 438, and 997 other genes.

I read these number as a vector but I don't know how to intersect as rownames of my matrix is genes rather the number

How I can do that please?

Thanks