Filter data.frame rows by a logical condition

Question

I want to filter rows from a data.frame based on a logical condition. Let\'s suppose that I have data frame like

   expr_value     cell_type
1           


        

Answer 1

You could use the dplyr package:

library(dplyr)
filter(expr, cell_type == "hesc")
filter(expr, cell_type == "hesc" | cell_type == "bj fibroblast")