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

Sometimes the column you want to filter may appear in a different position than column index 2 or have a variable name.

In this case, you can simply refer the column name you want to filter as:

columnNameToFilter = "cell_type"
expr[expr[[columnNameToFilter]] == "hesc", ]