search for: pcttest

...d how to do this in base R, but I'd be surprised if it's not possible. I'm just trying to replace multiple columns at once in a data frame. #load example data data(api) #this displays the three columns and eight rows i'd like to replace apiclus1[ apiclus1$meals > 98 , c( "pcttest" , "api00" , "sch.wide" ) ] #the goal is to replace pcttest with 100, api100 with NA, and sch.wide with "Maybe" #this doesn't work-- apiclus1[ apiclus1$meals > 98 , c( "pcttest" , "api00" , "sch.wide" ) ] <- c( 100 , NA ,...