Displaying 1 result from an estimated 1 matches for "tp4650646p4650803".
2012 Nov 24
2
Performing operations only on selected data
I spent some time on this simple question, also searched the forum,
eventually hacked my way to an ugly solution for my particular problem but I
would like to improve my coding:
I have data of the form:
df <- expand.grid(group=c('copper', 'zinc', 'aluminum', 'nickel'),
condition1=c(1:4))
I would like to add a new data column "condition2", with values