[R] error in rowSums in data.table

2013-05-30 Thread Camilo Mora
hi: I have a datatable with two columns (see below) and I want to create another column that adds the values of the rows in the first two columns. I am trying this: DT[ , col3 :=rowSums(.SD, na.rm = TRUE), .SDcols = c(col1,col2)] but I get this error: Error in inherits(x, data.frame) :

Re: [R] error in rowSums in data.table

2013-05-30 Thread Rainer Schuermann
On Thursday 30 May 2013 02:57:04 Camilo Mora wrote: do you know why is this? or is there another way to sum by row in a given number of columns? Without data.table: x - structure(list(col1 = c(NA, 0, -0.015038, 0.003817, -0.011407 ), col2 = c(0.003745, 0.007463, -0.007407, -0.003731,