I have a huge data file; a sample is listed below. I am using the package data table to process the file and I am stuck on one issue and need some feedback. I used fread to create a data table. Then I divided the data table (named File1) into 10 general subsets using common table commands such as:
AAA <- File1[Num<5&day>15] BBB <- File1[Num>15&day<10] ….. ….. ….. ….. ….. ….. I wanted to divide and count each of the above subsets based on a set of parameters common to all subsets. I did the following to go through each subset and it works: For (I in 1: length (AAA)) { aa <- c(AAA[color==”green”&grade==”a”,month==”Januray” .N],[ AAA[color==”green”&grade==”b”& month==”June”’ .N]) } The question: I don’t want to have a separate loop for each subset (10 loops). Instead, I was hoping to have 2 nested loops in the form below: For (I in 1:N)){ For (j in 1:M){ } } Sample Num Color Grade Value Month Day 1 yellow A 20 May 1 2 green B 25 June 2 3 green A 10 April 3 4 black A 17 August 3 5 red C 5 December 5 6 orange D 0 January 13 7 orange E 12 January 5 8 orange F 11 February 8 9 orange F 99 July 23 10 orange F 70 May 7 11 black A 77 June 11 12 green B 87 April 33 13 black A 79 August 9 14 green A 68 December 14 15 black C 90 January 31 16 green D 79 January 11 17 black E 101 February 17 18 red F 90 July 21 19 red F 112 February 13 20 red F 101 July 20 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.