Re: [R] counting the number of rows that satisfy a certain criteria

Hi, Try: set.seed(42)  X <- as.data.frame(matrix(sample(0:1, 4*50,replace=TRUE), ncol=4))  table(X[1:2])[4] #[1] 15 sum(rowSums(X[1:2])==2) #[1] 15 A.K. On Saturday, June 21, 2014 10:59 AM, Kate Ignatius wrote: I have 4 columns, and about 300K plus rows with 0s and 1s. I'm trying to count h

Re: [R] counting the number of rows that satisfy a certain criteria

Thanks! On Sat, Jun 21, 2014 at 11:05 AM, Jorge I Velez wrote: > Hi Kate, > > You could try > > sum(X[, 1] == 1 & X[, 2] == 1) > > where X is your data set. > > HTH, > Jorge.- > > > > On Sun, Jun 22, 2014 at 12:57 AM, Kate Ignatius > wrote: >> >> I have 4 columns, and about 300K plus rows with

Re: [R] counting the number of rows that satisfy a certain criteria

Hi Kate, You could try sum(X[, 1] == 1 & X[, 2] == 1) where X is your data set. HTH, Jorge.- On Sun, Jun 22, 2014 at 12:57 AM, Kate Ignatius wrote: > I have 4 columns, and about 300K plus rows with 0s and 1s. > > I'm trying to count how many rows satisfy a certain criteria... for > instan

[R] counting the number of rows that satisfy a certain criteria

I have 4 columns, and about 300K plus rows with 0s and 1s. I'm trying to count how many rows satisfy a certain criteria... for instance, how many rows are there that have the first column == 1 as well as the second column == 1. I've tried using rowSums and colSums but it keeps giving me this type