Count based on 2 conditions [Beginner Question]
On Sep 16, 2012, at 3:41 AM, SirRon wrote:
Hello,
I'm working with a dataset that has 2 columns and 1000 entries. Column 1 has
either value 0 or 1, column 2 has values between 0 and 10. I would like to
count how often Column 1 has the value 1, while Column 2 has a value greater
5.
This is my attempt, which works but doesn't seem to be very efficient,
especially when testing different values or columns.
count=0
for (i in 1:1000) { if(dataset[i,2]>5 && ind[i,1]==1) { count=count+1}}
I'm looking for a more efficient/elegant way to do this!
I see others have given you a solution using the vectorized sum function. I would have reached for 'table' and done it thusly: table( one=dataset[,1], GT5=dataset[ , 2] > 5 )
David Winsemius, MD Alameda, CA, USA