[R] How to skip negative values when calculating average

2010-05-31 Thread ecvetano
I have a data frame 10 by 12 with positive and negative numbers. I want to select only the positive numbers and find the average. This calculates the average of everything: av5 - subset(ER9r, Day == 253, select = c (Depth1j:Depth0.75j) av5 - mean(av5) I need something along the lines of

Re: [R] How to skip negative values when calculating average

2010-05-31 Thread David Winsemius
On May 31, 2010, at 2:06 PM, ecvet...@uwaterloo.ca wrote: I have a data frame 10 by 12 with positive and negative numbers. I want to select only the positive numbers and find the average. This calculates the average of everything: av5 - subset(ER9r, Day == 253, select = c