[R] (no subject)

[Andy Bunn]

Look at ?Extract

myDF <- data.frame(c1 = c(1,1,1,1,2,2,2,2), 
                   c2 = c(23,34,45,45,78,65,45,70),
                   c3 = c(12,15,67,87,23,19,90,32))
mean(myDF[myDF$c2 == 45,3])


HTH, Andy