[R] data manipulation help

[Dieter Menne]

roberto munguia <munguiar <at> posgrado.ecologia.edu.mx> writes:

> 
> I have a dataframe with 468 individuals (rows) that I captured at least once
> during 28 visits (columns), it looks like:
> 
> mortality[1:10,]
> 
> 
> 1            1           0           0           0           1           1
> 1           0           0           0
..
> so I can know how many times every individual was captured, 0= not capture,
> 1=capture. 
 
> I also want to know when  was the first and the last capture for every
> individual,

This should give you a starter

# create play data
cap = data.frame(matrix(rbinom(120,1,0.3),nrow=10))

firstthat<-function(x) which(x)[1] # stolen from Thomas Lumley

# Make your data logical; not really needed, but easier to understand
cap.log = cap==1
apply(cap.log,1,firstthat) # gives first captures

Dieter