[R] using mapply()

[dxc13]

useR's,

This is a follow up question to one I previously asked.  Consider the
3-element list below

> res
[[1]]
       [,1] [,2]  [,3]  [,4]  [,5] [,6]  [,7] [,8]  [,9] [,10] [,11] [,12]
[,13] [,14]
[1,]   NA   NA   NA 1.25 0.25 0.75   NA   NA   NA    NA    NA    NA  1.25 
0.25
[2,] 1.25 0.25 0.75   NA   NA   NA   NA   NA   NA  1.25  0.25  0.75    NA   
NA
[3,]   NA   NA   NA   NA   NA   NA 1.25 0.25 0.75    NA    NA    NA    NA   
NA
[4,]   NA   NA 1.25 0.25 0.75   NA   NA   NA   NA    NA    NA  1.25  0.25 
0.75
[5,]   NA   NA   NA   NA   NA 1.25 0.25 0.75   NA    NA    NA    NA    NA   
NA

[[2]]
       [,1] [,2]  [,3] [,4]  [,5] [,6]  [,7]  [,8] [,9] [,10] [,11] [,12]
[,13] [,14]
[1,]   NA   NA   NA   NA   NA   NA   NA   NA   NA    NA    NA    NA    NA   
1.25
[2,] 1.25   NA   NA   NA   NA   NA   NA   NA   NA    NA    NA    NA    NA   
NA
[3,] 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25  0.25  0.25  0.25  0.25 
0.25
[4,]   NA   NA   NA   NA   NA   NA   NA   NA   NA    NA    NA    NA    NA   
NA
[5,]   NA   NA   NA   NA   NA  1.25   NA   NA   NA    NA    NA    NA    NA   
NA

[[3]]
       [,1] [,2]  [,3]  [,4] [,5] [,6]  [,7]  [,8] [,9] [,10] [,11] [,12]
[,13]  [,14]
[1,]   NA   NA   NA   NA   NA   NA   NA   NA   NA    NA    NA    NA    NA   
1.25
[2,] 0.25   NA   NA   NA   NA   NA   NA   NA   NA    NA    NA    NA    NA   
NA
[3,] 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25  0.25  0.25  0.25  0.25 
0.25
[4,]   NA   NA   NA   NA   NA   NA   NA   NA   NA    NA    NA    NA    NA   
NA
[5,]   NA   NA   NA   NA   NA  0.25   NA   NA   NA    NA    NA    NA    NA   
NA

What I want to do is find the values that are not NA simultaneously for each
value in each element of the list, and then average these numbers and store
them in a 14x1 vector.  For example, in position (2,1) in each of the 3
elements of the res list, there is a value, 1.25 in [[1]] and [[2]], 0.25 in
[[3]].  Since there is a value in this position in all elements of the list
I want to average these numbers: (1.25+1.25+0.25)/3 and store this value in
a numeric vector.   So, if there are not 3 values to average, this means
that a given position (i,j) does not have a value in each element of the
list and thus I want to store NA in the 14x1 vector.  In the end, the 14x1
vector will be mixed with values and NA's or NaN's.

Does anyone know a efficient way to do this?  Maybe using mapply()?  I hope
it is clear.  Thank you for any input.

Derek
-- 
View this message in context: http://www.nabble.com/using-mapply%28%29-tp14697351p14697351.html
Sent from the R help mailing list archive at Nabble.com.