R help - Jul 2012 - integrating multi-dimensional dat along one dimension

I just want to integrate a 3D data set along one dimension to obtain a
2D data set.  Something like:

 

(given array "d" with dim nx,ny,nz ...)

 

data_int<-array(dim=c(nx,ny))

for (n in 1:ny) {

  for (m in 1:nx) {

     data_int[m,n]<-sum(d[m,n,])

  }

}

 

The thing is, given R's facility with integers, it seems that I should
be able to obtain data_int without the explicit for-loops, but I haven't
been able to figure out how to do it.  Anyone know how?  Thanks.


	[[alternative HTML version deleted]]

set.seed(42)
d <- array(as.integer(round(runif(125)*10, 0)), dim=c(5, 5, 5))
data_int <- apply(d, c(1,2), sum)

-------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77840-4352


----- Original Message ----- 

From: "Sam B Civ USAF AFMC AFRL Cable/RVBXI" <Sam.Cable at
kirtland.af.mil>
To: r-help at r-project.org 
Sent: Friday, July 13, 2012 4:11:28 PM 
Subject: [R] integrating multi-dimensional dat along one dimension 

I just want to integrate a 3D data set along one dimension to obtain a 
2D data set. Something like: 



(given array "d" with dim nx,ny,nz ...) 



data_int<-array(dim=c(nx,ny)) 

for (n in 1:ny) { 

for (m in 1:nx) { 

data_int[m,n]<-sum(d[m,n,]) 

} 

} 



The thing is, given R's facility with integers, it seems that I should 
be able to obtain data_int without the explicit for-loops, but I haven't 
been able to figure out how to do it. Anyone know how? Thanks. 


[[alternative HTML version deleted]] 

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