Message-ID: <f8fcbc833e3e1.3e3e1f8fcbc83@student.uva.nl>
Date: 2009-03-20T00:25:12Z
From: T.R. Marshall
Subject: Mean-replacing NAs in a 3d array
Hi all
I have a 3d array containing missing values.
> Xa
, , 1
[,1] [,2]
[1,] 1 3
[2,] NA 4
, , 2
[,1] [,2]
[1,] 5 7
[2,] NA NA
, , 3
[,1] [,2]
[1,] 9 11
[2,] 10 12
I want to replace the missing values with the mean, but the mean of each
'page' in the array (wrong terminology I'm sure). So - for the array
above - [2,1,2] and [2,2,2] should both read '6', and [2,1,1] should be
'2.66667'.
I can obtain a vector of those means by:
> colMeans(Xa,na.rm=TRUE,dims=2)
[1] 2.666667 6.000000 10.500000
But what to do next?
Help would be appreciated. Also I'm a noob to this mailing list so
apologies if I've not given enough detail or failed to find the answer
somewhere obvious.
Best
Tom Marshall, Universiteit van Amsterdam