Newer
Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
function y = nanmean(x,dim)
% FORMAT: Y = NANMEAN(X,DIM)
%
% Average or mean value ignoring NaNs
%
% This function enhances the functionality of NANMEAN as distributed in
% the MATLAB Statistics Toolbox and is meant as a replacement (hence the
% identical name).
%
% NANMEAN(X,DIM) calculates the mean along any dimension of the N-D
% array X ignoring NaNs. If DIM is omitted NANMEAN averages along the
% first non-singleton dimension of X.
%
% Similar replacements exist for NANSTD, NANMEDIAN, NANMIN, NANMAX, and
% NANSUM which are all part of the NaN-suite.
%
% See also MEAN
% -------------------------------------------------------------------------
% author: Jan Gläscher
% affiliation: Neuroimage Nord, University of Hamburg, Germany
% email: glaescher@uke.uni-hamburg.de
%
% $Revision: 1.1 $ $Date: 2004/07/15 22:42:13 $
if isempty(x)
y = NaN;
return
end
if nargin < 2
dim = min(find(size(x)~=1));
if isempty(dim)
dim = 1;
end
end
% Replace NaNs with zeros.
nans = isnan(x);
x(isnan(x)) = 0;
% denominator
count = size(x,dim) - sum(nans,dim);
% Protect against a all NaNs in one dimension
i = find(count==0);
count(i) = ones(size(i));
y = sum(x,dim)./count;
y(i) = i + NaN;
% $Id: nanmean.m,v 1.1 2004/07/15 22:42:13 glaescher Exp glaescher $