matlab_class/gcmfaces_misc/annualmean.m

function [myMean,myAnom]=annualmean(myTimes,myFld,myYear);
%object: compute an annual mean for myYear (= 'first','last',n (int) or 'all')
%        of a gcmfaces or array object (myFld) provided at myTimes (in years)
%input:  myTimes,myFld,myYear
%output: myMean if the corresponding time mean
%       (optional: myAnom is myFld-myMean)
%
%algorithm :
%  - determine the number of records in one year (lYear)
%  - determine the number of full years (nYears)
%  - prepare list of records to average (depending on myYear, lYear and nYears)
%  - in case when lYear<2 we use records as years
%
%by assumption: 
%  - the time dimension is last in myFld, and matches the length of myTimes

%determine the number of records in one year (lYear)
tmp1=mean(myTimes(2:end)-myTimes(1:end-1));
lYear=round(1/tmp1);

%in case when lYear<2 we use records as years
if ~(lYear>=2); lYear=1; myTimes=[1:length(myTimes)]; end;

%determine the number of full years (nYears)
nYears=floor(length(myTimes)/lYear);

%determine records that correspond to myYear, which
%  may be 'first','last',n (an integer) or 'all'
if ischar(myYear);
  if strcmp(myYear,'first');
    recInAve=[1:lYear];
  elseif strcmp(myYear,'last');
    recInAve=[1:lYear]+(nYears-1)*lYear;
  elseif strcmp(myYear,'all');
    recInAve=[1:nYears*lYear];
  else;
    error('inconsistent specification of myYear');
  end;
elseif (myYear>=1)&(myYear<=nYears);
  recInAve=[1:lYear]+(myYear-1)*lYear;
else;
  error('inconsistent specification of myYear');
end;
nRecs=length(recInAve);

%determine last dimension, which need to match the length myTimes
if strcmp(class(myFld),'gcmfaces'); nDim=size(myFld{1}); else; nDim=size(myFld); end;
if nDim(end)~=length(myTimes); error('last dimensopn should match the length of myTimes'); end;
nDim=length(nDim); tt=''; for jj=1:nDim-1; tt=[tt ':,']; end;

%compute time mean:
eval(['myMean=mean(myFld(' tt 'recInAve),nDim);']);

%compute anomaly:
if nargout>1; 
myAnom=myFld-repmat(myMean,[ones(1:nDim-1) length(myTimes)]); 
end;

1	function [myMean,myAnom]=annualmean(myTimes,myFld,myYear);
2	%object: compute an annual mean for myYear (= 'first','last',n (int) or 'all')
3	% of a gcmfaces or array object (myFld) provided at myTimes (in years)
4	%input: myTimes,myFld,myYear
5	%output: myMean if the corresponding time mean
6	% (optional: myAnom is myFld-myMean)
7	%
8	%algorithm :
9	% - determine the number of records in one year (lYear)
10	% - determine the number of full years (nYears)
11	% - prepare list of records to average (depending on myYear, lYear and nYears)
12	% - in case when lYear<2 we use records as years
13	%
14	%by assumption:
15	% - the time dimension is last in myFld, and matches the length of myTimes
16
17	%determine the number of records in one year (lYear)
18	tmp1=mean(myTimes(2:end)-myTimes(1:end-1));
19	lYear=round(1/tmp1);
20
21	%in case when lYear<2 we use records as years
22	if ~(lYear>=2); lYear=1; myTimes=[1:length(myTimes)]; end;
23
24	%determine the number of full years (nYears)
25	nYears=floor(length(myTimes)/lYear);
26
27	%determine records that correspond to myYear, which
28	% may be 'first','last',n (an integer) or 'all'
29	if ischar(myYear);
30	if strcmp(myYear,'first');
31	recInAve=[1:lYear];
32	elseif strcmp(myYear,'last');
33	recInAve=[1:lYear]+(nYears-1)*lYear;
34	elseif strcmp(myYear,'all');
35	recInAve=[1:nYears*lYear];
36	else;
37	error('inconsistent specification of myYear');
38	end;
39	elseif (myYear>=1)&(myYear<=nYears);
40	recInAve=[1:lYear]+(myYear-1)*lYear;
41	else;
42	error('inconsistent specification of myYear');
43	end;
44	nRecs=length(recInAve);
45
46	%determine last dimension, which need to match the length myTimes
47	if strcmp(class(myFld),'gcmfaces'); nDim=size(myFld{1}); else; nDim=size(myFld); end;
48	if nDim(end)~=length(myTimes); error('last dimensopn should match the length of myTimes'); end;
49	nDim=length(nDim); tt=''; for jj=1:nDim-1; tt=[tt ':,']; end;
50
51	%compute time mean:
52	eval(['myMean=mean(myFld(' tt 'recInAve),nDim);']);
53
54	%compute anomaly:
55	if nargout>1;
56	myAnom=myFld-repmat(myMean,[ones(1:nDim-1) length(myTimes)]);
57	end;
58