/[MITgcm]/MITgcm_contrib/gael/matlab_class/gcmfaces_misc/runmean.m
ViewVC logotype

Diff of /MITgcm_contrib/gael/matlab_class/gcmfaces_misc/runmean.m

Parent Directory Parent Directory | Revision Log Revision Log | View Revision Graph Revision Graph | View Patch Patch

revision 1.1 by gforget, Fri Mar 26 20:18:33 2010 UTC revision 1.3 by gforget, Fri Jul 8 12:58:14 2011 UTC
# Line 1  Line 1 
1  %this function does a running mean along dimension dim_cur,  function [fldOut]=runmean(fldIn,halfWindow,dim,varargin);
2  %averaging over indices [-nb_cur:nb_cur]  %object:    compute running mean window ('rmw') over a dimension
3    %input:     fldIn is the field to which the rmw will be applied
4    %           halfWindow is the half width of the rmw
5    %           dim is the dimension over which the rmw will be applied
6    %optional:  doCycle states whether the boundary condition is cyclic (1) or
7    %               not (0; default). If doCycle==0, the no. of averaged points
8    %               decreases from 1+2*halfWindow to halfWindow at the edges.
9    %output:    fldOut is the resulting field
10  %  %
11  function [field_out]=runmean(field_in,nb_cur,dim_cur);  %notes:     - NaNs are discarded in the rmw, implying that an average is
12    %           computed if the rmw contains at least 1 valid point.
13    %           - setting halfWindow to 0 implies fldOut=fldIn.
14    
15    %determine and check a couple things
16    fld_isa_gcmfaces=isa(fldIn,'gcmfaces');
17    if fld_isa_gcmfaces;
18        if dim<3;
19            error('for gcmfaces objects runmean excludes dim=1 or 2');
20        end;
21    end;
22    
23    if nargin==3; doCycle=0; else; doCycle=varargin{1}; end;
24    
25    %switch to array format if needed
26    if fld_isa_gcmfaces; fldOut=convert2array(fldOut); end;
27    
28    %switch dim to first dimension
29    sizeIn=size(fldIn);
30    
31    perm1to2=[1:length(sizeIn)];
32    perm1to2=[dim perm1to2(find(perm1to2~=dim))];
33    perm2to1=[[1:dim-1]+1 1 [dim+1:length(sizeIn)]];
34    sizeIn2=sizeIn(perm1to2);
35    
36    fldIn=permute(fldIn,perm1to2);
37    
38    sizeCur=size(fldIn);
39    if ~doCycle;
40        %add NaNs at both edges
41        sizeCur(1)=sizeCur(1)+2*halfWindow;
42        fldIn2=NaN*ones(sizeCur);
43        fldIn2(halfWindow+1:end-halfWindow,:,:,:)=fldIn;
44        fldIn=fldIn2; clear fldIn2;
45    end;
46    
47    %create mask and remove NaNs:
48    fldMsk=~isnan(fldIn);
49    fldIn(isnan(fldIn))=0;
50    fldCnt=0*fldIn;
51    
52    %apply the running mean
53    fldOut=zeros(sizeCur);
54    for tcur=-halfWindow:halfWindow
55        %To have halfWindow*2 coeffs rather than halfWindow*2+1, centered to the current
56        %point, it is convenient to reduce the weight of the farthest points to 1/2.
57        %This became necessary to get proper annual means, from monthly data, with halfWindow=6.
58        if abs(tcur)==halfWindow; fac=1/2; else; fac=1; end;
59        tmp1=circshift(fldIn,[tcur zeros(1,length(sizeCur)-1)]);
60        fldOut=fldOut+fac*tmp1;
61        tmp1=circshift(fldMsk,[tcur zeros(1,length(sizeCur)-1)]);
62        fldCnt=fldCnt+fac*tmp1;
63    end
64    
65  if nb_cur~=0  fldCnt(fldCnt==0)=NaN;
66    fldOut=fldOut./fldCnt;
67    
68  size_cur=size(field_in);  if ~doCycle;
69        fldOut=fldOut(halfWindow+1:end-halfWindow,:,:,:);
70        %consistent with old version bug (one point offset)
71        %     fldOut=fldOut(halfWindow:end-halfWindow,:,:,:);
72    end;
73    
74  perm1to2=[1:length(size_cur)];  %switch dimensions order back to original order
75  perm1to2=[dim_cur perm1to2(find(perm1to2~=dim_cur))];  fldOut=permute(fldOut,perm2to1);
 perm2to1=[[1:dim_cur-1]+1 1 [dim_cur+1:length(size_cur)]];  
 size_cur2=size_cur(perm1to2);  
   
 field_in2=permute(field_in,perm1to2);  
   
 field_out2=zeros(size_cur2);  
 count_out2=zeros(size_cur2(1),2);  
 for tcur=-nb_cur:nb_cur  
         tmp1=[tcur:tcur-1+size_cur2(1)];  
         tmp2=find(tmp1>=1&tmp1<=size_cur2(1));  
         field_out2(tmp2,:)=field_out2(tmp2,:)+field_in2(tmp1(tmp2),:);  
         count_out2(tmp2,:)=count_out2(tmp2,:)+1;  
 end  
 for tcur=1:size_cur2(1);  
         field_out2(tcur,:)=field_out2(tcur,:)/count_out2(tcur);  
 end  
76    
77  %field_out=field_in-permute(field_out2,perm2to1);  %switch back to gcmfaces format if needed
78  field_out=permute(field_out2,perm2to1);  if fld_isa_gcmfaces; fldOut=convert2array(fldOut); end;
79    
 else  
 field_out=field_in;  
 end%if nb_cur~=0  
80    
81    

Legend:
Removed from v.1.1  
changed lines
  Added in v.1.3

  ViewVC Help
Powered by ViewVC 1.1.22