matlab_class/sample_processing/example_griddata.m

function []=example_griddata();
%object:    a griddata example within gcmfaces

gcmfaces_global;
if myenv.verbose>0;
    gcmfaces_msg('===============================================');
    gcmfaces_msg(['*** entering example_griddata that will define ' ...
        'a 2x2 gridded variable (an SSH field here), and then ' ...
        'use griddata to map it to the chosen grid. '],'');
end;

%%%%%%%%%%%%%%%%%
%load parameters:
%%%%%%%%%%%%%%%%%

gcmfaces_global;
nF=5;
fileFormat='compact';
dirGrid=fullfile(myenv.gcmfaces_dir,'..',filesep,'GRID',filesep);

mygrid=[]; grid_load(dirGrid,nF,fileFormat,1);

%%%%%%%%%%%%%%%%%%%%%%%
%get sample data: subsampled mygrid.Depth
if myenv.verbose>0;
    gcmfaces_msg('* define test case : subsampled bathymetry');
end;
original_Depth=mygrid.Depth;
original_Depth(original_Depth==0)=NaN;
lon=mygrid.XC; lat=mygrid.YC;
for ff=1:mygrid.nFaces;
    lon{ff}(1:2:end,:)=NaN;
    lat{ff}(1:2:end,:)=NaN;
    original_Depth{ff}(1:2:end,:)=NaN;
    lon{ff}(:,1:2:end)=NaN;
    lat{ff}(:,1:2:end)=NaN;
    original_Depth{ff}(:,1:2:end)=NaN;
end;
lon=convert2vector(lon);
lat=convert2vector(lat);
vec=convert2vector(original_Depth);

%%%%%%%%%%%%%%%%%%%%%%%
%make sure to accomodate the two longitude conventions:
if myenv.verbose>0;
    gcmfaces_msg('* accomodate both lon. conventions, then convert to data vector');
end;
x=[lon-360;lon;lon+360]; y=[lat;lat;lat]; z=[vec;vec;vec];
jj=find(~isnan(z)); x=x(jj); y=y(jj); z=z(jj);

%%%%%%%%%%%%%%%%%%%%%%%
%do the interpolation:
if myenv.verbose>0;
    gcmfaces_msg('* map/interpolate data using griddata');
end;
griddata_Depth=gcmfaces(5);
for ii=1:mygrid.nFaces;
    xi=mygrid.XC{ii}; yi=mygrid.YC{ii};
    zi = griddata(x',y',z',xi,yi);
    griddata_Depth{ii}=zi;
end;

%msk=mygrid.hFacC(:,:,1); griddata_Depth(find(msk==0))=NaN;

%%%%%%%%%%%%%%%%%%%%%%%
%illustrate the result:

figureL;
subplot(2,1,1); set(gca,'FontSize',14);
[X,Y,FLD]=convert2pcol(mygrid.XC,mygrid.YC,original_Depth);
pcolor(X,Y,FLD); axis([-180 180 -90 90]); shading flat;
title('input to griddata');
subplot(2,1,2); set(gca,'FontSize',14);
[X,Y,FLD]=convert2pcol(mygrid.XC,mygrid.YC,griddata_Depth);
pcolor(X,Y,FLD); axis([-180 180 -90 90]); shading flat;
title('output of griddata');

if myenv.verbose>0;
    gcmfaces_msg('* note of caution : griddata puts values on land. ');
    gcmfaces_msg('*** leaving example_griddata');
    gcmfaces_msg('===============================================');
end;
1	gforget	1.13	function []=example_griddata();
2	gforget	1.8	%object: a griddata example within gcmfaces
3	gforget	1.1
4	gforget	1.11	gcmfaces_global;
5			if myenv.verbose>0;
6			gcmfaces_msg('===============================================');
7			gcmfaces_msg(['*** entering example_griddata that will define ' ...
8			'a 2x2 gridded variable (an SSH field here), and then ' ...
9			'use griddata to map it to the chosen grid. '],'');
10			end;
11
12	gforget	1.1	%%%%%%%%%%%%%%%%%
13			%load parameters:
14			%%%%%%%%%%%%%%%%%
15	gforget	1.12
16			gcmfaces_global;
17	gforget	1.13	nF=5;
18			fileFormat='compact';
19			dirGrid=fullfile(myenv.gcmfaces_dir,'..',filesep,'GRID',filesep);
20	gforget	1.12
21			mygrid=[]; grid_load(dirGrid,nF,fileFormat,1);
22	gforget	1.1
23			%%%%%%%%%%%%%%%%%%%%%%%
24	gforget	1.12	%get sample data: subsampled mygrid.Depth
25	gforget	1.11	if myenv.verbose>0;
26	gforget	1.12	gcmfaces_msg('* define test case : subsampled bathymetry');
27	gforget	1.11	end;
28	gforget	1.12	original_Depth=mygrid.Depth;
29			original_Depth(original_Depth==0)=NaN;
30			lon=mygrid.XC; lat=mygrid.YC;
31			for ff=1:mygrid.nFaces;
32			lon{ff}(1:2:end,:)=NaN;
33			lat{ff}(1:2:end,:)=NaN;
34			original_Depth{ff}(1:2:end,:)=NaN;
35			lon{ff}(:,1:2:end)=NaN;
36			lat{ff}(:,1:2:end)=NaN;
37			original_Depth{ff}(:,1:2:end)=NaN;
38			end;
39			lon=convert2vector(lon);
40			lat=convert2vector(lat);
41			vec=convert2vector(original_Depth);
42	gforget	1.1
43			%%%%%%%%%%%%%%%%%%%%%%%
44	gforget	1.11	%make sure to accomodate the two longitude conventions:
45			if myenv.verbose>0;
46			gcmfaces_msg('* accomodate both lon. conventions, then convert to data vector');
47			end;
48	gforget	1.12	x=[lon-360;lon;lon+360]; y=[lat;lat;lat]; z=[vec;vec;vec];
49	gforget	1.1	jj=find(~isnan(z)); x=x(jj); y=y(jj); z=z(jj);
50
51	gforget	1.11	%%%%%%%%%%%%%%%%%%%%%%%
52			%do the interpolation:
53			if myenv.verbose>0;
54			gcmfaces_msg('* map/interpolate data using griddata');
55			end;
56	gforget	1.12	griddata_Depth=gcmfaces(5);
57	gforget	1.8	for ii=1:mygrid.nFaces;
58	gforget	1.12	xi=mygrid.XC{ii}; yi=mygrid.YC{ii};
59			zi = griddata(x',y',z',xi,yi);
60			griddata_Depth{ii}=zi;
61	gforget	1.1	end;
62
63	gforget	1.12	%msk=mygrid.hFacC(:,:,1); griddata_Depth(find(msk==0))=NaN;
64	gforget	1.1
65			%%%%%%%%%%%%%%%%%%%%%%%
66			%illustrate the result:
67
68	gforget	1.12	figureL;
69			subplot(2,1,1); set(gca,'FontSize',14);
70			[X,Y,FLD]=convert2pcol(mygrid.XC,mygrid.YC,original_Depth);
71			pcolor(X,Y,FLD); axis([-180 180 -90 90]); shading flat;
72			title('input to griddata');
73			subplot(2,1,2); set(gca,'FontSize',14);
74			[X,Y,FLD]=convert2pcol(mygrid.XC,mygrid.YC,griddata_Depth);
75			pcolor(X,Y,FLD); axis([-180 180 -90 90]); shading flat;
76			title('output of griddata');
77	gforget	1.1
78	gforget	1.11	if myenv.verbose>0;
79			gcmfaces_msg('* note of caution : griddata puts values on land. ');
80			gcmfaces_msg('*** leaving example_griddata');
81			gcmfaces_msg('===============================================');
82			end;