matlab_class/sample_processing/example_griddata.m

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

%%%%%%%%%%%%%%%%%
%load grid:
%%%%%%%%%%%%%%%%%

p = genpath('gcmfaces/'); addpath(p);
p = genpath('MITprof/'); addpath(p);

gcmfaces_global;

mygrid=[]; grid_load;

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

%%%%%%%%%%%%%%%%%%%%%%%
%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	1.14	%%%%%%%%%%%%%%%%%
5			%load grid:
6			%%%%%%%%%%%%%%%%%
7
8			p = genpath('gcmfaces/'); addpath(p);
9			p = genpath('MITprof/'); addpath(p);
10
11	gforget	1.11	gcmfaces_global;
12	gforget	1.14
13			mygrid=[]; grid_load;
14
15	gforget	1.11	if myenv.verbose>0;
16			gcmfaces_msg('===============================================');
17			gcmfaces_msg(['*** entering example_griddata that will define ' ...
18	gforget	1.14	'a 2x2 gridded variable (an bathymetry field here), and then ' ...
19	gforget	1.11	'use griddata to map it to the chosen grid. '],'');
20			end;
21
22	gforget	1.1	%%%%%%%%%%%%%%%%%%%%%%%
23	gforget	1.12	%get sample data: subsampled mygrid.Depth
24	gforget	1.11	if myenv.verbose>0;
25	gforget	1.12	gcmfaces_msg('* define test case : subsampled bathymetry');
26	gforget	1.11	end;
27	gforget	1.12	original_Depth=mygrid.Depth;
28			original_Depth(original_Depth==0)=NaN;
29			lon=mygrid.XC; lat=mygrid.YC;
30			for ff=1:mygrid.nFaces;
31			lon{ff}(1:2:end,:)=NaN;
32			lat{ff}(1:2:end,:)=NaN;
33			original_Depth{ff}(1:2:end,:)=NaN;
34			lon{ff}(:,1:2:end)=NaN;
35			lat{ff}(:,1:2:end)=NaN;
36			original_Depth{ff}(:,1:2:end)=NaN;
37			end;
38			lon=convert2vector(lon);
39			lat=convert2vector(lat);
40			vec=convert2vector(original_Depth);
41	gforget	1.1
42			%%%%%%%%%%%%%%%%%%%%%%%
43	gforget	1.11	%make sure to accomodate the two longitude conventions:
44			if myenv.verbose>0;
45			gcmfaces_msg('* accomodate both lon. conventions, then convert to data vector');
46			end;
47	gforget	1.12	x=[lon-360;lon;lon+360]; y=[lat;lat;lat]; z=[vec;vec;vec];
48	gforget	1.1	jj=find(~isnan(z)); x=x(jj); y=y(jj); z=z(jj);
49
50	gforget	1.11	%%%%%%%%%%%%%%%%%%%%%%%
51			%do the interpolation:
52			if myenv.verbose>0;
53			gcmfaces_msg('* map/interpolate data using griddata');
54			end;
55	gforget	1.12	griddata_Depth=gcmfaces(5);
56	gforget	1.8	for ii=1:mygrid.nFaces;
57	gforget	1.12	xi=mygrid.XC{ii}; yi=mygrid.YC{ii};
58			zi = griddata(x',y',z',xi,yi);
59			griddata_Depth{ii}=zi;
60	gforget	1.1	end;
61
62	gforget	1.12	%msk=mygrid.hFacC(:,:,1); griddata_Depth(find(msk==0))=NaN;
63	gforget	1.1
64			%%%%%%%%%%%%%%%%%%%%%%%
65			%illustrate the result:
66
67	gforget	1.12	figureL;
68			subplot(2,1,1); set(gca,'FontSize',14);
69			[X,Y,FLD]=convert2pcol(mygrid.XC,mygrid.YC,original_Depth);
70			pcolor(X,Y,FLD); axis([-180 180 -90 90]); shading flat;
71			title('input to griddata');
72			subplot(2,1,2); set(gca,'FontSize',14);
73			[X,Y,FLD]=convert2pcol(mygrid.XC,mygrid.YC,griddata_Depth);
74			pcolor(X,Y,FLD); axis([-180 180 -90 90]); shading flat;
75			title('output of griddata');
76	gforget	1.1
77	gforget	1.11	if myenv.verbose>0;
78			gcmfaces_msg('* note of caution : griddata puts values on land. ');
79			gcmfaces_msg('*** leaving example_griddata');
80			gcmfaces_msg('===============================================');
81			end;