netcdf_matlab_examples/latlon_2d/EH3_notes_latlon_2d.txt

%
%  Ed Hill
%  Fri Dec 12 12:09:00 EST 2003

%  Test Ingrid's ability to handle 2D lat-lon grids

matlab -nojvm
  clear all

  theta = 15 * pi/180;
  rot = [ -sin(theta) cos(theta) ; cos(theta) sin(theta) ];
  nx = 11;  lats = [ -30 30 ];
  ny = 21;  lons = [ -30 30 ];
  lat = zeros(nx,ny);
  lon = zeros(nx,ny);
  val = zeros(nx,ny);
  for i = 1:nx,
    for j = 1:ny,
      p(1) = lons(1) + (i-1)*(lons(2)-lons(1))/(nx-1);
      p(2) = lats(1) + (j-1)*(lats(2)-lats(1))/(ny-1);
      pr = rot * p';
      lat(i,j) = pr(1);
      lon(i,j) = pr(2);
      val(i,j) = norm(pr);
    end
  end

  mesh(lat,lon,val), view(2), axis equal
  surf(lat,lon,val), view(2), axis equal, shading interp

  idv = 'concentration';
  idlat = 'lat';
  idlon = 'lon';
  units = 'g/m^3';

  desc = [ 'Test of 2D lat-lon grids in Ingrid.' ];
  ncname = [ 'test_2d.nc' ];
  nc = netcdf(ncname, 'clobber');
  nc.reference = desc;
  nc.author = 'Ed Hill <eh3@mit.edu>';
  nc.date = 'Dec 30, 2003';
  nc('X') = nx;
  nc('Y') = ny;
  nc{'X'} = 'X';
  nc{'Y'} = 'Y';
  nc{ idlon } = { 'Y', 'X' };
  nc{ idlat } = { 'Y', 'X' };
  nc{ idv } = { 'Y', 'X' };
  nc{'X'}.uniquename = 'X';
  nc{'Y'}.uniquename = 'Y';
  nc{ idlon }.units = 'degree_east';
  nc{ idlon }.long_name = 'longitude';
  nc{ idlat }.units = 'degree_north';
  nc{ idlat }.long_name = 'latitude';
  nc{ idv }.units = units;
  nc{ idv }.coordinates = 'lat lon';
  nc{ idv }.long_name = idv;
  nc{ idv }.missing_value = ncdouble(NaN);
  nc{ idv }.FillValue_ = ncdouble(0.);
  nc{'X'}(:) = [1:nx];
  nc{'Y'}(:) = [1:ny];
  nc{ idlon }(:) = lon';
  nc{ idlat }(:) = lat';
  nc{ idv }(:) = val';
  nc = close(nc);

  ! scp ./test_2d.nc channel.mit.edu:/home/edhill/test_2d/
  
% as edhill on channel.mit.edu :
  mkdir test_2d

% AS ROOT ON channel.mit.edu :
  cd /home/benno/ingrid/data/MIT/LOCAL/PEOPLE/EH3
  mkdir test_2d
  cd test_2d
  ln -s /home/edhill/test_2d/* .


% ;;; Local Variables: ***
% ;;; mode:matlab ***
% ;;; End: ***
1	%
2	% Ed Hill
3	% Fri Dec 12 12:09:00 EST 2003
4
5	% Test Ingrid's ability to handle 2D lat-lon grids
6
7	matlab -nojvm
8	clear all
9
10	theta = 15 * pi/180;
11	rot = [ -sin(theta) cos(theta) ; cos(theta) sin(theta) ];
12	nx = 11; lats = [ -30 30 ];
13	ny = 21; lons = [ -30 30 ];
14	lat = zeros(nx,ny);
15	lon = zeros(nx,ny);
16	val = zeros(nx,ny);
17	for i = 1:nx,
18	for j = 1:ny,
19	p(1) = lons(1) + (i-1)*(lons(2)-lons(1))/(nx-1);
20	p(2) = lats(1) + (j-1)*(lats(2)-lats(1))/(ny-1);
21	pr = rot * p';
22	lat(i,j) = pr(1);
23	lon(i,j) = pr(2);
24	val(i,j) = norm(pr);
25	end
26	end
27
28	mesh(lat,lon,val), view(2), axis equal
29	surf(lat,lon,val), view(2), axis equal, shading interp
30
31	idv = 'concentration';
32	idlat = 'lat';
33	idlon = 'lon';
34	units = 'g/m^3';
35
36	desc = [ 'Test of 2D lat-lon grids in Ingrid.' ];
37	ncname = [ 'test_2d.nc' ];
38	nc = netcdf(ncname, 'clobber');
39	nc.reference = desc;
40	nc.author = 'Ed Hill <eh3@mit.edu>';
41	nc.date = 'Dec 30, 2003';
42	nc('X') = nx;
43	nc('Y') = ny;
44	nc{'X'} = 'X';
45	nc{'Y'} = 'Y';
46	nc{ idlon } = { 'Y', 'X' };
47	nc{ idlat } = { 'Y', 'X' };
48	nc{ idv } = { 'Y', 'X' };
49	nc{'X'}.uniquename = 'X';
50	nc{'Y'}.uniquename = 'Y';
51	nc{ idlon }.units = 'degree_east';
52	nc{ idlon }.long_name = 'longitude';
53	nc{ idlat }.units = 'degree_north';
54	nc{ idlat }.long_name = 'latitude';
55	nc{ idv }.units = units;
56	nc{ idv }.coordinates = 'lat lon';
57	nc{ idv }.long_name = idv;
58	nc{ idv }.missing_value = ncdouble(NaN);
59	nc{ idv }.FillValue_ = ncdouble(0.);
60	nc{'X'}(:) = [1:nx];
61	nc{'Y'}(:) = [1:ny];
62	nc{ idlon }(:) = lon';
63	nc{ idlat }(:) = lat';
64	nc{ idv }(:) = val';
65	nc = close(nc);
66
67	! scp ./test_2d.nc channel.mit.edu:/home/edhill/test_2d/
68
69	% as edhill on channel.mit.edu :
70	mkdir test_2d
71
72	% AS ROOT ON channel.mit.edu :
73	cd /home/benno/ingrid/data/MIT/LOCAL/PEOPLE/EH3
74	mkdir test_2d
75	cd test_2d
76	ln -s /home/edhill/test_2d/* .
77
78
79
80	% ;;; Local Variables: ***
81	% ;;; mode:matlab ***
82	% ;;; End: ***