%This example code illustrates how to access and visualize LaRC_MOPITT Grid file in Matlab. 
%If you have any questions, suggestions, comments  on this example, please use the HDF-EOS Forum (http://hdfeos.org/forums). 
%If you would like to see an  example of any other NASA HDF/HDF-EOS data product that is not listed in the HDF-EOS Comprehensive Examples page (http://hdfeos.org/zoo), 
%feel free to contact us at eoshelp@hdfgroup.org or post it at the HDF-EOS Forum (http://hdfeos.org/forums).

clear
%Opening the HDF-EOS2 Grid File
FILE_NAME='MOP03-20000303-L3V1.0.1.hdf';
file_id = hdfgd('open', FILE_NAME, 'rdonly');

%Reading Data from a Data Field
GRID_NAME='MOP03';
grid_id = hdfgd('attach', file_id, GRID_NAME);

DATAFIELD_NAME='CO Profiles Day';

[data1, fail] = hdfgd('readfield', grid_id, DATAFIELD_NAME, [], [], []);
%Read lat and lon. It provides GeoLatitude and GeoLongitude in the
%datafield of group1.
[lat, fail] = hdfgd('readfield', grid_id, 'Latitude', [], [], []);
[lon, fail] = hdfgd('readfield', grid_id, 'Longitude', [], [], []);

%Convert M-D data to 2-D data
data=squeeze(data1(7,:,:));

%Transpose the data to match the map projection
data=data';

%Convert the data to double type for plot
data=double(data);
lat=double(lat);
lon=double(lon);

%Detaching from the Grid Object
hdfgd('detach', grid_id);
%Closing the File
hdfgd('close', file_id);

%Replacing the filled value with NaN
data(data==-9999) = NaN;

%Plot the data using contourfm and axesm
latlim=[floor(min(min(lat))),ceil(max(max(lat)))];
lonlim=[floor(min(min(lon))),ceil(max(max(lon)))];
min_data=floor(min(min(data)));
max_data=ceil(max(max(data)));


figure('Name','MOP03-20000303-L3V1.0.1_CO_Profiles_Day_nprs6')

axesm('MapProjection','eqdcylin','Frame','on','Grid','on', 'MapLatLimit',latlim,'MapLonLimit',lonlim, ...
    'MeridianLabel','on','ParallelLabel','on')
coast = load('coast.mat');

contourfm(lat,lon,data);
colormap('Jet');
caxis([min_data max_data]); 
colorbar('YTick', min_data:20:max_data);

plotm(coast.lat,coast.long,'k')

title({'MOP03-20000303-L3V1.0.1\_CO\_Profiles\_Day' ; 'at nprs=6'},'FontSize',16,'FontWeight','bold');