Example 4.1. Pathfinder with Loaddap

>> pathfinder_loaddap
url = 'http://data.nodc.noaa.gov/cgi-bin/nph-dods/pathfinder/Version5.0_Climatologies/Daily/Day/day001_day.hdf';
%
% Retrieve all the metadata using loaddap with the -A switch.
m = loaddap ( '-A', url )

m = 

                  Clim_SST: [1x1 struct]
    Clim_StandardDeviation: [1x1 struct]
               Clim_Counts: [1x1 struct]
                 Longitude: [1x1 struct]
                  Latitude: [1x1 struct]
           Clim_SST_Filled: [1x1 struct]
         Global_Attributes: [1x1 struct]

% Hit return to continue...
%
% Now look at the metadata for the Clim_SST dataset.
m.Clim_SST.

ans = 

           solar_corr: '"N/A"'
            limb_corr: '"N/A"'
       nonlinear_corr: '"N/A"'
         sst_equation: '"Pathfinder Version 5.0 NLSST"'
         percent_good: '"N/A"'
         scale_factor: 0.0750
     scale_factor_err: 0
           add_offset: -3
       add_offset_err: 0
        calibrated_nt: 23
            long_name: '"Climatological Mean Sea Surface Temperature"'
                units: '"Degrees C"'
               format: '"F5.2"'
             coordsys: '"geographic"'
        ml__FillValue: 0
          valid_range: [2x1 double]
             C_format: '"%5.2f"'
        missing_value: 0
    DODS_ML_Real_Name: 'Clim_SST'
             Clim_SST: [1x1 struct]
             Latitude: [1x1 struct]
            Longitude: [1x1 struct]

% Hit return to continue...
%
% Now look at the metadata for the Longitude dimension.
m.Clim_SST.Longitude

ans = 

            long_name: '"Longitude"'
                units: '"Degrees East"'
         DODS_ML_Size: 8192
    DODS_ML_Real_Name: 'Longitude'

% Hit return to continue...
%
% Now look at the metadata for the Latitude dimension.
m.Clim_SST.Latitude

ans = 

            long_name: '"Latitude"'
                units: '"Degrees North"'
         DODS_ML_Size: 4096
    DODS_ML_Real_Name: 'Latitude'

% Hit return to continue...


%
% And finally, retrieve the data by making a constraint.
% Because the image is 4096x8192, we'll grab every 10th pixel.
constraint = [url '?Clim_SST[0:10:4095][0:10:8191]'];
constraint

constraint =

http://data.nodc.noaa.gov/cgi-bin/nph-dods/pathfinder/Version5.0_Climatologies/Daily/Day/day001_day.hdf?Clim_SST[0:10:4095][0:10:8191]

% Hit return to continue...
%
% And load the actual data by dropping the '-A' switch to loaddap.
d = loaddap ( constraint );
d.Clim_SST

ans = 

     Clim_SST: [410x820 double]
     Latitude: [410x1 double]
    Longitude: [820x1 double]

pcolor ( d.Clim_SST.Longitude, d.Clim_SST.Latitude, d.Clim_SST.Clim_SST );
shading flat;
colorbar;
drawnow;
% Hit return to continue...
%
% Let's try again and scale the data this time.
% Also, let's take care of missing data (0) and the land mask (1).
% They didn't say the land mask was (1), but it is.
delete(gcf);
sst = d.Clim_SST.Clim_SST;
ind = find((sst==0) | (sst==1));
sst(ind) = NaN;
pcolor ( d.Clim_SST.Longitude, d.Clim_SST.Latitude, sst * 0.075 - 3 ) 
shading flat;
colorbar;