Extract data from NetCDF files to text files (For SWAT Model).

% new code to extract data from netcdf file to SWAT format text file.
data =[];
Files = dir('*.nc');
for k=1:length(Files)
    FilesNames = Files(k).name;
    for t=1:2
        pr = ncread(FilesNames,'rainfall_amount');
        long =  ncread(FilesNames,'x');
        lat = ncread(FilesNames,'y');
    end
    for j = 716:746(lat);
        for i = 328:368(long);
            
            v = pr(i,j,:);
            data2 = (v);
            data2(isnan(data2)) = -99.0;
            
            outfile =sprintf('%d_%d_PCP.txt',lat(j),long(i));
            fopen all
            fid = fopen(outfile,'wt');
            data = {data;data2};
            fprintf(fid,'%5.1f\n',data2);
        end
        fclose all
    end
end
disp([outfile 'created'])
% original code source: 
% http://dficklin.weebly.com/netcdf-to-swat-climate-input-files.html

[Image Analyst]

What's the problem? Please read this link

Was en error thrown? Did you have an error with ncread()? Or fprintf()? Or these lines

    for     j = 716:746(lat);
    for     i = 328:368(long);
        

Get rid of the (lat) and (long) and the semicolons.

Or is it something else?

[shobhit pipil]

Hi,

these lat long creates a spatial subset.

at the end of processing I am just getting one year data. though I am extracting data from two netcdf files and data2 varaiable should hold the two years data (730 days). instead of that extrcted txt files have 365 records for the processed netcdf file. programme still reading both files.

No, I didnt get any error message for mentioned code. Eralier, I was getting negative fid values and preallocation problem that I have fixed it.

thanks

shobhit

[Image Analyst]

Please read the link I gave you. I know you haven't yet read it because you have not attached the two data files. So please read it.

[shobhit pipil]

outfiles shows 365 days records instead of 730 days, because single netcsd contains 1 year records per lat long.

NetCDF data download link: https://my.pcloud.com/publink/show?code=XZ60yC7ZmQaTSzygQ6FO1Gvlex2yTXYH3piX

one can copy the same NetCDF file in same directory and change year from 1890 to 91 for testing the code for two files. Single file size is 4.5 GB so I have uploaded just one.

Thanks

Answer 1

[shobhit pipil]

Now It works for me:-

% new code to extract data from netcdf file to SWAT format text file.
data =[];
Files = dir('*.nc');
for k=1:length(Files)
    FilesNames = Files(k).name;
    for t=1:2
        pr = ncread(FilesNames,'rainfall_amount');
        long =  ncread(FilesNames,'x');
        lat = ncread(FilesNames,'y');
    end
        
    for j = 716:746(lat);
        for i = 328:368(long);
            outfile =sprintf('%d_%d_PCP.txt',lat(j),long(i));
            fopen all;
            
            v = pr(i,j,:);
            data2 = (v);
            data2(isnan(data2)) = -99.0;
            
     %       outfile =sprintf('%d_%d_PCP.txt',lat(j),long(i));
     %       fopen all;
            fid = fopen(outfile,'At');
            data = {data;data2};
            fprintf(fid,'%5.1f\n',data2);
        end
        fclose all;
    end
end
disp([outfile 'created'])
% original code source: 
% http://dficklin.weebly.com/netcdf-to-swat-climate-input-files.html