Why do I get this error?

This is my function:

function download(d)

[date_string]  = datestr(d, 'yyyy-mm-dd')
yyyy = date_string(1:4);
mm = date_string(6:7);
dd = date_string(9:10);

download_string = ['password and username and the link' yyyy mm dd '.nc4'];

disp('Executing this string: ');
disp(download_string);
ncdisp(['MERRA2_400.inst6_3d_ana_Np.' yyyy mm dd '.nc4 '])
system(download_string);

I get this error, why??

Error using internal.matlab.imagesci.nc/openToRead (line 1259)
Could not open MERRA2_400.inst6_3d_ana_Np.20161001.nc4  for reading.

Error in internal.matlab.imagesci.nc (line 121)
                    this.openToRead();

Error in ncdisp (line 50)
ncObj   = internal.matlab.imagesci.nc(ncFile);

Someone know what to do?

[Jan]

The posted code does not run: A [ is missing. Please post the code, which is failing, not some similar code.

[kk1991]

Thanks and sorry. My mistake! However, this is my code. I just have hidden my password and username.

Answer 1

[Jan]

The error message seems to be clear:

 Could not open MERRA2_400.inst6_3d_ana_Np.20161001.nc4  for reading.

There is an empty space at the end of the name, perhaps this matters. Unfortunately this space seems to be inserted exactly in this line, which has an inproper syntax:

ncdisp('MERRA2_400.inst6_3d_ana_Np.' yyyy mm dd '.nc4 '])

Therefore I cannot guess, if the original code contains the same problem.

We cannot know, if this object is existing, but you can and should check this. Please provide the detail, if this file is missing (if it is a file at all, I do not know the command ncdisp.

[kk1991]

If I remove the ncdisp, the file is downloading perfectly. And if I use the ncdisp or ncread in a separate script matlab read the file perfectly. The problem occurs when i put this two scripts together. I tried without the space at the end, but it didn't work, I got the same error.

[Jan]

Perhaps the file is not in the current folder?

file = fullfile(cd, ['MERRA2_400.inst6_3d_ana_Np.' yyyy mm dd '.nc4']);
if ~exist(file, 'file')
  error('File not found: %s', file);
end
ncdisp(file);

Is the file really existing? It will be much better not to use cd, but the real folder name.

[kk1991]

It worked!! Thank you so much for your help! :)