could not open my nc file, error using ncread and loop

this is my code:

files = dir('/media/wrfout_d02_2015-02*');
for i=1:length(files);
filename   = files(i).name;
data_ori   = double(ncread(filename,'PM10'));

and I got this error;

Error using internal.matlab.imagesci.nc/openToRead (line 1259)
Could not open wrfout_d02_2015-02-01_00:00:00 for reading.
Error in internal.matlab.imagesci.nc (line 121)
                  this.openToRead();
Error in ncread (line 53)
ncObj   = internal.matlab.imagesci.nc(ncFile);

can anyone help me? what is the error mean? thank you

Answer 1

[Walter Roberson]

projectdir = '/media';
files = dir( fullfile(projectdir, 'wrfout_d02_2015-02*') );
for i = 1:length(files);
  filename = fullfile(projectdir, files(i).name );
  data_ori   = double(ncread(filename,'PM10'));
end

[nsyn]

oh thanks, it works now

[nsyn]

oh sorry, Mr. Walter Roberson, there is no error when I am running the code above, but when I check "files" it shows

>> files
files =
0x1 struct array with fields:
  name
  date
  bytes
  isdir
  datenum

it means the loop command doesn't work, does it? please give any advice, I have checked my directory is right.

[Walter Roberson]

Did you truly put the files directly in /media ? That would be rather unusual: /media is almost always used to mount filesystems so there would be a mount-point directory name under /media and files would be underneath that.

[nsyn]

No, I didn't put it directly in media, I just wrote it there to make it simple. in my real code following your instruction above, I write like this:

projectdir = '/media/Seagate1/myaccount/2015output/';
files      = dir(fullfile(projectdir,'wrfout_d02_2015_02*'));
for i=1:length(files)
filename   = fullfile(projectdir, files(i).name);
data_ori   = double(ncread(filename,'PM10'));
end

I have checked the location of the files and it's correct. just for information, when I run my first code like shown in my first question, shown:

>> files
files =
672x1 struct array with fields:

in my opinion, the loops command was correct but the error in "ncread filename", what do you think? please help me to solve it.

[Walter Roberson]

If you are using R2016b or later (or is it R2017a or later?) you can use

files = dir('/media/Seagate1/myaccount/2015output/wrfout_d02_2015-02*');
for i=1:length(files);
  filename   = fullfile(files(i).folder, files(i).name);
  data_ori   = double(ncread(filename,'PM10'));
end