error in using fscanf

I have a script like this:

%Inputing POE

file_01='POE_0.01.txt';

fid=fopen(file_01, 'r');

FileName_01=fscanf(fid,'%g %g %g', [3,Inf])';

Mag_01=FileName_01(:,1); % moment magnitude

Dist_01=FileName_01(:,2); % distance

POE_01=FileName_01(:,3); % probability of exceedance

I = (mod(1:length(Mag_01),30)==1);

Mag = Mag_01(I);

Dist = Dist_01(1:30);

POE_01 = reshape(POE_01,30,15);

marginal(1:15,1) = sum(POE_01);

file_POE = ['POE_0.5.txt','POE_0.2.txt','POE_0.1.txt','POE_0.05.txt', ...

'POE_0.02.txt','POE_0.01.txt','POE_0.005.txt'];

for i = 1:7

file_temp=file_POE(i);

fid=fopen(file_temp, 'r');

FileName_temp=fscanf(fid,'%2.2f %g %g', [3,Inf])';

POE=FileName_temp(:,3); % probability of exceedance

marginal(1:15,i)=sum(reshape(POE,30,15));

temp=sum(marginal);

hold on

plot(Mag,marginal(1:15,i)/temp(i),'DisplayName',file_POE(i))

xlabel('Magnitude (Mw)');

ylabel('Contribution to the Hazard');

end

xlim([4.5 8.8])

legend

I got a massage about :

Error using fscanf

Invalid file identifier. Use fopen to generate a valid file identifier.

Error in inputing_data (line 73)

FileName_temp=fscanf(fid,'%g %g %g', [3,Inf

Is there any one can help?

Answer 1

[Harshavardhan]

Hi @Skydriver

The script is probably failing because the file identifier “fid” is invalid. This happens when “fopen” is unable to find the file with the file name provided.

To solve this issue, ensure that file names are accurate and exist in the current folder or folder on the MATLAB path. If they aren’t in the current folder or folder on the MATLAB path, the full paths of the files must be provided.

For more information you can check out the documentation of “fopen” - https://www.mathworks.com/help/matlab/ref/fopen.html

Moreover, you can refer to this similar question - i had an error in my program with the fscanf i can't understand why it does not work?? thank you in advance - MATLAB Answers - MATLAB Central

Hope this helps.