i am trying to save .mat file but its not working.

eval(['save D:\F' int2str(I_fno) '\A' int2str(I_D) '_' int2str(I_NP) '_' int2str(s) ' Best_mat;'])

error:

??? Error using ==> save
Unable to write file D:\F2\A240_50_1: No such file or directory.

Error in ==> Run at 53
eval(['save D:\F' int2str(I_fno) '\A' int2str(I_D) '_' int2str(I_NP) '_'
int2str(s) ' Best_mat;'])

[Stephen23]

Don't use eval for such trivial code.

eval makes your life much more difficult by hiding all of the useful code hinting, warnings and error messages that you would get is you wrote code properly, without eval.

Although beginners all seem to believe that eval solves every code challenge, it actually just creates many more problems than it solves, which is exactly what you are experiencing now.

Summary: don't use eval.

Read this to know more about why it a poor programming practice:

http://www.mathworks.com/matlabcentral/answers/196952-how-to-create-new-variables-in-batches-with-strcat

Answer 1

[Thorsten]

You evaluate the string

 save D:\F2\A240_50_1 Best_mat;

That is, you try to save the variable 'Best_mat' to the file A240_50_1 in directory D:\F2\

The error tells you that the directory D:\F2\ does not exist.

So you have to create it with

mkdir('D:\F2')

Don't use eval, but

filename = ['D:\F' int2str(I_fno) '\A' int2str(I_D) '_' int2str(I_NP) '_' int2str(s)];
save(filename, 'Best_mat')

[Image Analyst]

He did not use fullfile() unfortunately. Best does not have a \ in front of it, so Best_mat is now part of the folder. So there is no base filename or extension, like Best.mat or whatever. The complete string is only a folder name, for example filename = 'D:\F9\A2_3_4 Best_mat' instead of filename ='D:\F9\A2_3_4\Best.mat'.

[Muhammad Umer]

i tried this code

filename=['D:\F' int2str(I_fno) '\A' int2str(I_D) '_' int2str(I_NP) '_' int2str(s)];
save(filename,' Best_mat');

but i am getting an error

??? Index exceeds matrix dimensions.

Error in ==> Run at 55
save(filename,' Best_mat');

[Thorsten]

Have you overwritten save?

which save

Also get rid of the blank before Best. Variables in Matlab cannot start with blank. Should read

 save(filename, 'Best_mat');

[Muhammad Umer]

Code:

filename=['D:\F' int2str(I_fno) '\A' int2str(I_D) '_' int2str(I_NP) '_' int2str(s)];
save(filename, 'Best_mat');

Error:

??? Error using ==> save
Unable to write file D:\F2\A240_50_1: No such file or directory.

Error in ==> Run at 55
save(filename,'Best_mat');

[Thorsten]

What does the following command return?

isdir('D:\F2')

[Walter Roberson]

pathname = sprintf('D:\\F%d', I_fno);
filename = fullfile( pathname, sprintf('A%d_%d_%d.mat', I_D, IN_P, s) );
if ~exist(pathname, 'dir')
  mkdir(pathname);
end
save(filename, 'Best_mat')

[Muhammad Umer]

this one is working

filename=['D:\F2\A' int2str(I_D) '_' int2str(I_NP) '_' int2str(s)];
save(filename, 'Best_mat');

[Walter Roberson]

I corrected my version with sprintf().