dynamic name variable as the output of a function

Hello,

I have a function that I call several times, in a loop and I change the parameter, and I would like to change the output name.

For example, what I am doing is

for i=1:N
    ipath=eval(sprintf('Pathname%d',i))
    output_i=call_function(ipath)
end

where I have previously defined ipath as some string, for example Pathname1='\home\dir1\'; Pathname2='\home\dir2\'; Pathname3='\home\dir3\'; ... and so on.

And this works, but I want to also change the name of the output_i. That is, I would like to have output_1, output_2, etc., but I have failed until now.

I have tried several things using eval(), but nothing seems to work. I have also tried things like sprintf('output%d',i)=call_function(ipath)

but that doesn't work either. Does anybody have any ideas?

Thank you very much

[Stephen23]

https://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

Answer 2

[Jason Ross]

If you are trying to process a series of files in a directory, there are a few examples here:

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

Generally, the use of eval() should be avoided: http://www.mathworks.com/matlabcentral/answers/51946-systematic-do-not-use-global-don-t-use-eval

[Clara]

Hello Jason, First of all, thanks for answering. I read the links you put. I don't fully comprehend the dangers of eval(). I don't see the problem with the example in the link. But, if I should avoid eval(), do you have any ideas on what could be an alternative solution to my original question?

Thanks,

Answer 3

[Thorsten]

This should do the job:

eval(['output' int2str(i) ' = call_function(ipath);'])

or

eval(['output' int2str(i) ' = call_function(Pathname' int2str(i) ');'])

A better alternative, because faster and more readable, would be to get rid of the eval by using something like

 output(i) = call_function(pathname(i));

[Clara]

This works perfectly! =) Thank you very much for your help.