what is the function of 'eval' ?

Hi Please explain what function is eval performing here and is it necessary to use it. I'm planning to use eval function to store code book, is there any alternative.

clc; Nsamp=35000; fs=8050; beep I=wavrecord(Nsamp,fs);

codebook = MFCC_BasedCodebook(I,fs); in=inputdlg('Enter file name -5 characters'); FileName=cell2mat(in); eval(['save ' 'test\' FileName ' codebook;']);

Thank you

[Stephen23]

"... is it necessary to use it."

It is not necessary to use it, its usage here marks this code as being extremely badly written.

"I'm planning to use eval function to store code book, is there any alternative."

https://www.mathworks.com/help/matlab/matlab_prog/command-vs-function-syntax.html

save(fullfile('test',in{1}),'codebook')

Additionally: https://www.mathworks.com/help/matlab/ref/uiputfile.html

Answer 1

[lvn]

Eval can be used to run matlab commands which are not known in advance, but only at runtime. In your example eval executes the commando 'save test\FileName codebook' (with filename the specific filename constructed above).

The use of eval is not recommended http://www.mathworks.nl/help/matlab/matlab_prog/string-evaluation.html and in your case, it can simply be replaced by using the different syntax of the save commando ('help save') e.g.

save(sprintf('test\\%s',FileName),'codebook');