The command svmtrain in LIBSVM matlab package takes input for values of C and g in quotes as a string value. I want to use the single code svmtrain repetitively by having different values for C and g. But how to do it?

the command i want to reuse repetitively was:

svmtrain(Label,instance, * * _' -c 12 -g 2 '_**); 
Here how do can i change values of 12 and 2 in a kind of loop continuously?

Answer 1

[Ced]

What you essentially need to do is concatenate strings (and convert the number into a string). Let's say you want to test the vector c = [ 12 16 20 ] and g = [ 2 3 4 ](one at a time).

You can then create your option-string directly as:

for i = 1:length(c)
  opt = [ '-c ' num2str(c(i)) ' -g ' num2str(g(i)) ];
  % now call svmtrain
end

or use sprintf

for i = 1:length(c)
  opt = sprintf('-c %i -g %i',c(i),g(i));
  % now call svmtrain
end

For me, the second option is more readable, especially if you have a lot of options.

Cheers

[prashanth shyamala]

This worked for me which was of mighty help and saved a lot of time. Thanks!! Cheers!