if/elseif script problem

Hi there,

I am writing a function designed to take an input note, and return the relevant frequency. However, I keep hitting problems whenever I change the strings slightly.

Here is part of my example that works:

function [f]=note_to_freq(notename)

if notename == 'A'
        f=110;
elseif notename == 'A#'
        f=116;

....etc

end

Now, when I do something like change the elseif notename == 'A#2', Matlab seems to treat notename as a string and compare the two. This then returns the error message:

??? Error using ==> eq
Matrix dimensions must agree.

Any explanations for why this is happening/how to fix it?

Thanks in advance.

Craig

Answer 1

[Daniel Shub]

I would suggest you look into

doc switch

This might be better than lots of if/elseif/elseif...

You should also look at

doc strcmp

As for what is happening, == (which is really the eq function) doesn't like things that are different sizes). Basically, you are trying to do

[65, 35] == [65, 35, 50]

which is obviously confusing. A better fit would be isequal (which will avoid the error), but strcmp is best.

[C Meek]

Thanks! Got it working.