flag an error message when a scalar is complex

Hi,

I would like to include in my algorithm an error message where it will tell me that a scalar is complex. So for example I would like to implement in Matlab the following idea

if scalar == complex number 
   show error message 
end

How I can implement this Matlab ?

Thanks

Answer 1

[Nobel Mondal]

if ~isreal(num)
   error('This is a complex number.')
end

[msh]

Thanks for the quick response. One clarification. In the ~isreal(num) , num is the relevant scalar, correct? can this be also extended to matrices ?

[Nobel Mondal]

Yes, num is the scalar which you want to check for.

For matrix:

>> A = [ 1 2 3; 4 5+6i 7];

>> isreal(A)
   ans = 
        0

>> isreal(A(1,1))
   ans = 
        1

>> isreal(A(2,2))
   ans = 
        0

Hope this clear things up for you.