Is there an easy way to check if complex?

[Jonas Svanberg]

I'm busy writing a laboration for a signal theory course here
at the university. It will focus on gaussian noise and DFT.
Just now I'm writing a function c=conv(a,b) that will make use 
of the fft and ifft functions included in the maindistribution.

My guess is that Octave distinguishes between real and complex
vectors. Am I right? In that case, is there a fast way to check
if a matrix is complex? I think it is nice in a function like
conv() if it produces real vectors when indata is real.

Regards,
                Jonas Svanberg,
                University of Linköping
                Div. of Electrical Engineering, Information Theory
                SWEDEN