Octave-symbolic package

[Benjamin Brown]

Hello,

I come from a Matlab background, but I've been trying to migrate to octave.  The most important thing that I've been missing is the symbolic toolbox.  Then I found octave-symbolic.  The only issue I'm having is that the usage seems to be a bit different from the Matlab toolbox.  I've defined a number of symbols, z, z_p, b, and a using:

z=sym("z")
z_p=sym("z_p")...


without error.  Then when I try to create an _expression_:

 k=e^(i*b(sqrt((z-z_p)^2+a^2)))/(4*pi*sqrt((z-z_p)^2+a^2))

I get the following errors:

error: mapper: wrong type argument `ex'
error: evaluating argument list element number 1
error: evaluating binary operator `*' near line 11, column 7
error: evaluating binary operator `^' near line 11, column 4
error: evaluating binary operator `/' near line 11, column 31
error: evaluating assignment _expression_ near line 11, column 2


Is there any way you could send me some basic usage sample code for this package.  Any help would be appreciated.

-Benjamin Brown