Techniques in using liboctave and liboctinterp from C++ program

[John Swensen]

I have started using the datatypes and operations of Octave from C++  
for my research and have a few questions.

1) Can builtin functions and DLD-FUNCTIONS (e.g. find, eig, conv2,  
etc) be used directly from C++?

2) In the documentation, is there a list of overloaded operators for  
octave_value objects of different types?  For example, I was trying to  
do the following:
Matrix A(768,1024);
Matrix B(1,1);
Matric C = A*B;
This, however, didn't work.  Instead, I had to declare B as a scalar  
double as follows:
Matrix A(768,1024);
double b;
Matrix C = A*B;
This isn't necessarily a problem, but it would be nice if there was a  
list of possible overloads somewhere.

3) I often do image thresholding after I have processed it a bit.  In  
the Octave interpreter I can simply type 'im2 = im1>0.5'.  I tried  
doing the following, but it didn't work:
Matrix A(768,1024);
double B = 0.5;
Matrix C = A>B;
If I could find out where that bit of the interpreter was implemented,  
I could figure it out, but I searched through the sources a bit and  
couldn't find anything.

John Swensen