unable to convert 'rsgenpoly' even though support is provided for c/c++ conversion

The function 'rsgenpoly' has the support for extended c/c++ library generation, but when converting it provides the error that

Code generation cannot handle Galois field output. Please set the parameter 'outputFormat' of rsgenpoly function to 'double'.

function [ g ] = gen_poly(n,k) %#codegen
g=rsgenpoly(n,k);
end

But MATLAB doesn't allow changes in the inbuilt function.

Please suggest!

[Walter Roberson]

rsgenpoly(n, k, 'outputformat', 'double')

Possibly?

[Puneet Khurana]

Thank you, I will try it. Also I have a query too. Will the code generated by the coder work for rsgenpoly and deconv when the input is not gf class but an array?

[Walter Roberson]

I guessed at the syntax; the help file gives the example

g4 = rsgenpoly(7,3,[],[],'double') % Output the generator polynomial as a GF array

For code generation, all inputs must be constant. MATLAB will generate the values at the time of compile, so the code that is embedded will simply be a vector of doubles, which is what deconv expects.

[Puneet Khurana]

yes the above mentioned code works and produce the gen poly. But when used, produces different ans.

i.e.

[q,r]=deconv(msg,g4);

where both msg and g4 are vector of doubles produces different 'q' and 'r' as opposed to when both 'msg' and 'g4' are gf arrays.

This makes it difficult to perform rsenc, rsgenpoly, deconv etc. in code generation and thus using in c/c++

Answer 1

[Mike McLernon]

If you would like to generate C/C++ code with RS encode/decode functionality, you can try the RS System objects. The comm.RSEncoder ref page is here, and the comm.RSDecoder ref page is here.