MATLAB: Output type definition for extrinsic function (polyxpoly) in Simulink

coder.extrinsicfunction blockmatlab codermxarraypolyxpolysimulink

Hi,
I'm needing to use an extrinsic function in an embedded matlab block in simulink (polyxpoly).
My problem is that the output of this function is an x by 2 array where x varies. I am therefore unable to define the output type without getting an mxarray error.
How can I make use of this function in a simulink matlab function block?

Best Answer

Since the Embedded MATLAB block uses static memory allocation, it cannot handle variables that change size dynamically. What you can do is declare your output as variable-sized while specifying an upper bound for the size.
   function y = myfun(x)
   coder.varsize('y', [1024 2]); %x must never exceed 1024
   coder.extrinsic('polyxpoly');
   y = zeros(x, 2); %pre-declare the type and size of y
   y = polyxpoly(x, other_args, ...);
Also, be sure to configure the output as variable-size on the Ports and Data Manager.
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