I have converted some matlab code to C++ using the MATLAB coder.
I am aware that there are some questions similar to this one, but none of the explanations I found did help with my problem, which is somewhat different.
The generated code for C++ gives me the following function:
void getTargetPoint(const emxArray_real_T *eyeMatrix, const emxArray_real_T
*HypAlpha, const emxArray_real_T *HypCov, const
emxArray_real_T *HypMean, const double xs[4], double Ymu[3])
Where Ymu is the output I am looking for. However, even if I defined my inputs as arrays of undetermined size in the converter, they are vectors of vectors in my code:
eyeMatrix = vector<vector <double>>
They all have different dimensions, for instance, eyeMatrix = [968x4], but in any other case it could be [anything x 4]
I have tried many things, but I cannot manage to convert my input data (vector of vectors) into type: emxArray_real_T
Is there anyway to do this? Or should I convert my input data into something else and then into emxArray_real_T?
Any help or idea is greatly appreciated!
This answer assumes that eyeMatrix is a rectangular matrix (i.e. each inner vector has the same length) since the generated code likely is meant to work with non-ragged arrays.
You can check out:
https://stackoverflow.com/a/24271438/3297440
and the documentation for an overview of working with emxArray* data types.
To summarize the answer, you'll have functions declared in the file <name>_emxAPI.h that look like:
extern emxArray_real_T *emxCreateWrapper_real_T(double *data, int rows,
int cols);
extern emxArray_real_T *emxCreate_real_T(int rows, int cols);
You'll notice that the first takes a double *. This should be a pointer to your data stored in column-major order.
Since eyeMatrix is likely in row-major order and may not actually be contiguous (I'm not aware of a guarantee that nested std::vectors result in contiguous data) a first step can be to call emxCreate_real_T with the proper dimensions.
This allocates and returns an emxArray_real_T which we can call emx. emx->size will have 2 elements which are the dimensions you set. The field emx->data will be a pointer to rows*cols values (double values in your case). Then you can just copy the data from eyeMatrix to emx->data in a column-major fashion. So if your matrix is:
1, 2
3, 4
The data in emx->data should be:
1, 3, 2, 4
From there, just pass emx as the input.
Lastly, don't forget to call the proper emxDestroyArray* functions to clean up any allocated memory when you are done with the emxArray_real_T values.