Pass data between C++ Eigen Matrix and MATLAB mxArray with a cell array

I would like to pass data between Eigen Matrix/Vector and mex arrays. In the following code, I defined a mex array called y_output, which contains a cell array. The variable y_output will be passed to MATLAB. Each element in y_output is a vector but with different lengths. I would like to pass a pointer that points to Eigen vectors to the mex array y_output.

Notice that the data stored in y will be modified with a user-defined function. After calling the function, I would assume that the data stored in y_output will be modified corresponding. However, I cannot directly pass the pointer from y_output to y. Is there any way to make it possible? Thanks!

#include "mex.h"
#include "matrix.h"
#include <Eigen>


void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{


// prhs[0]: a cell array of length T, each element is a vector with different lengths
mwSize T =  mxGetNumberOfElements(prhs[0]);
mwSize* n = new mwSize[T];
Eigen::VectorXd* z = new Eigen::VectorXd[T];

for(int t=0; t<T; t++){
    n[t] = mxGetNumberOfElements(mxGetCell(prhs[0], t));
    z[t] = Eigen::Map<Eigen::VectorXd>(mxGetPr(mxGetCell(prhs[0], t)), n[t]);
}

// create a cell matrix with T rows and one columns
mxArray* y_output = mxCreateCellMatrix(T,1);
// create corresponding Eigen objects
Eigen::VectorXd* y = new Eigen::VectorXd[T]();
Eigen::VectorXd y_temp(n[0]); y_temp.setZero();

for(int t=0; t<T; t++){
    mxSetCell(y_output, t, mxCreateDoubleMatrix(n[t], 1, mxREAL));
    y[t] = Eigen::VectorXd::Zero(n[t]);
    y_temp.resize(n[t]);
    Eigen::Map<Eigen::VectorXd> y[t](mxGetPr(mxGetCell(y_output, t)), n[t]); // This is not correct!
}
// Myfun(y, z); // y is modified

// set output
plhs[0] = y_output;
}

[Bayes]

I figured a solution at Stack Overflow, see answer.