hello all,

i need to put a eigen::VectorXi inside an *int container:


extern "C"{
void R_fastr(int* n, int* p, int* k0,float* x,int* k1,int* RIndexC,int* nsamp,int* J,float* objfunC,int* h_m){
Map<MatrixXf> x_cen(x,*n,*p);
MatrixXf x_cen1 = x_cen;
int h_i=*p+1;
while(Binomial(h_i,*p)<=*k0) h_i++;
int h,j,h_o,i;
float objfunA,objfunB=*objfunC;
VectorXi RIndexB(*h_m);
RIndexB=call_to_a_function_returning_vectorXi(x_cen1)

//here:

for(i=0;i<ih_m;i++){
RIndexC[i]=RIndexB(i);
}

}
}


I was wondering whether there was a way to replace

for(i=0;i<ih_m;i++){
RIndexC[i]=RIndexB(i);
}

by a map/cast/...i.e. a pre-written method.

Best,

I did not read your code, but you can get inspiration from that:

int * data;
VectorXi vec(size);
Map<VectorXi> (data, size) = vec;

Dear ggael,

corrct me if i misunderstood your answer,

it seems your advice would help me move the content of data unto a vectXi object vec (this is covered in the manual).

i'm trying to do the opposite: move the content of a vectorXi to data.


//say:
int n=100;
vector<int> second (n,0);
VectorXi vec= VectorXi::Random(n);


for(int i=0;i<n;i++){
data[i]=vec(i);
}


my question is: is there a method to do this loop?
(a sort of reverse map, really)

what I wrote exactly does that. A Map object is just like an Eigen's matrix object.

thanks, lovely (and how silly oh mr )