 Reza Abdi - 1 year ago 48
C++ Question

Fail in working with a Eigen function

The purpose of the mentioned part of my code is solving a linear equation Ax=b for "A" as a square matrix and "b" as a vector with the same size:

The problem is, I get fail in compiling when I try to use the function of the Eigen in my function:

``````#include "Eigen/Dense"
using namespace Eigen;

void StreamTemperature::avgTemperature() {

TotalDist = pm->get_total_dist();
vector<vector<double>> A(TotalDist, std::vector<double>(TotalDist));
vector<double> b_copy;
VectorXd x_eigen;                               //Eigen format!
MatrixXd A_eigen(TotalDist, TotalDist);
VectorXd b_eigen(TotalDist);

for (int i = 0; i < (TotalDist - 1); i++) {
A[i + 1][i] = 1.0;
A[i][i] = 5.0;
A[i][i + 1] = -1.0;
}
A[TotalDist - 1][TotalDist - 1] = b[TotalDist - 1][j] + c[TotalDist - 1][j];
b_copy.resize(TotalDist);
for (int i = 0; i < TotalDist; i++) { b_copy[i] = 10.0; }

for (int i = 0; i < TotalDist; i++)
A_eigen.row(i) = Map<VectorXd>(A[i].data(), TotalTime);
for (int i = 0; i < TotalDist; i++)
b_eigen(i) = b_copy[i];
x_eigen = A_eigen.colPivHouseholderQr().solve(b_eigen);

for (int i = 0; i < TotalDist; i++) {
x[i] = x_eigen(i);
}

}
``````

The Eigen related part work well in anohter project but I have problem here!
Here is the compiling error:

``````1>e:\suny-files\spring2017\summer2017\runforsyracusemin\itreecoolnewsw\eigen\src/Core/PlainObjectBase.h(659): error C2338: FLOATING_POINT_ARGUMENT_PASSED__INTEGER_WAS_EXPECTED
1>e:\suny-files\spring2017\summer2017\runforsyracusemin\itreecoolnewsw\eigen\src/Core/Matrix.h(250): note: see reference to function template instantiation 'void Eigen::PlainObjectBase<Eigen::Matrix<double,-1,-1,0,-1,-1>>::_init2<T0,T1>(int,int,double *)' being compiled
1>        with
1>        [
1>            T0=double,
1>            T1=double
1>        ]
``````

Any thoughts?! :| AdityaG