I am attempting to use LinearSolver in C++ to do some simple matrix and vector solution, as in 3x3 or 5x5. I get this error. [0]PETSC ERROR: --------------------- Error Message ------------------------------------ [0]PETSC ERROR: Object is in wrong state! [0]PETSC ERROR: Not for unassembled matrix! [0]PETSC ERROR: ------------------------------------------------------------------------ [0]PETSC ERROR: Petsc Release Version 3.0.0, Patch 8, Fri Aug 21 14:02:12 CDT 2009 This seems to suggest that I cannot use LinearSolver in the code directly, that instead I have to make a form file. Is this in fact the case? and if so how would I make that form file? This is my code in case it is relevant. I am doing some simple interpolation to calculate a step size for an iterative non-linear problem. This is the test program I wrote. int main() { //declare and initialise int degree = 4; double *x = new double[degree + 1]; double *y = new double[degree + 1]; std::vector columns; std::vector values; dolfin::LinearSolver linSolver; dolfin::Matrix X(degree + 1, degree + 1); dolfin::Vector Y(degree + 1); dolfin::Vector A(degree + 1); //generate test points x[0] = 0; y[0] = 0; x[1] = 1; y[1] = -2; x[2] = 2; y[2] = -1; x[3] = 3; y[3] = -2; x[4] = 4; y[4] = 0; //set vector Y.set_local(y); //set matrix for (int j = 0; j <= degree; j ++) columns.push_back(dolfin::uint(j)); for (dolfin::uint row = 0; row < dolfin::uint(degree); row++){ for (int j = 0; j <= degree; j++) values.push_back( power(x[row], (degree - j) ) ); X.setrow(row, columns, values); values.clear(); } //solve [X]{A} = {Y} where A is the coefficients of the polynomial linSolver.solve(X, A, Y); //output for (int j = 0; j <= degree; j++) std::cout << A[j] << std::endl; //clean up delete [] x; delete [] y; } Any help is appreciated. Thank you.

When	Who	Action	New State
2010-05-28	Garth Wells	Answer	Answered
2010-05-28	Phil Marinier	Confirm	Solved
2010-05-28	Phil Marinier	Comment	Solved
2011-05-31	Nguyen Van Dang	Comment	Solved
2011-05-31	Johan Hake	Comment	Solved
2011-05-31	Nguyen Van Dang	Comment	Solved
2011-05-31	Johan Hake	Comment	Solved
2011-05-31	Nguyen Van Dang	Comment	Solved

DOLFIN

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