99 lines
1.7 KiB
C++
99 lines
1.7 KiB
C++
#include <armadillo>
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#include <cmath>
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#include <fstream>
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#include <iomanip>
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#include <ios>
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#include <string>
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arma::vec* general_algorithm(
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arma::vec* sub_diag,
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arma::vec* main_diag,
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arma::vec* sup_diag,
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arma::vec* g_vec
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)
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{
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}
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arma::vec* special_algorithm(
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double sub_sig,
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double main_sig,
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double sup_sig,
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arma::vec* g_vec
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)
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{
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}
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void error(
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std::string filename,
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arma::vec* x_vec,
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arma::vec* v_vec,
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arma::vec* a_vec
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)
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{
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std::ofstream ofile;
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ofile.open(filename);
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if (!ofile.is_open()) {
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exit(1);
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}
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for (int i=0; i < a_vec->n_elem; i++) {
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double sub = (*a_vec)(i) - (*v_vec)(i);
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ofile << std::setprecision(8) << std::scientific << (*x_vec)(i)
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<< std::setprecision(8) << std::scientific << std::log10(std::abs(sub))
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<< std::setprecision(8) << std::scientific << std::log10(std::abs(sub/(*a_vec)(i)))
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<< std::endl;
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}
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ofile.close();
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}
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double analytic_solution(double x) {
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return 100*std::exp(-10*x);
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}
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void build_array(
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int n_steps,
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arma::vec* sub_diag,
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arma::vec* main_diag,
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arma::vec* sup_diag,
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arma::vec* g_vec
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)
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{
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sub_diag->resize(n_steps-2);
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main_diag->resize(n_steps-1);
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sup_diag->resize(n_steps-2);
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sub_diag->fill(-1);
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main_diag->fill(2);
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sup_diag->fill(-1);
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g_vec->resize(n_steps-1);
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double step_size = 1./ (double) n_steps;
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for (int i=0; i < n_steps-1; i++) {
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(*g_vec)(i) = analytic_solution((i+1)*step_size);
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}
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}
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int main()
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{
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arma::vec sub_diag, main_diag, sup_diag, g_vec;
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int n_steps;
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// Timing
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for (int i=1; i <= 6; i++) {
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n_steps = std::pow(10, i);
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// construct arrays
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}
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}
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