ex3

ex3/code/task_7.cpp

@@ -0,0 +1,43 @@
+#include "task_7.h"
+
+#include <iostream>
+#include <vector>
+#include <cmath>
+#include <lapacke.h>
+using namespace std;
+
+tuple<vector<double>, vector<double>> init_M(size_t N, size_t Nrhs) {
+    vector<double> A(N*N), b(N*Nrhs);
+    for (size_t i = 0; i < N; ++i) {
+        for (size_t j = 0; j < N; ++j) {
+            if (i != j) {
+                A[i*N + j] = 1.0 / pow(abs(1.0*i-1.0*j),2);
+            } else {
+                A[i*N + j] = 4;
+            }
+        }
+        for (size_t j=0; j < Nrhs; ++j) {
+            b[i*Nrhs + j] = 1.0*j;
+        }
+    }
+    return make_tuple(A, b);
+}
+
+void print_matrix(vector<double> &A, size_t M, size_t N) {
+    printf("\n");
+    for (size_t i = 0; i < M; ++i){
+        for (size_t j = 0; j < N; ++j) {
+            printf("%f ", A[i*N + j]);
+        }
+        printf("\n");
+    }
+    printf("\n\n");
+}
+
+void benchmark_lapacke(int N, int Nrhs) {
+    auto [A,b] = init_M(N,Nrhs);
+    int lda=N, ldb=Nrhs;
+    vector<int> ipiv(N);
+    LAPACKE_dgetrf(LAPACK_ROW_MAJOR, N, N, A.data(), lda, ipiv.data());
+    LAPACKE_dgetrs(LAPACK_ROW_MAJOR, 'N', N, Nrhs, A.data(), lda, ipiv.data(), b.data(), ldb);
+}