2nd_Sem_Bogachev/2025.04.04/14Ex/matrix.c
2025-04-02 00:14:36 +03:00

93 lines
1.7 KiB
C

#include "matrix.h"
#include <math.h>
void init_vec_b(const double * restrict a, double * restrict b, int n)
{
#pragma omp parallel for
for (int i = 0; i < n; ++i)
{
double sum = 0;
#pragma omp simd reduction(+:sum)
for (int k = 0; k < n; k+=2)
sum += a[i * n + k];
b[i] = sum;
}
}
void matvec_mul(int n, const double * restrict A, const double * restrict x, double * restrict x_k)
{
#pragma omp parallel for
for (int i = 0; i < n; i++)
{
double sum = 0;
#pragma omp simd reduction(+:sum)
for (int j = 0; j < n; j++)
sum += A[i * n + j] * x[j];
x_k[i] = sum;
}
}
double get_r1(const int n, const double * restrict A, const double * restrict X)
{
double maximum = 0;
if (n > 4000) return 0;
#pragma omp parallel for reduction(max:maximum)
for (int j = 0; j < n; ++j)
{
double sum = 0;
#pragma omp simd reduction(+:sum)
for (int i = 0; i < n; ++i)
{
int in = i*n;
double sum_ij = - (i == j);
#pragma omp simd reduction(+:sum_ij)
for (int k = 0; k < n; ++k)
sum_ij += A[in + k] * X[k*n + j];
sum += fabs(sum_ij);
}
if (maximum < sum)
maximum = sum;
}
return maximum;
}
double get_r2(const int n, const double * restrict A, const double * restrict X)
{
double maximum = 0;
if (n > 4000) return 0;
#pragma omp parallel for reduction(max:maximum)
for (int j = 0; j < n; ++j)
{
double sum = 0;
#pragma omp simd reduction(+:sum)
for (int i = 0; i < n; ++i)
{
int in = i*n;
double sum_ij = - (i == j);
#pragma omp simd reduction(+:sum_ij)
for (int k = 0; k < n; ++k)
sum_ij += X[in + k] * A[k*n + j];
sum += fabs(sum_ij);
}
if (maximum < sum)
maximum = sum;
}
return maximum;
}