69 lines
1.5 KiB
C
69 lines
1.5 KiB
C
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/*
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* Sequential version.
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* No paralleliization used.
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*/
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#include <stdio.h>
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#include <math.h>
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#include "../config/config.h"
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typedef struct borders {
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double north;
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double east;
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double south;
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double west;
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} borders;
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void compute_jacobi(int n, double init_value, double threshold, borders b);
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int main(int argc, char* argv[]) {
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int config_loaded;
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configuration config;
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borders b;
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config_loaded = load_config(&config);
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if (config_loaded != 0) {
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return 1;
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}
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b.north = config.north;
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b.east = config.east;
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b.south = config.south;
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b.west = config.west;
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compute_jacobi(config.n, config.init_value, config.threshold, b);
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return 0;
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}
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void compute_jacobi(int n, double init_value, double threshold, borders b) {
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double x[n + 2][n + 2];
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double max_diff, new_x;
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int i, j;
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/* Initialize boundary regions */
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for (i = 1; i <= n; i++) {
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x[0][i] = b.north;
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x[n + 1][i] = b.south;
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x[i][0] = b.west;
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x[i][n + 1] = b.east;
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}
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/* Initialize the rest of the matrix */
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for (i = 1; i <= n; i++) {
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for (j = 1; j <= n; j++) {
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x[i][j] = init_value;
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}
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}
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/* Iterative refinement of x until values converge */
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do {
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max_diff = 0;
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for (i = 1; i <= n; i++) {
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for (j = 1; j <= n; j++) {
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new_x = 0.25 * (x[i - 1][j] + x[i][j + 1] + x[i + 1][j] + x[i][j - 1]);
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max_diff = (double) fmax(max_diff, fabs(new_x - x[i][j]));
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x[i][j] = new_x;
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}
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}
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} while (max_diff > threshold);
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}
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