task_sem3_1.16

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "spline.h"

#define C_M 44.094
#define C_R 0.083144
#define C_T 370

int n; // number of nodes
double *dataP, *dataD; // data arrays
double *c; // service array for spline()

void readData() {
    FILE *f = fopen("data.dat", "r");

    if (!f) {
        printf("Ошибка чтения файла данных data.dat!\n");
        exit(1);
    }

    fscanf(f, "%d", &n);

    dataP = (double *)malloc(sizeof(double) * n);
    dataD = (double *)malloc(sizeof(double) * n);
    c = (double *)malloc(sizeof(double) * n * 3);

    for (int i = 0; i < n; i++) {
        fscanf(f, "%lf", (dataP + i));
        fscanf(f, "%lf", (dataD + i));
    }

    fclose(f);
}

double f(double p, double d) {
    return p * C_M / (d * C_R * C_T);
}

int main(int argc, char *argv[]) {
    double *z;
    FILE *fout;

    readData();

    // way #1
    spline(n, dataP, dataD, c);
    fout = fopen("way1.dat", "w");

    for (double p = 0.1; p <= 0.9; p += 0.1)
        fprintf(fout, "%.10lf\t%.10lf\n", p, f(p, seval(n, p, dataP, dataD, c)));

    for (double p = 1.0; p < 10.0; p += 1.0)
        fprintf(fout, "%.10lf\t%.10lf\n", p, f(p, seval(n, p, dataP, dataD, c)));

    for (double p = 10.0; p < 100.0; p += 10.0)
        fprintf(fout, "%.10lf\t%.10lf\n", p, f(p, seval(n, p, dataP, dataD, c)));

    for (double p = 100.0; p <= 600.0; p += 50.0)
        fprintf(fout, "%.10lf\t%.10lf\n", p, f(p, seval(n, p, dataP, dataD, c)));

    fclose(fout);

    // way #2
    z = (double *)malloc(sizeof(double) * n);

    for (int i = 0; i < n; i++)
        *(z + i) = f(*(dataP + i), *(dataD + i));

    spline(n, dataP, z, c);
    fout = fopen("way2.dat", "w");

    for (double p = 0.1; p <= 0.9; p += 0.1)
        fprintf(fout, "%.10lf\t%.10lf\n", p, seval(n, p, dataP, z, c));

    for (double p = 1.0; p < 10.0; p += 1.0)
        fprintf(fout, "%.10lf\t%.10lf\n", p, seval(n, p, dataP, z, c));

    for (double p = 10.0; p < 100.0; p += 10.0)
        fprintf(fout, "%.10lf\t%.10lf\n", p, seval(n, p, dataP, z, c));

    for (double p = 100.0; p <= 600.0; p += 50.0)
        fprintf(fout, "%.10lf\t%.10lf\n", p, seval(n, p, dataP, z, c));

    fclose(fout);

    free(dataP);
    free(dataD);
    free(c);
    free(z);

    return 0;
}