#include "genlib.h"
#include "log.h"
#include <math.h>
#include <stdio.h>
#include <time.h>

/*cubic covariance function*/
double cubic(double h) {
    clock_t t = clock();

    log_info("RESULT = in progress, h = %f", h);

    double z;

    if (h >= 1.) {
        z = 0.;
    } else {
        z = 1. - 7. * (double)(h * h) + (35. / 4.) * (double)(h * h * h) - 3.5 * (double)(h * h * h * h * h) + .75 * (double)(h * h * h * h * h * h * h);
    }

    t = clock() - t;
    double time_taken = ((double)t)/CLOCKS_PER_SEC; // calculate the elapsed time

    double* total_ram = malloc(sizeof(double));
    getTotalVirtualMem(total_ram);

    double* used_ram = malloc(sizeof(double));
    getVirtualMemUsed(used_ram);

    log_info("TOTAL VIRTUAL MEM = %5.1f MB, USED VIRTUAL MEM = %5.1f MB, USED VIRTUAL MEM BY CURRENT PROCESS = %d MB", 
    *total_ram, *used_ram, getVirtualMemUsedByCurrentProcess());

    free(total_ram);
    free(used_ram);

    log_info("RESULT = success, z = %f, ELAPSED = %f seconds", z, time_taken);

    return z;
}