simulacion-permeabilidad/fftma_module/gen/sources/cubic.c

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


/*cubic covariance function*/
double cubic(double 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);
  }
  return (z);
}