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

/*cardsin covariance function*/
double cardsin(double h)
{
  float delta = 20.371;
  double z;

  if (h != 0) {
    z = (double)(h*delta);
    z = sin(z)/z;
  } else {
    z = 1.;
  }
  return(z);
}