How to use

derivative1

method

in

org.ddogleg.stats.UtilGaussian

case 1:
  for (int i = radius; i >= -radius; i--) {
    gaussian[index++] = (float) UtilGaussian.derivative1(0, sigma, i);

@Test
public void derivative1() {
  // numerical derivative
  double expected = deriv1(1.5, 2, 1.8);
  assertEquals(expected,UtilGaussian.derivative1(1.5, 2, 1.8),1e-4);
}