/**
* Function that evaluates the whole function at a single point
*
* @param position The value to evaluate the function at
* @return A double containing the evaluated value.
*/
@Override
public double val(double... position) {
// Check x and a size for correctness
double y = 0.;
// Just sum over the individual functions
for (AFunction f : functionList) y += f.val(position);
return y;
}
@Test
public void testFunction() {
AFunction f = new StraightLine();
Assert.assertEquals(2, f.getNoOfParameters());
f.setParameterValues(23., -10.);
Assert.assertArrayEquals(new double[] {23., -10.}, f.getParameterValues(), ABS_TOL);
Assert.assertEquals(23. - 10., f.val(1), ABS_TOL);
DoubleDataset xd = new DoubleDataset(new double[] {-1, 0, 2});
DoubleDataset dx;
dx = f.calculateValues(xd);
Assert.assertArrayEquals(new double[] {-23. - 10, -10, 23. * 2 - 10.}, dx.getData(), ABS_TOL);
dx = f.calculatePartialDerivativeValues(f.getParameter(0), xd);
Assert.assertArrayEquals(new double[] {-1, 0, 2}, dx.getData(), ABS_TOL);
dx = f.calculatePartialDerivativeValues(f.getParameter(1), xd);
Assert.assertArrayEquals(new double[] {1, 1, 1}, dx.getData(), ABS_TOL);
Assert.assertEquals(-1, f.partialDeriv(f.getParameter(0), -1), ABS_TOL);
Assert.assertEquals(1, f.partialDeriv(f.getParameter(1), -1), ABS_TOL);
}
