@Override
public void setParameterValues(double... params) {
int nparams = Math.min(params.length, getNoOfParameters());
for (int n = 0; n < nparams; n++) {
parameterList.get(n).setValue(params[n]);
}
for (AFunction f : functionList) f.dirty = true;
dirty = true;
}
/**
* 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;
}
/**
* Create a set of datasets each containing the composite function and its constituent parts
* evaluated over the values
*
* @param XValues A dataset containing all the X values to calculate the data at
* @param DataValues The data that is being fitted too, for visual help.
* @return an array of datasets
*/
public DoubleDataset[] display(DoubleDataset XValues, DoubleDataset DataValues) {
int noOfFunctions = getNoOfFunctions();
DoubleDataset[] outputs = new DoubleDataset[noOfFunctions + 4];
outputs[0] = new DoubleDataset(DataValues);
outputs[1] = makeDataset(XValues);
outputs[1].setName("Composite function");
// now add the data
for (int i = 0; i < XValues.getSize(); i++) {
double value = val(XValues.get(i));
outputs[1].set(value, i);
}
// now add the errors to the graph, this should provide a good view to
// how good the fit is quite nicely.
outputs[2] = new DoubleDataset(XValues);
outputs[2].setName("Error Value");
double offset =
DataValues.min().doubleValue()
- ((DataValues.max().doubleValue() - DataValues.min().doubleValue()) / 5.0);
for (int i = 0; i < XValues.getSize(); i++) {
double value = (val(XValues.get(i)) - DataValues.get(i)) + offset;
outputs[2].set(value, i);
}
outputs[3] = new DoubleDataset(XValues);
outputs[3].setName("Error Offset");
// centre for the error
for (int i = 0; i < XValues.getSize(); i++) {
double value = offset;
outputs[3].set(value, i);
}
// now add the data for each bit in turn
int j = 4;
for (AFunction f : functionList) {
outputs[j] = f.makeDataset(XValues);
outputs[j++].setName(f.getName());
}
return outputs;
}
/**
* Create a set of datasets each containing the composite function and its constituent parts
* evaluated over the values
*
* @param values datasets containing all the values to evaluate the function at
* @return an array of datasets
*/
public DoubleDataset[] display(DoubleDataset... values) {
if (values == null || values.length == 0) {}
int noOfFunctions = getNoOfFunctions();
DoubleDataset[] outputs = new DoubleDataset[noOfFunctions + 1];
outputs[0] = makeDataset(values);
outputs[0].setName("Composite function");
// now add the data for each bit in turn
int j = 1;
for (AFunction f : functionList) {
outputs[j] = f.makeDataset(values);
outputs[j++].setName(f.getName());
}
return outputs;
}
/* function node */
public void outAFunction(AFunction node) {
setValue(
node,
getValue(node.getType())
+ node.getIdentifier().toString()
+ node.getLPar().toString()
+ getValue(node.getArguments())
+ node.getRPar().toString()
+ getValue(node.getCompoundstm()));
}
@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);
}
