Author: luc
Date: Sat Apr 25 16:59:19 2009
New Revision: 768565
URL: http://svn.apache.org/viewvc?rev=768565&view=rev
Log:
fixed an Adams-Moulton order error, it was one unit too large
and inconsistent with the order of the underlying predictor
Modified:
commons/proper/math/trunk/src/java/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegrator.java
commons/proper/math/trunk/src/test/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegratorTest.java
Modified:
commons/proper/math/trunk/src/java/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegrator.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/java/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegrator.java?rev=768565&r1=768564&r2=768565&view=diff
==============================================================================
---
commons/proper/math/trunk/src/java/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegrator.java
(original)
+++
commons/proper/math/trunk/src/java/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegrator.java
Sat Apr 25 16:59:19 2009
@@ -83,7 +83,7 @@
super(METHOD_NAME, order + 1, new AdamsMoultonStepInterpolator());
// compute the integration coefficients
- int[][] bdArray =
AdamsBashforthIntegrator.computeBackwardDifferencesArray(order + 1);
+ int[][] bdArray =
AdamsBashforthIntegrator.computeBackwardDifferencesArray(order);
Fraction[] gamma =
AdamsBashforthIntegrator.computeGammaArray(order);
predictorCoeffs = new double[order];
@@ -97,10 +97,10 @@
}
Fraction[] gammaStar = computeGammaStarArray(order);
- correctorCoeffs = new double[order + 1];
- for (int i = 0; i <= order; ++i) {
+ correctorCoeffs = new double[order];
+ for (int i = 0; i < order; ++i) {
Fraction fCorrector = Fraction.ZERO;
- for (int j = i; j <= order; ++j) {
+ for (int j = i; j < order; ++j) {
Fraction f = new Fraction(bdArray[j][i], 1);
fCorrector = fCorrector.add(gammaStar[j].multiply(f));
}
@@ -272,7 +272,7 @@
* @param order order of the integration method
* @return gamma star coefficients array
*/
- static Fraction[] computeGammaStarArray(final int order) {
+ public static Fraction[] computeGammaStarArray(final int order) {
// create the array
Fraction[] gammaStarArray = new Fraction[order + 1];
Modified:
commons/proper/math/trunk/src/test/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegratorTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegratorTest.java?rev=768565&r1=768564&r2=768565&view=diff
==============================================================================
---
commons/proper/math/trunk/src/test/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegratorTest.java
(original)
+++
commons/proper/math/trunk/src/test/org/apache/commons/math/ode/nonstiff/AdamsMoultonIntegratorTest.java
Sat Apr 25 16:59:19 2009
@@ -46,25 +46,25 @@
public void testCorrectorCoefficients() {
- double[] coeffs1 = new AdamsMoultonIntegrator(1,
0.01).getCorrectorCoeffs();
+ double[] coeffs1 = new AdamsMoultonIntegrator(2,
0.01).getCorrectorCoeffs();
assertEquals(2, coeffs1.length);
assertEquals(1.0 / 2.0, coeffs1[0], 1.0e-16);
assertEquals(1.0 / 2.0, coeffs1[1], 1.0e-16);
- double[] coeffs2 = new AdamsMoultonIntegrator(2,
0.01).getCorrectorCoeffs();
+ double[] coeffs2 = new AdamsMoultonIntegrator(3,
0.01).getCorrectorCoeffs();
assertEquals(3, coeffs2.length);
assertEquals( 5.0 / 12.0, coeffs2[0], 1.0e-16);
assertEquals( 8.0 / 12.0, coeffs2[1], 1.0e-16);
assertEquals(-1.0 / 12.0, coeffs2[2], 1.0e-16);
- double[] coeffs3 = new AdamsMoultonIntegrator(3,
0.01).getCorrectorCoeffs();
+ double[] coeffs3 = new AdamsMoultonIntegrator(4,
0.01).getCorrectorCoeffs();
assertEquals(4, coeffs3.length);
assertEquals( 9.0 / 24.0, coeffs3[0], 1.0e-16);
assertEquals(19.0 / 24.0, coeffs3[1], 1.0e-16);
assertEquals(-5.0 / 24.0, coeffs3[2], 1.0e-16);
assertEquals( 1.0 / 24.0, coeffs3[3], 1.0e-16);
- double[] coeffs4 = new AdamsMoultonIntegrator(4,
0.01).getCorrectorCoeffs();
+ double[] coeffs4 = new AdamsMoultonIntegrator(5,
0.01).getCorrectorCoeffs();
assertEquals(5, coeffs4.length);
assertEquals( 251.0 / 720.0, coeffs4[0], 1.0e-16);
assertEquals( 646.0 / 720.0, coeffs4[1], 1.0e-16);
@@ -72,7 +72,7 @@
assertEquals( 106.0 / 720.0, coeffs4[3], 1.0e-16);
assertEquals( -19.0 / 720.0, coeffs4[4], 1.0e-16);
- double[] coeffs5 = new AdamsMoultonIntegrator(5,
0.01).getCorrectorCoeffs();
+ double[] coeffs5 = new AdamsMoultonIntegrator(6,
0.01).getCorrectorCoeffs();
assertEquals(6, coeffs5.length);
assertEquals( 475.0 / 1440.0, coeffs5[0], 1.0e-16);
assertEquals(1427.0 / 1440.0, coeffs5[1], 1.0e-16);
@@ -81,7 +81,7 @@
assertEquals(-173.0 / 1440.0, coeffs5[4], 1.0e-16);
assertEquals( 27.0 / 1440.0, coeffs5[5], 1.0e-16);
- double[] coeffs6 = new AdamsMoultonIntegrator(6,
0.01).getCorrectorCoeffs();
+ double[] coeffs6 = new AdamsMoultonIntegrator(7,
0.01).getCorrectorCoeffs();
assertEquals(7, coeffs6.length);
assertEquals( 19087.0 / 60480.0, coeffs6[0], 1.0e-16);
assertEquals( 65112.0 / 60480.0, coeffs6[1], 1.0e-16);
@@ -91,7 +91,7 @@
assertEquals( 6312.0 / 60480.0, coeffs6[5], 1.0e-16);
assertEquals( -863.0 / 60480.0, coeffs6[6], 1.0e-16);
- double[] coeffs7 = new AdamsMoultonIntegrator(7,
0.01).getCorrectorCoeffs();
+ double[] coeffs7 = new AdamsMoultonIntegrator(8,
0.01).getCorrectorCoeffs();
assertEquals(8, coeffs7.length);
assertEquals( 36799.0 / 120960.0, coeffs7[0], 1.0e-16);
assertEquals( 139849.0 / 120960.0, coeffs7[1], 1.0e-16);
@@ -102,7 +102,7 @@
assertEquals( -11351.0 / 120960.0, coeffs7[6], 1.0e-16);
assertEquals( 1375.0 / 120960.0, coeffs7[7], 1.0e-16);
- double[] coeffs8 = new AdamsMoultonIntegrator(8,
0.01).getCorrectorCoeffs();
+ double[] coeffs8 = new AdamsMoultonIntegrator(9,
0.01).getCorrectorCoeffs();
assertEquals(9, coeffs8.length);
assertEquals( 1070017.0 / 3628800.0, coeffs8[0], 1.0e-16);
assertEquals( 4467094.0 / 3628800.0, coeffs8[1], 1.0e-16);
@@ -183,9 +183,9 @@
pb.getInitialTime(), pb.getInitialState(),
pb.getFinalTime(), new double[pb.getDimension()]);
- assertTrue(handler.getLastError() < 7.0e-12);
- assertTrue(handler.getMaximalValueError() < 4.0e-11);
- assertEquals(0, handler.getMaximalTimeError(), 1.0e-14);
+ assertTrue(handler.getLastError() < 3.0e-10);
+ assertTrue(handler.getMaximalValueError() < 2.0e-9);
+ assertEquals(0, handler.getMaximalTimeError(), 1.0e-15);
assertEquals("Adams-Moulton", integ.getName());
}
