Author: luc
Date: Fri Aug 10 18:58:58 2012
New Revision: 1371808
URL: http://svn.apache.org/viewvc?rev=1371808&view=rev
Log:
Added support for x^y in DerivativeStructure and DSCompiler.
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DSCompiler.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructureTest.java
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DSCompiler.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DSCompiler.java?rev=1371808&r1=1371807&r2=1371808&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DSCompiler.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DSCompiler.java
Fri Aug 10 18:58:58 2012
@@ -899,6 +899,26 @@ public class DSCompiler {
}
+ /** Compute power of a derivative structure.
+ * @param x array holding the base
+ * @param xOffset offset of the base in its array
+ * @param y array holding the exponent
+ * @param yOffset offset of the exponent in its array
+ * @param result array where result must be stored (for
+ * power the result array <em>cannot</em> be the input
+ * array)
+ * @param resultOffset offset of the result in its array
+ */
+ public void pow(final double[] x, final int xOffset,
+ final double[] y, final int yOffset,
+ final double[] result, final int resultOffset) {
+ final double[] logX = new double[getSize()];
+ log(x, xOffset, logX, 0);
+ final double[] yLogX = new double[getSize()];
+ multiply(logX, 0, y, yOffset, yLogX, 0);
+ exp(yLogX, 0, result, resultOffset);
+ }
+
/** Compute n<sup>th</sup> root of a derivative structure.
* @param operand array holding the operand
* @param operandOffset offset of the operand in its array
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java?rev=1371808&r1=1371807&r2=1371808&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
Fri Aug 10 18:58:58 2012
@@ -428,6 +428,19 @@ public class DerivativeStructure impleme
return result;
}
+ /** Power operation.
+ * @param e exponent
+ * @return this<sup>e</sup>
+ * @exception DimensionMismatchException if number of free parameters or
orders are inconsistent
+ */
+ public DerivativeStructure pow(final DerivativeStructure e)
+ throws DimensionMismatchException {
+ compiler.checkCompatibility(e.compiler);
+ final DerivativeStructure result = new DerivativeStructure(compiler);
+ compiler.pow(data, 0, e.data, 0, result.data, 0);
+ return result;
+ }
+
/** Exponential.
* @return exponential of the instance
*/
Modified:
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructureTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructureTest.java?rev=1371808&r1=1371807&r2=1371808&view=diff
==============================================================================
---
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructureTest.java
(original)
+++
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructureTest.java
Fri Aug 10 18:58:58 2012
@@ -382,6 +382,28 @@ public class DerivativeStructureTest {
}
@Test
+ public void testPowReciprocalPow() {
+ double[] epsilon = new double[] { 2.0e-15, 2.0e-14, 3.0e-13, 8.0e-12,
3.0e-10 };
+ for (int maxOrder = 0; maxOrder < 5; ++maxOrder) {
+ for (double x = 0.1; x < 1.2; x += 0.01) {
+ DerivativeStructure dsX = new DerivativeStructure(2, maxOrder,
0, x);
+ for (double y = 0.1; y < 1.2; y += 0.01) {
+ DerivativeStructure dsY = new DerivativeStructure(2,
maxOrder, 1, y);
+ DerivativeStructure rebuiltX =
dsX.pow(dsY).pow(dsY.reciprocal());
+ DerivativeStructure zero = rebuiltX.subtract(dsX);
+ for (int n = 0; n <= maxOrder; ++n) {
+ for (int m = 0; m <= maxOrder; ++m) {
+ if (n + m <= maxOrder) {
+ Assert.assertEquals(0.0,
zero.getPartialDerivative(n, m), epsilon[n + m]);
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ @Test
public void testExp() {
double[] epsilon = new double[] { 1.0e-16, 1.0e-16, 1.0e-16, 1.0e-16,
1.0e-16 };
for (int maxOrder = 0; maxOrder < 5; ++maxOrder) {
