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Coding style changes to match the rest of [math]. 

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/math/trunk@359120 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Phil Steitz 2005-12-26 22:53:57 +00:00
parent 25fcfe78f1
commit 159d0b4a90
1 changed files with 29 additions and 23 deletions
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52
src/java/org/apache/commons/math/analysis/LaguerreSolver.java
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@ -17,7 +17,8 @@ package org.apache.commons.math.analysis;
import org.apache.commons.math.ConvergenceException;
import org.apache.commons.math.FunctionEvaluationException;
import org.apache.commons.math.complex.*;
import org.apache.commons.math.complex.Complex;
import org.apache.commons.math.complex.ComplexUtils;
/**
* Implements the <a href="http://mathworld.wolfram.com/LaguerresMethod.html">
@ -33,7 +34,7 @@ import org.apache.commons.math.complex.*;
public class LaguerreSolver extends UnivariateRealSolverImpl {
/** serializable version identifier */
static final long serialVersionUID = 5287689975005870178L;
private static final long serialVersionUID = 5287689975005870178L;
/** polynomial function to solve */
private PolynomialFunction p;
@ -117,27 +118,25 @@ public class LaguerreSolver extends UnivariateRealSolverImpl {
public double solve(double min, double max) throws ConvergenceException,
FunctionEvaluationException {
Complex c[], root[], initial, z;
// check for zeros before verifying bracketing
if (p.value(min) == 0.0) { return min; }
if (p.value(max) == 0.0) { return max; }
verifyBracketing(min, max, p);
double coefficients[] = p.getCoefficients();
c = new Complex[coefficients.length];
Complex c[] = new Complex[coefficients.length];
for (int i = 0; i < coefficients.length; i++) {
c[i] = new Complex(coefficients[i], 0.0);
}
initial = new Complex(0.5 * (min + max), 0.0);
z = solve(c, initial);
Complex initial = new Complex(0.5 * (min + max), 0.0);
Complex z = solve(c, initial);
if (isRootOK(min, max, z)) {
setResult(z.getReal(), iterationCount);
return result;
}
// solve all roots and select the one we're seeking
root = solveAll(c, initial);
Complex[] root = solveAll(c, initial);
for (int i = 0; i < root.length; i++) {
if (isRootOK(min, max, root[i])) {
setResult(root[i].getReal(), iterationCount);
@ -205,28 +204,27 @@ public class LaguerreSolver extends UnivariateRealSolverImpl {
public Complex[] solveAll(Complex coefficients[], Complex initial) throws
ConvergenceException, FunctionEvaluationException {
int i, j, n, iterationCount = 0;
Complex root[], c[], subarray[], oldc, newc;
n = coefficients.length - 1;
int n = coefficients.length - 1;
int iterationCount = 0;
if (n < 1) {
throw new IllegalArgumentException
("Polynomial degree must be positive: degree=" + n);
}
c = new Complex[n+1]; // coefficients for deflated polynomial
for (i = 0; i <= n; i++) {
Complex c[] = new Complex[n+1]; // coefficients for deflated polynomial
for (int i = 0; i <= n; i++) {
c[i] = coefficients[i];
}
// solve individual root successively
root = new Complex[n];
for (i = 0; i < n; i++) {
subarray = new Complex[n-i+1];
Complex root[] = new Complex[n];
for (int i = 0; i < n; i++) {
Complex subarray[] = new Complex[n-i+1];
System.arraycopy(c, 0, subarray, 0, subarray.length);
root[i] = solve(subarray, initial);
// polynomial deflation using synthetic division
newc = c[n-i];
for (j = n-i-1; j >= 0; j--) {
Complex newc = c[n-i];
Complex oldc = null;
for (int j = n-i-1; j >= 0; j--) {
oldc = c[j];
c[j] = newc;
newc = oldc.add(newc.multiply(root[i]));
@ -255,8 +253,6 @@ public class LaguerreSolver extends UnivariateRealSolverImpl {
public Complex solve(Complex coefficients[], Complex initial) throws
ConvergenceException, FunctionEvaluationException {
Complex z = initial, oldz, pv, dv, d2v, G, G2, H, delta, denominator;
int n = coefficients.length - 1;
if (n < 1) {
throw new IllegalArgumentException
@ -266,12 +262,22 @@ public class LaguerreSolver extends UnivariateRealSolverImpl {
Complex N1 = new Complex((double)(n-1), 0.0);
int i = 1;
oldz = new Complex(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY);
Complex pv = null;
Complex dv = null;
Complex d2v = null;
Complex G = null;
Complex G2 = null;
Complex H = null;
Complex delta = null;
Complex denominator = null;
Complex z = initial;
Complex oldz = new Complex(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY);
while (i <= maximalIterationCount) {
// Compute pv (polynomial value), dv (derivative value), and
// d2v (second derivative value) simultaneously.
pv = coefficients[n];
dv = d2v = new Complex(0.0, 0.0);
dv = Complex.ZERO;
d2v = Complex.ZERO;
for (int j = n-1; j >= 0; j--) {
d2v = dv.add(z.multiply(d2v));
dv = pv.add(z.multiply(dv));