Author: nick
Date: Tue Apr 15 17:17:27 2008
New Revision: 648463
URL: http://svn.apache.org/viewvc?rev=648463&view=rev
Log:
Add MoreMath class
Added:
commons/sandbox/me/trunk/src/org/apache/commons/me/lang/
commons/sandbox/me/trunk/src/org/apache/commons/me/math/MoreMath.java
(with props)
commons/sandbox/me/trunk/test-src/org/apache/commons/me/lang/
commons/sandbox/me/trunk/test-src/org/apache/commons/me/math/TestMoreMath.java
(with props)
Modified:
commons/sandbox/me/trunk/build-lib/ (props changed)
commons/sandbox/me/trunk/src/org/apache/commons/me/util/ArrayHelper.java
Propchange: commons/sandbox/me/trunk/build-lib/
------------------------------------------------------------------------------
--- svn:ignore (added)
+++ svn:ignore Tue Apr 15 17:17:27 2008
@@ -0,0 +1,3 @@
+junit-3.8.1.jar
+*.class
+*.swp
Added: commons/sandbox/me/trunk/src/org/apache/commons/me/math/MoreMath.java
URL:
http://svn.apache.org/viewvc/commons/sandbox/me/trunk/src/org/apache/commons/me/math/MoreMath.java?rev=648463&view=auto
==============================================================================
--- commons/sandbox/me/trunk/src/org/apache/commons/me/math/MoreMath.java
(added)
+++ commons/sandbox/me/trunk/src/org/apache/commons/me/math/MoreMath.java Tue
Apr 15 17:17:27 2008
@@ -0,0 +1,160 @@
+/* ====================================================================
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+==================================================================== */
+package org.apache.commons.me.math;
+
+/**
+ * Fills in holes in the JavaME math libraries
+ */
+public class MoreMath {
+ /* Define some of our constants */
+ static final double PI = java.lang.Math.PI;
+ static final double HALF_PI = 1.5707963267948966135;
+ static final double NaN = (0.0/0.0);
+
+ // Various numbers based on the square root of two
+ static final double SQRT2 = 1.414213562373095048802e0;
+ static final double SQRT2_P1 = 2.414213562373095048802e0;
+ static final double SQRT2_M1 = 0.414213562373095048802e0;
+
+ // These are all used for the atan function
+ static final double p4 = 16.1536412982230228262;
+ static final double p3 = 268.42548195503973794141;
+ static final double p2 = 1153.0293515404850115428136;
+ static final double p1 = 1780.40631643319697105464587;
+ static final double p0 = 896.78597403663861959987488;
+ static final double q4 = 58.95697050844462222791;
+ static final double q3 = 536.265374031215315104235;
+ static final double q2 = 1666.7838148816337184521798;
+ static final double q1 = 2079.33497444540981287275926;
+ static final double q0 = 896.78597403663861962481162;
+
+ /**
+ * Implement the asin (arc-sine) function
+ */
+ public static double asin(double val) {
+ double work;
+ int sign;
+
+ // Work on positive numbers
+ sign = 0;
+ if(val < 0) {
+ val = -val;
+ sign++;
+ }
+
+ // Can't take the asin of a number >1 or <-1
+ if(val > 1) return NaN;
+
+ // Calculate
+ work = java.lang.Math.sqrt(1 - val*val);
+ if(val > 0.7) {
+ work = HALF_PI - atan(work/val);
+ } else {
+ work = atan(val/work);
+ }
+
+ // Fix the sign as needed
+ if(sign > 0) {
+ work = -work;
+ }
+ return work;
+ }
+
+ /**
+ * Implement the acos (arc-cosine) function
+ */
+ public static double acos(double val) {
+ // Can't take the acos of a number >1 or <-1
+ if(val > 1 || val < -1) return NaN;
+
+ // Can implement acos off asin
+ return HALF_PI - asin(val);
+ }
+
+ /**
+ * Implement the atan (arc-tangent) function
+ */
+ public static double atan(double val) {
+ if(val > 0) {
+ return scaling_atan(val);
+ }
+ return -scaling_atan( -val );
+ }
+
+ /**
+ * Implement the atan2 function, which
+ * converts rectangular coordinates (x, y) to polar (r, theta)
+ */
+ public static double atan2(double val1, double val2) {
+ if(val1+val2 == val1) {
+ if(val1 >= 0) {
+ return HALF_PI;
+ }
+ return -HALF_PI;
+ }
+
+ val1 = atan(val1/val2);
+ if(val2 < 0) {
+ if(val1 <= 0) {
+ return val1 + PI;
+ }
+ return val1 - PI;
+ }
+ return val1;
+ }
+
+ /**
+ * Takes a positive value between 0 and
+ * PI, scales it into the range 0 to 0.414,
+ * and calls reducted_atan on it.
+ */
+ private static double scaling_atan(double val) {
+ if(val < SQRT2_M1) {
+ // Already in right range, use
+ return reducted_atan(val);
+ }
+ if(val > SQRT2_P1) {
+ // Long way out of range, invert
+ return HALF_PI - reducted_atan(1/val);
+ }
+ // Between sqrt(2)-1 and sqrt(2)+1
+ // Scale slightly
+ return HALF_PI/2 + reducted_atan((val-1)/(val+1));
+ }
+
+ /**
+ * Performs the atan function, but only on a limited
+ * range of inputs.
+ * Works for the range -0.414 to +0.414
+ */
+ private static double reducted_atan(double val) {
+ double val_sq, value;
+
+ val_sq = val*val;
+ value = ((((p4*val_sq + p3)*val_sq + p2)*val_sq + p1)*val_sq +
p0);
+ value = value / (((((val_sq + q4)*val_sq + q3)*val_sq +
q2)*val_sq + q1)*val_sq + q0);
+ return value*val;
+ }
+
+
+ /**
+ * Empty constructor - largely un-used as
+ * methods are static
+ */
+ public MoreMath() {
+ }
+}
Propchange:
commons/sandbox/me/trunk/src/org/apache/commons/me/math/MoreMath.java
------------------------------------------------------------------------------
svn:eol-style = native
Modified:
commons/sandbox/me/trunk/src/org/apache/commons/me/util/ArrayHelper.java
URL:
http://svn.apache.org/viewvc/commons/sandbox/me/trunk/src/org/apache/commons/me/util/ArrayHelper.java?rev=648463&r1=648462&r2=648463&view=diff
==============================================================================
--- commons/sandbox/me/trunk/src/org/apache/commons/me/util/ArrayHelper.java
(original)
+++ commons/sandbox/me/trunk/src/org/apache/commons/me/util/ArrayHelper.java
Tue Apr 15 17:17:27 2008
@@ -1,3 +1,19 @@
+/* ====================================================================
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+==================================================================== */
package org.apache.commons.me.util;
/**
Added:
commons/sandbox/me/trunk/test-src/org/apache/commons/me/math/TestMoreMath.java
URL:
http://svn.apache.org/viewvc/commons/sandbox/me/trunk/test-src/org/apache/commons/me/math/TestMoreMath.java?rev=648463&view=auto
==============================================================================
---
commons/sandbox/me/trunk/test-src/org/apache/commons/me/math/TestMoreMath.java
(added)
+++
commons/sandbox/me/trunk/test-src/org/apache/commons/me/math/TestMoreMath.java
Tue Apr 15 17:17:27 2008
@@ -0,0 +1,65 @@
+/* ====================================================================
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+==================================================================== */
+package org.apache.commons.me.math;
+
+import junit.framework.TestCase;
+
+/**
+ * Tests for the More Maths functions
+ */
+public class TestMoreMath extends TestCase {
+ private static double[] testArcVals = new double[] {
+ 0, 0.1, 0.11, 0.5, 0.9, 1.0, -0.1, -0.5, -1.0
+ };
+ private static double[] testMoreArcVals = new double[] {
+ 1.1, 10, 20, 100, 1000, Math.PI, -1.4, -20
+ };
+
+ public void testASin() {
+ for(int i=0; i<testArcVals.length; i++) {
+ assertEquals(
+ MoreMath.asin(testArcVals[i]),
Math.asin(testArcVals[i]), 0.0001
+ );
+ }
+ assertTrue(Double.isNaN( MoreMath.asin( 1.1 ) ));
+ assertTrue(Double.isNaN( MoreMath.asin( -1.1 ) ));
+ }
+
+ public void testACos() {
+ for(int i=0; i<testArcVals.length; i++) {
+ assertEquals(
+ MoreMath.acos(testArcVals[i]),
Math.acos(testArcVals[i]), 0.0001
+ );
+ }
+ assertTrue(Double.isNaN( MoreMath.acos( 1.1 ) ));
+ assertTrue(Double.isNaN( MoreMath.acos( -1.1 ) ));
+ }
+
+ public void testATan() {
+ for(int i=0; i<testArcVals.length; i++) {
+ assertEquals(
+ MoreMath.atan(testArcVals[i]),
Math.atan(testArcVals[i]), 0.0001
+ );
+ }
+ // atan can go over 1, as tan is crazy like that
+ for(int i=0; i<testMoreArcVals.length; i++) {
+ assertEquals(
+ MoreMath.atan(testMoreArcVals[i]),
Math.atan(testMoreArcVals[i]), 0.0001
+ );
+ }
+ }
+}
Propchange:
commons/sandbox/me/trunk/test-src/org/apache/commons/me/math/TestMoreMath.java
------------------------------------------------------------------------------
svn:eol-style = native
