/*
* 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.math4.util;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.math4.exception.MathArithmeticException;
import org.apache.commons.math4.util.FastMath;
import org.apache.commons.numbers.core.Precision;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
/**
* Test to compare FastMath results against StrictMath results for boundary values.
* <p>
* Running all tests independently: <br>
* {@code mvn test -Dtest=FastMathStrictComparisonTest}<br>
* or just run tests against a single method (e.g. scalb):<br>
* {@code mvn test -Dtest=FastMathStrictComparisonTest -DargLine="-DtestMethod=scalb"}
*/
@SuppressWarnings("boxing")
@RunWith(Parameterized.class)
public class FastMathStrictComparisonTest {
// Values which often need special handling
private static final Double[] DOUBLE_SPECIAL_VALUES = {
-0.0, +0.0, // 1,2
Double.NaN, // 3
Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, // 4,5
-Double.MAX_VALUE, Double.MAX_VALUE, // 6,7
// decreasing order of absolute value to help catch first failure
-Precision.EPSILON, Precision.EPSILON, // 8,9
-Precision.SAFE_MIN, Precision.SAFE_MIN, // 10,11
-Double.MIN_VALUE, Double.MIN_VALUE, // 12,13
};
private static final Float [] FLOAT_SPECIAL_VALUES = {
-0.0f, +0.0f, // 1,2
Float.NaN, // 3
Float.NEGATIVE_INFINITY, Float.POSITIVE_INFINITY, // 4,5
Float.MIN_VALUE, Float.MAX_VALUE, // 6,7
-Float.MIN_VALUE, -Float.MAX_VALUE, // 8,9
};
private static final Object [] LONG_SPECIAL_VALUES = {
-1,0,1, // 1,2,3
Long.MIN_VALUE, Long.MAX_VALUE, // 4,5
};
private static final Object[] INT_SPECIAL_VALUES = {
-1,0,1, // 1,2,3
Integer.MIN_VALUE, Integer.MAX_VALUE, // 4,5
};
private final Method mathMethod;
private final Method fastMethod;
private final Type[] types;
private final Object[][] valueArrays;
public FastMathStrictComparisonTest(Method m, Method f, Type[] types, Object[][] data) throws Exception{
this.mathMethod=m;
this.fastMethod=f;
this.types=types;
this.valueArrays=data;
}
@Test
public void test1() throws Exception{
setupMethodCall(mathMethod, fastMethod, types, valueArrays);
}
private static boolean isNumber(Double d) {
return !(d.isInfinite() || d.isNaN());
}
private static boolean isNumber(Float f) {
return !(f.isInfinite() || f.isNaN());
}
private static void reportFailedResults(Method mathMethod, Object[] params, Object expected, Object actual, int[] entries){
final String methodName = mathMethod.getName();
String format = null;
long actL=0;
long expL=0;
if (expected instanceof Double) {
Double exp = (Double) expected;
Double act = (Double) actual;
if (isNumber(exp) && isNumber(act) && exp != 0) { // show difference as hex
actL = Double.doubleToLongBits(act);
expL = Double.doubleToLongBits(exp);
if (Math.abs(actL-expL)==1) {
// Not 100% sure off-by-one errors are allowed everywhere, so only allow for these methods
if (methodName.equals("toRadians") || methodName.equals("atan2")) {
return;
}
}
format = "%016x";
}
} else if (expected instanceof Float ){
Float exp = (Float) expected;
Float act = (Float) actual;
if (isNumber(exp) && isNumber(act) && exp != 0) { // show difference as hex
actL = Float.floatToIntBits(act);
expL = Float.floatToIntBits(exp);
format = "%08x";
}
}
StringBuilder sb = new StringBuilder();
sb.append(mathMethod.getReturnType().getSimpleName());
sb.append(" ");
sb.append(methodName);
sb.append("(");
String sep = "";
for(Object o : params){
sb.append(sep);
sb.append(o);
sep=", ";
}
sb.append(") expected ");
if (format != null){
sb.append(String.format(format, expL));
} else {
sb.append(expected);
}
sb.append(" actual ");
if (format != null){
sb.append(String.format(format, actL));
} else {
sb.append(actual);
}
sb.append(" entries ");
sb.append(Arrays.toString(entries));
String message = sb.toString();
final boolean fatal = true;
if (fatal) {
Assert.fail(message);
} else {
System.out.println(message);
}
}
private static void callMethods(Method mathMethod, Method fastMethod,
Object[] params, int[] entries) throws IllegalAccessException {
try {
Object expected;
try {
expected = mathMethod.invoke(mathMethod, params);
} catch (InvocationTargetException ite) {
expected = ite.getCause();
}
Object actual;
try {
actual = fastMethod.invoke(mathMethod, params);
} catch (InvocationTargetException ite) {
actual = ite.getCause();
}
if (expected instanceof ArithmeticException) {
Assert.assertEquals(MathArithmeticException.class, actual.getClass());
} else if (!expected.equals(actual)) {
reportFailedResults(mathMethod, params, expected, actual, entries);
}
} catch (IllegalArgumentException e) {
Assert.fail(mathMethod+" "+e);
}
}
private static void setupMethodCall(Method mathMethod, Method fastMethod,
Type[] types, Object[][] valueArrays) throws Exception {
Object[] params = new Object[types.length];
int entry1 = 0;
int[] entries = new int[types.length];
for(Object d : valueArrays[0]) {
entry1++;
params[0] = d;
entries[0] = entry1;
if (params.length > 1){
int entry2 = 0;
for(Object d1 : valueArrays[1]) {
entry2++;
params[1] = d1;
entries[1] = entry2;
callMethods(mathMethod, fastMethod, params, entries);
}
} else {
callMethods(mathMethod, fastMethod, params, entries);
}
}
}
@Parameters
public static List<Object[]> data() throws Exception {
String singleMethod = System.getProperty("testMethod");
List<Object[]> list = new ArrayList<>();
for(Method mathMethod : StrictMath.class.getDeclaredMethods()) {
method:
if (Modifier.isPublic(mathMethod.getModifiers())){// Only test public methods
Type []types = mathMethod.getGenericParameterTypes();
if (types.length >=1) { // Only check methods with at least one parameter
try {
// Get the corresponding FastMath method
Method fastMethod = FastMath.class.getDeclaredMethod(mathMethod.getName(), (Class[]) types);
if (Modifier.isPublic(fastMethod.getModifiers())) { // It must be public too
if (singleMethod != null && !fastMethod.getName().equals(singleMethod)) {
break method;
}
Object [][] values = new Object[types.length][];
int index = 0;
for(Type t : types) {
if (t.equals(double.class)){
values[index]=DOUBLE_SPECIAL_VALUES;
} else if (t.equals(float.class)) {
values[index]=FLOAT_SPECIAL_VALUES;
} else if (t.equals(long.class)) {
values[index]=LONG_SPECIAL_VALUES;
} else if (t.equals(int.class)) {
values[index]=INT_SPECIAL_VALUES;
} else {
System.out.println("Cannot handle class "+t+" for "+mathMethod);
break method;
}
index++;
}
// System.out.println(fastMethod);
/*
* The current implementation runs each method as a separate test.
* Could be amended to run each value as a separate test
*/
list.add(new Object[]{mathMethod, fastMethod, types, values});
// setupMethodCall(mathMethod, fastMethod, params, data);
} else {
System.out.println("Cannot find public FastMath method corresponding to: "+mathMethod);
}
} catch (NoSuchMethodException e) {
System.out.println("Cannot find FastMath method corresponding to: "+mathMethod);
}
}
}
}
return list;
}
}