From 3ad5595706a90adc920105b5c486e4fc0db6d497 Mon Sep 17 00:00:00 2001
From: Luc Maisonobe <luc@apache.org>
Date: Mon, 11 Mar 2013 08:37:12 +0000
Subject: [PATCH] Removed the log10 declaration in RealFieldElement interface.

This method introduced a binary incompatibility as one implementing
class (Dfp) did not have the proper return type and had to be changed.
The method will be added back in the interface for 4.0, when it will be
allowed to change the return type for Dfp.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1455053 13f79535-47bb-0310-9956-ffa450edef68
---
 .../commons/math3/RealFieldElement.java       | 10 ++++++----
 .../differentiation/DerivativeStructure.java  |  4 +++-
 .../org/apache/commons/math3/dfp/Dfp.java     | 20 +++++++++++++++----
 .../apache/commons/math3/util/Decimal64.java  |  4 +++-
 .../ExtendedFieldElementAbstractTest.java     | 14 +++++++------
 5 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/src/main/java/org/apache/commons/math3/RealFieldElement.java b/src/main/java/org/apache/commons/math3/RealFieldElement.java
index e9d041f53..420eca40f 100644
--- a/src/main/java/org/apache/commons/math3/RealFieldElement.java
+++ b/src/main/java/org/apache/commons/math3/RealFieldElement.java
@@ -205,10 +205,12 @@ public interface RealFieldElement<T> extends FieldElement<T> {
      */
     T log1p();
 
-    /** Base 10 logarithm.
-     * @return base 10 logarithm of the instance
-     */
-    T log10();
+//    TODO: add this method in 4.0, as it is not possible to do it in 3.2
+//          due to incompatibility of the return type in the Dfp class
+//    /** Base 10 logarithm.
+//     * @return base 10 logarithm of the instance
+//     */
+//    T log10();
 
     /** Cosine operation.
      * @return cos(this)
diff --git a/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java b/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
index fef9a42b0..dd7f98e42 100644
--- a/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
+++ b/src/main/java/org/apache/commons/math3/analysis/differentiation/DerivativeStructure.java
@@ -621,7 +621,9 @@ public class DerivativeStructure implements RealFieldElement<DerivativeStructure
         return result;
     }
 
-    /** {@inheritDoc} */
+    /** Base 10 logarithm.
+     * @return base 10 logarithm of the instance
+     */
     public DerivativeStructure log10() {
         final DerivativeStructure result = new DerivativeStructure(compiler);
         compiler.log10(data, 0, result.data, 0);
diff --git a/src/main/java/org/apache/commons/math3/dfp/Dfp.java b/src/main/java/org/apache/commons/math3/dfp/Dfp.java
index 0787c0f1b..b8127ed9f 100644
--- a/src/main/java/org/apache/commons/math3/dfp/Dfp.java
+++ b/src/main/java/org/apache/commons/math3/dfp/Dfp.java
@@ -2665,13 +2665,25 @@ public class Dfp implements RealFieldElement<Dfp> {
         return DfpMath.log(this.add(getOne()));
     }
 
-    /** {@inheritDoc}
-     * @since 3.2
+//  TODO: deactivate this implementation (and return type) in 4.0
+    /** Get the exponent of the greatest power of 10 that is less than or equal to abs(this).
+     *  @return integer base 10 logarithm
+     *  @deprecated as of 3.2, replaced by {@link #intLog10()}, in 4.0 the return type
+     *  will be changed to Dfp
      */
-    public Dfp log10() {
-        return DfpMath.log(this).divide(DfpMath.log(newInstance(10)));
+    @Deprecated
+    public int log10()  {
+        return intLog10();
     }
 
+//    TODO: activate this implementation (and return type) in 4.0
+//    /** {@inheritDoc}
+//     * @since 3.2
+//     */
+//    public Dfp log10() {
+//        return DfpMath.log(this).divide(DfpMath.log(newInstance(10)));
+//    }
+
     /** {@inheritDoc}
      * @since 3.2
      */
diff --git a/src/main/java/org/apache/commons/math3/util/Decimal64.java b/src/main/java/org/apache/commons/math3/util/Decimal64.java
index f3cc616da..1e3e12fe1 100644
--- a/src/main/java/org/apache/commons/math3/util/Decimal64.java
+++ b/src/main/java/org/apache/commons/math3/util/Decimal64.java
@@ -442,7 +442,9 @@ public class Decimal64 extends Number
         return new Decimal64(FastMath.log1p(value));
     }
 
-    /** {@inheritDoc} */
+    /** Base 10 logarithm.
+     * @return base 10 logarithm of the instance
+     */
     public Decimal64 log10() {
         return new Decimal64(FastMath.log10(value));
     }
diff --git a/src/test/java/org/apache/commons/math3/ExtendedFieldElementAbstractTest.java b/src/test/java/org/apache/commons/math3/ExtendedFieldElementAbstractTest.java
index fab4618b9..76e9cd548 100644
--- a/src/test/java/org/apache/commons/math3/ExtendedFieldElementAbstractTest.java
+++ b/src/test/java/org/apache/commons/math3/ExtendedFieldElementAbstractTest.java
@@ -312,12 +312,14 @@ public abstract class ExtendedFieldElementAbstractTest<T extends RealFieldElemen
         }
     }
 
-    @Test
-    public void testLog10() {
-        for (double x = -0.9; x < 0.9; x += 0.05) {
-            checkRelative(FastMath.log10(x), build(x).log10());
-        }
-    }
+//  TODO: add this test in 4.0, as it is not possible to do it in 3.2
+//  due to incompatibility of the return type in the Dfp class
+//    @Test
+//    public void testLog10() {
+//        for (double x = -0.9; x < 0.9; x += 0.05) {
+//            checkRelative(FastMath.log10(x), build(x).log10());
+//        }
+//    }
 
     @Test
     public void testAbs() {