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Reword to not reveal too much about implementation (apart from IOD of large tables). 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1169467 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Sebastian Bazley 2011-09-11 15:24:40 +00:00
parent a0b1c747b5
commit 46b35abc2c
1 changed files with 7 additions and 8 deletions
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15
src/main/java/org/apache/commons/math/util/FastMath.java
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@ -30,15 +30,14 @@ import org.apache.commons.math.exception.DimensionMismatchException;
* </p> * </p>
* <p> * <p>
* FastMath speed is achieved by relying heavily on optimizing compilers * FastMath speed is achieved by relying heavily on optimizing compilers
* to native code present in many JVM todays and use of large tables. * to native code present in many JVMs today and use of large tables.
* Precomputed literal arrays are provided in this class to speed up load * The larger tables are lazily initialised on first use, so that the setup
* time. If users prefer to compute the tables automatically at load time, * time does not penalise methods that don't need them.
* they can change the compile-time constant {@code USE_PRECOMPUTED_TABLES} * </p>
* and set it to {@code false}. This will increase class load time at first * <p>
* use, but this overhead will occur only once per run, regardless of the * Note that FastMath is
* number of subsequent calls to computation methods. Note that FastMath is
* extensively used inside Apache Commons Math, so by calling some algorithms, * extensively used inside Apache Commons Math, so by calling some algorithms,
* the one-shot overhead when the constant is set to false will occur * the overhead when the the tables need to be intialised will occur
* regardless of the end-user calling FastMath methods directly or not. * regardless of the end-user calling FastMath methods directly or not.
* Performance figures for a specific JVM and hardware can be evaluated by * Performance figures for a specific JVM and hardware can be evaluated by
* running the FastMathTestPerformance tests in the test directory of the source * running the FastMathTestPerformance tests in the test directory of the source