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Gilles edited comment on MATH-650 at 9/15/11 12:34 PM: ------------------------------------------------------- Hi Luc. Here is a "unit test" that reports timings for the set of function calls which you referred to on the ML. Before those calls, I've added a single call to "abs" (as a trivial function that does not trigger the tables initialization) in order to estimate the time taken by the "bare" initialization of "FastMath". was (Author: erans): Hi Luc. Here is a "unit test" that reports timings for the set of function calls which you referred to on the ML. Before those calls, I've added a single call to "abs" (as a trivial function that does not trigger the tables initialization) in order to estimate the time taken by the "bare" initialization of "FastMath". > FastMath has static code which slows the first access to FastMath > ----------------------------------------------------------------- > > Key: MATH-650 > URL: https://issues.apache.org/jira/browse/MATH-650 > Project: Commons Math > Issue Type: Improvement > Affects Versions: Nightly Builds > Environment: Android 2.3 (Dalvik VM with JIT) > Reporter: Alexis Robert > Priority: Minor > Attachments: FastMathLoadCheck.java, LucTestPerformance.java > > > Working on an Android application using Orekit, I've discovered that a simple > FastMath.floor() takes about 4 to 5 secs on a 1GHz Nexus One phone (only the > first time it's called). I've launched the Android profiling tool (traceview) > and the problem seems to be linked with the static portion of FastMath code > named "// Initialize tables" > The timing resulted in : > - FastMath.slowexp (40.8%) > - FastMath.expint (39.2%) > \- FastMath.quadmult() (95.6% of expint) > - FastMath.slowlog (18.2%) > Hoping that would help > Thanks! > Alexis Robert -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira