Package org.apfloat.samples
Three different versions of an application for calculating π are
included. The simplest, Pi
runs on one
computer using one processor (and one thread) only. PiParallel
executes multiple threads in parallel and has vastly better performance
on multicore computers. Finally, PiDistributed
can use multiple separate computers for calculating pi with even
greater processing power.
As a curiosity, two applets are provided for running Pi
and PiParallel
through a graphical user
interface: PiApplet
and PiParallelApplet
,
correspondingly. These programs can also be run as standalone
Java applications: PiGUI
and PiParallelGUI
.
Compared to the C++ version of apfloat, the Java version pi calculation program is usually just as fast. Even in worst cases the Java version achieves roughly 50% of the performance of the assembleroptimized C++ versions of apfloat. Modern JVMs are nearly as efficient as optimizing C++ compilers in code generation. The advantage that JVMs have over native C++ compilers is obviously that the JVM generates optimal code for every target architecture and runtime profile automatically, from an intermediate portable binary executable format. With C++, the source code must be compiled and profiled manually for every target architecture, which can be difficult and tedious.
On multicore computers the Java parallel pi calculator is often significantly faster than the C++ parallel version. The same applies to the distributed pi calculator. Multithreaded and distributed applications are more efficient to implement in Java due to C++'s historical lack of standard libraries for threading and networking.

Interface Summary Interface Description Operation<T> Interface for implementing arbitrary operations to be executed.OperationExecutor Interface for implementing objects that can executeOperation
s.Pi.BinarySplittingSeries Terms for the binary splitting series.PiAWT.StatusIndicator Interface to indicate an error status in the application. 
Class Summary Class Description ApfloatHolder Simple JavaBean to hold oneApfloat
.BackgroundOperation<T> Class for running anOperation
in the background in a separate thread.LocalOperationExecutor Class to executeOperation
s locally.OperationServer Server for executingOperation
s from remote calls.Pi Calculates pi using four different algorithms.Pi.AbstractBinarySplittingSeries Abstract base class for the binary splitting series.Pi.BinarySplittingPiCalculator Class for implementing the binary splitting algorithm.Pi.BinarySplittingProgressIndicator Indicates progress of the pi calculation using the binary splitting algorithm.Pi.BorweinPiCalculator Calculates pi using the Borweins' quartic algorithm.Pi.ChudnovskyBinarySplittingSeries Chudnovskys' algorithm terms for the binary splitting series.Pi.ChudnovskyPiCalculator Basic class for calculating pi using the Chudnovskys' binary splitting algorithm.Pi.GaussLegendrePiCalculator Calculates pi using the GaussLegendre algorithm.Pi.RamanujanBinarySplittingSeries Ramanujan's algorithm terms for the binary splitting series.Pi.RamanujanPiCalculator Basic class for calculating pi using the Ramanujan binary splitting algorithm.PiApplet Applet for calculating pi using four different algorithms.PiAWT Graphical AWT elements for calculating pi using four different algorithms.PiDistributed Calculates pi using a cluster of servers.PiDistributed.DistributedBinarySplittingPiCalculator Distributed version of the binary splitting algorithm.PiDistributed.DistributedChudnovskyPiCalculator Class for calculating pi using the distributed Chudnovskys' binary splitting algorithm.PiDistributed.DistributedRamanujanPiCalculator Class for calculating pi using the distributed Ramanujan's binary splitting algorithm.PiDistributed.Node RemoteOperationExecutor that implements the weight property.PiGUI AWT client application for calculating pi using four different algorithms.PiParallel Calculates pi using multiple threads in parallel.PiParallel.ParallelBinarySplittingPiCalculator Parallel version of the binary splitting algorithm.PiParallel.ParallelChudnovskyPiCalculator Class for calculating pi using the parallel Chudnovskys' binary splitting algorithm.PiParallel.ParallelRamanujanPiCalculator Class for calculating pi using the parallel Ramanujan's binary splitting algorithm.PiParallel.ThreadLimitedOperation<T> Class to execute operations while settingApfloatContext.setNumberOfProcessors(int)
to some value.PiParallelApplet Applet for calculating pi using multiple threads in parallel.PiParallelAWT Graphical AWT elements for calculating pi using multiple threads in parallel.PiParallelGUI AWT client application for calculating pi using multiple threads in parallel.RemoteOperationExecutor Class to call anOperationServer
to executeOperation
s remotely.