Java FFT 工具包 jtransforms-2.3 源代码

JTransforms changelog 2.3: February 27, 2009 - Performance improvements for 3D FFT (realForwardFull() and realInverseFull() for not power-of-two sizes). - Cosmetic changes. 2.2: January 30, 2009 - Fixed race condition in 3D FFT (realForwardFull() and realInverseFull() for not power-of-two sizes). - Refactoring in ConcurrencyUtils. - Cosmetic changes. 2.1: December 12, 2008 - Added Bluestein's FFT algorithm that significantly increases the performance and fixes accuracy issues when the size of the data is a number with a large prime factor. - Added extra digits to the floating-point constants. - The root mean square (RMS) error is now computed in all accuracy classes. 2.0: November 19, 2008 - Added mixed-radix algorithms for all transforms (no more power-of-two size limitation). 1.7: August 4, 2008 - Fixed bug causing ArrayIndexOutOfBoundsException when 1D FFT transforms were run in the following order: realFrowardFull(); complexInverse(); realForwardFull(). - Added javadoc distribution. - Bzip2 is used to compress tar archives. 1.6: July 15, 2008 - Fixed bug causing error in realForwardFull() and realInverseFull() methods (3D FFT) when multiple threads were used. - Added real Discrete Hartley Transforms (DHT). 1.5: June 13, 2008 - Fixed bug causing error when setNumberOfProcessors() was called after creating new instance of a transform. - Loop unrolling in scale. - Refactoring in ConcurrencyUtils. - Improved benchmarks. 1.4: June 4, 2008 - Fixed bug causing errors in DoubleFFT_2D and FloatFFT_2D. 1.3: May 7, 2008 - From now on, realForward() followed by realInverse() returns the original data. - Added new variants of 1D transforms that allow to specify the offset in the input array. - Added new variants of constructors for 1D transforms. - Refactoring in the utility methods. - Multiple sizes of each transform are now checked in the accuracy checks. - The documentation has been updated. 1.2: January 1, 2008 - Added true multidimensional variants of 2D and 3D transforms. - Added single precision transforms. 1.1: September 23, 2007 - Added discrete sine transforms. 1.0: August 29, 2007 - Initial release.