This package is a wrapper for 1D full and half complex DFT's provided by the FFTW library. Beware, this package is still under some heavy development and interface is subject to change.
package main
import (
"fmt"
"github.com/bemasher/fftw"
)
func main() {
dft := fftw.NewDFT1D(8, fftw.Forward, fftw.OutOfPlace, fftw.Measure)
defer dft.Close()
// Modifying the location of the input or output arrays will cause FFTW to
// fail. Instead, copy data into and out of arrays.
copy(dft.In, []complex128{1, 1, 1, 1, 0, 0, 0, 0})
dft.Execute()
fmt.Println(dft)
fmt.Printf("%+0.3f\n", dft.In)
fmt.Printf("%+0.3f\n", dft.Out)
}Output:
{Kind:C2C Locality:OutOfPlace PlanFlags:NA In:[8]complex128 Out:[8]complex128}
[(+1.000+0.000i) (+1.000+0.000i) (+1.000+0.000i) (+1.000+0.000i) (+0.000+0.000i) (+0.000+0.000i) (+0.000+0.000i) (+0.000+0.000i)]
[(+4.000+0.000i) (+1.000-2.414i) (+0.000+0.000i) (+1.000-0.414i) (+0.000+0.000i) (+1.000+0.414i) (+0.000+0.000i) (+1.000+2.414i)]
On Windows the library file libfftw3.a must be placed in the source directory of the package and can be generated using:
dlltool -d libfftw3-3.def -D libfftw3-3.dll -l libfftw3.a
In Debian flavored distributions installing the libfftw3-dev package is all that is required:
sudo apt-get install libfftw3-dev
The FFTW header file fftw3.h carries the following copyright notice:
Copyright (c) 2003, 2007-11 Matteo Frigo
Copyright (c) 2003, 2007-11 Massachusetts Institute of Technology
The following statement of license applies *only* to this header file,
and *not* to the other files distributed with FFTW or derived therefrom:
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.