README
¶
Go bindings for FFTW v3.2.2 Maintained by Jonathan Wills: runningwild@gmail.com Feel free to email me patches, suggestions or bugs.
FFTW homepage: http://www.fftw.org/ Documentation for the latest version: http://www.fftw.org/fftw3_doc/
These bindings are incomplete, but should include enough functionality that you can do whatever transforms you need (perhaps not as easily as you would like, for now). The function definitions do not mirror exactly what is written in the docs. For example, passing arrays does not require passing the size of the arrays, and there is no need to garbage collect plans.
Usage: Here is an example of doing a simple DFT with these bindings
data := fftw.Alloc1d(64) // Similar to calling make([]complex128, 64)
forward := fftw.PlanDft1d(data, data, fftw.Forward, fftw.Estimate)
backward := fftw.PlanDft1d(data, data, fftw.Backward, fftw.Estimate)
// ... fill in data with something interesting
forward.Execute() // Transforms data, in place, to frequency domain
// ... do something interesting with data
backward.Execute() // Returns data, in place, to time domain
Calling fftw.Alloc1d(64) allows FFTW to allocate the memory so that it is properly aligned to take advantage of SIMDs. You could just use make([]complex128, size) if you want.
Installation: When installing fftw you must compile it as a shared library:
./configure --enable-shared
make
make install
Once installed properly, these bindings can be installed like so:
go get github.com/runningwild/go-fftw
Documentation
¶
Index ¶
- func Alloc1d(n int) []complex128
- func Alloc2d(n0, n1 int) [][]complex128
- func Alloc3d(n0, n1, n2 int) [][][]complex128
- func Dft1d(in, out []complex128, dir Direction, flag Flag)
- func Dft2d(in, out [][]complex128, dir Direction, flag Flag)
- func Dft3d(in, out [][][]complex128, dir Direction, flag Flag)
- func Free1d(x []complex128)
- func Free2d(x [][]complex128)
- func Free3d(x [][][]complex128)
- type Direction
- type Flag
- type Plan
- func PlanDft1d(in, out []complex128, dir Direction, flag Flag) *Plan
- func PlanDft2d(in, out [][]complex128, dir Direction, flag Flag) *Plan
- func PlanDft3d(in, out [][][]complex128, dir Direction, flag Flag) *Plan
- func PlanDftC2R1d(in []complex128, out []float64, flag Flag) *Plan
- func PlanDftR2C1d(in []float64, out []complex128, flag Flag) *Plan
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Alloc1d ¶
func Alloc1d(n int) []complex128
func Alloc2d ¶
func Alloc2d(n0, n1 int) [][]complex128
func Alloc3d ¶
func Alloc3d(n0, n1, n2 int) [][][]complex128
func Dft1d ¶
func Dft1d(in, out []complex128, dir Direction, flag Flag)
func Dft2d ¶
func Dft2d(in, out [][]complex128, dir Direction, flag Flag)
func Dft3d ¶
func Dft3d(in, out [][][]complex128, dir Direction, flag Flag)
func Free1d ¶
func Free1d(x []complex128)
func Free2d ¶
func Free2d(x [][]complex128)
func Free3d ¶
func Free3d(x [][][]complex128)
Types ¶
type Direction ¶
type Direction int
var Backward Direction = C.FFTW_BACKWARD
var Forward Direction = C.FFTW_FORWARD
type Plan ¶
type Plan struct {
// contains filtered or unexported fields
}
func PlanDftC2R1d ¶
func PlanDftC2R1d(in []complex128, out []float64, flag Flag) *Plan
Note: Executing this plan will destroy the data contained by in
func PlanDftR2C1d ¶
func PlanDftR2C1d(in []float64, out []complex128, flag Flag) *Plan
TODO: Once we can create go arrays out of pre-existing data we can do these real-to-complex and complex-to-real
transforms in-place.
The real-to-complex and complex-to-real transforms save roughly a factor of two in time and space, with the following caveats:
- The real array is of size N, the complex array is of size N/2+1.
- The output array contains only the non-redundant output, the complete output is symmetric and the last half is the complex conjugate of the first half.
- Doing a complex-to-real transform destroys the input signal.
Source Files