DoubleFFT_1D

Full name Microsoft.VisualBasic.Math.SignalProcessing.FFT.DoubleFFT_1D Assembly Microsoft.VisualBasic.Math.SignalProcessing Members 14

https://github.com/cobaltblueocean/Mercury.Language.Extensions

01 Syntax

Microsoft.VisualBasic.Math.SignalProcessing.FFT.DoubleFFT_1D

02 Methods

Name	Overloads	Summary
.ctor	1	Creates new instance of DoubleFFT_1D.
ComplexForward	2	Computes 1D forward DFT of complex data leaving the result in a d Complex number is stored as two double values in sequence: the real and imaginary part, i.ed the size of the…
ComplexInverse	2	Computes 1D inverse DFT of complex data leaving the result in a d Complex number is stored as two double values in sequence: the real and imaginary part, i.ed the size of the…
RealForward	2	Computes 1D forward DFT of real data leaving the result in a d The physical layout of the output data is as follows:<br> if n is even then a[offa+2*k] = Re[k], 0<=k<n/…
RealForwardFull	2	Computes 1D forward DFT of real data leaving the result in a d This method computes the full real forward transform, i.ed you will get the same result as from complexForwar…
RealInverse	2	Computes 1D inverse DFT of real data leaving the result in a d The physical layout of the input data has to be as follows:<br> if n is even then a[2*k] = Re[k], 0<=k<n…
RealInverseFull	2	Computes 1D inverse DFT of real data leaving the result in a d This method computes the full real inverse transform, i.ed you will get the same result as from complexInvers…
RealInverse2	1

03 Members

method .ctor #

#ctor(Int32)

Creates new instance of DoubleFFT_1D.

Parameters

Name	Type	Description
`n`	`Int32`	-

method ComplexForward overload 2 #

ComplexForward(Double())

Computes 1D forward DFT of complex data leaving the result in

d Complex number is stored as two double values in sequence: the real and imaginary part, i.ed the size of the input array must be greater or equal 2*nd The physical layout of the input data has to be as follows:

a[2k] = Re[k], a[2k+1] = Im[k], 0<=k<n

Parameters

Name	Type	Description
`a`	`Double()`	data to transform

method ComplexForward #

ComplexForward(Double(), Int32)

Computes 1D forward DFT of complex data leaving the result in

a[offa+2k] = Re[k], a[offa+2k+1] = Im[k], 0<=k<n

Parameters

Name	Type	Description
`a`	`Double()`	-
`offa`	`Int32`	-

method ComplexInverse #

ComplexInverse(Double(), Boolean)

Computes 1D inverse DFT of complex data leaving the result in

a[2k] = Re[k], a[2k+1] = Im[k], 0<=k<n

Parameters

Name	Type	Description
`a`	`Double()`	data to transform
`scale`	`Boolean`	if true then scaling is performed

method ComplexInverse overload 2 #

ComplexInverse(Double(), Int32, Boolean)

Computes 1D inverse DFT of complex data leaving the result in

a[offa+2k] = Re[k], a[offa+2k+1] = Im[k], 0<=k<n

Parameters

Name Type Description

a

Double()

data to transform

offa

Int32

index of the first element in array

isScale

Boolean

if true then scaling is performed

method RealForward overload 2 #

RealForward(Double())

Computes 1D forward DFT of real data leaving the result in

d The physical layout of the output data is as follows:

if n is even then

a[2k] = Re[k], 0<=k<n/2 a[2k+1] = Im[k], 0<k<n/2 a[1] = Re[n/2]

if n is odd then

a[2k] = Re[k], 0<=k<(n+1)/2 a[2k+1] = Im[k], 0<k<(n-1)/2 a[1] = Im[(n-1)/2]

This method computes only half of the elements of the real transformd The other half satisfies the symmetry conditiond If you want the full real forward transform, use

realForwardFull

d To get back the original data, use

realInverse

on the output of this method.

Parameters

Name	Type	Description
`a`	`Double()`	data to transform

method RealForward #

RealForward(Double(), Int32)

Computes 1D forward DFT of real data leaving the result in

d The physical layout of the output data is as follows:

if n is even then

a[offa+2k] = Re[k], 0<=k<n/2 a[offa+2k+1] = Im[k], 0<k<n/2 a[offa+1] = Re[n/2]

if n is odd then

a[offa+2k] = Re[k], 0<=k<(n+1)/2 a[offa+2k+1] = Im[k], 0<k<(n-1)/2 a[offa+1] = Im[(n-1)/2]

This method computes only half of the elements of the real transformd The other half satisfies the symmetry conditiond If you want the full real forward transform, use

realForwardFull

d To get back the original data, use

realInverse

on the output of this method.

Parameters

Name Type Description

a

Double()

data to transform

offa

Int32

index of the first element in array

method RealForwardFull overload 2 #

RealForwardFull(Double())

Computes 1D forward DFT of real data leaving the result in

d This method computes the full real forward transform, i.ed you will get the same result as from

complexForward

called with all imaginary parts equal 0d Because the result is stored in

, the size of the input array must greater or equal 2*n, with only the first n elements filled with real datad To get back the original data, use

complexInverse

on the output of this method.

Parameters

Name	Type	Description
`a`	`Double()`	-

method RealForwardFull #

RealForwardFull(Double(), Int32)

Computes 1D forward DFT of real data leaving the result in

d This method computes the full real forward transform, i.ed you will get the same result as from

complexForward

called with all imaginary part equal 0d Because the result is stored in

, the size of the input array must greater or equal 2*n, with only the first n elements filled with real datad To get back the original data, use

complexInverse

on the output of this method.

Parameters

Name	Type	Description
`a`	`Double()`	-
`offa`	`Int32`	-

method RealInverse #

RealInverse(Double(), Boolean)

Computes 1D inverse DFT of real data leaving the result in

d The physical layout of the input data has to be as follows:

if n is even then

a[2k] = Re[k], 0<=k<n/2 a[2k+1] = Im[k], 0<k<n/2 a[1] = Re[n/2]

if n is odd then

a[2k] = Re[k], 0<=k<(n+1)/2 a[2k+1] = Im[k], 0<k<(n-1)/2 a[1] = Im[(n-1)/2]

This method computes only half of the elements of the real transformd The other half satisfies the symmetry conditiond If you want the full real inverse transform, use

realInverseFull

Parameters

Name	Type	Description
`a`	`Double()`	data to transform
`scale`	`Boolean`	if true then scaling is performed

method RealInverse overload 2 #

RealInverse(Double(), Int32, Boolean)

Computes 1D inverse DFT of real data leaving the result in

d The physical layout of the input data has to be as follows:

if n is even then

a[offa+2k] = Re[k], 0<=k<n/2 a[offa+2k+1] = Im[k], 0<k<n/2 a[offa+1] = Re[n/2]

if n is odd then

a[offa+2k] = Re[k], 0<=k<(n+1)/2 a[offa+2k+1] = Im[k], 0<k<(n-1)/2 a[offa+1] = Im[(n-1)/2]

This method computes only half of the elements of the real transformd The other half satisfies the symmetry conditiond If you want the full real inverse transform, use

realInverseFull

Parameters

Name Type Description

a

Double()

data to transform

offa

Int32

index of the first element in array

isScale

Boolean

if true then scaling is performed

method RealInverseFull #

RealInverseFull(Double(), Boolean)

Computes 1D inverse DFT of real data leaving the result in

d This method computes the full real inverse transform, i.ed you will get the same result as from

complexInverse

called with all imaginary part equal 0d Because the result is stored in

, the size of the input array must greater or equal 2*n, with only the first n elements filled with real data.

Parameters

Name	Type	Description
`a`	`Double()`	-
`isScale`	`Boolean`	if true then scaling is performed

method RealInverseFull overload 2 #

RealInverseFull(Double(), Int32, Boolean)

Computes 1D inverse DFT of real data leaving the result in

d This method computes the full real inverse transform, i.ed you will get the same result as from

complexInverse

called with all imaginary part equal 0d Because the result is stored in

, the size of the input array must greater or equal 2*n, with only the first n elements filled with real data.

Parameters

Name Type Description

a

Double()

data to transform

offa

Int32

index of the first element in array

isScale

Boolean

if true then scaling is performed

method RealInverse2 #

RealInverse2(Double(), Int32, Boolean)