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NAG Toolbox: nag_sum_conjugate_hermitian_rfmt (c06gb)

Purpose

nag_sum_conjugate_hermitian_rfmt (c06gb) forms the complex conjugate of a Hermitian sequence of nn data values.
Note: this function is scheduled to be withdrawn, please see c06gb in Advice on Replacement Calls for Withdrawn/Superseded Routines..

Syntax

[x, ifail] = c06gb(x, 'n', n)
[x, ifail] = nag_sum_conjugate_hermitian_rfmt(x, 'n', n)

Description

This is a utility function for use in conjunction with nag_sum_fft_real_1d_nowork (c06ea), nag_sum_fft_hermitian_1d_nowork (c06eb), nag_sum_fft_real_1d_rfmt (c06fa) or nag_sum_fft_hermitian_1d_rfmt (c06fb) to calculate inverse discrete Fourier transforms (see the C06 Chapter Introduction).

References

None.

Parameters

Compulsory Input Parameters

1:     x(n) – double array
n, the dimension of the array, must satisfy the constraint n1n1.
If the data values zjzj are written as xj + i yjxj + i yj and if x is declared with bounds (0 : n1)(0:n-1) in the function from which nag_sum_conjugate_hermitian_rfmt (c06gb) is called, then for 0 j n / 20 j n/2, x(j)xj must contain xjxj ( = xnj= x n-j ), while for n / 2 < j n1n/2 < j n-1, x(j)xj must contain yj -y j  ( = ynj= y n-j ). In other words, x must contain the Hermitian sequence in Hermitian form. (See also Section [Real transforms] in the C06 Chapter Introduction.)

Optional Input Parameters

1:     n – int64int32nag_int scalar
Default: The dimension of the array x.
nn, the number of data values.
Constraint: n1n1.

Input Parameters Omitted from the MATLAB Interface

None.

Output Parameters

1:     x(n) – double array
The imaginary parts yjyj are negated. The real parts xjxj are not referenced.
2:     ifail – int64int32nag_int scalar
ifail = 0ifail=0 unless the function detects an error (see [Error Indicators and Warnings]).

Error Indicators and Warnings

Errors or warnings detected by the function:
  ifail = 1ifail=1
On entry,n < 1n<1.

Accuracy

Exact.

Further Comments

The time taken by nag_sum_conjugate_hermitian_rfmt (c06gb) is negligible.

Example

function nag_sum_conjugate_hermitian_rfmt_example
x = [2.483612111433092;
     -0.2659851230605639;
     -0.2576817880971343;
     -0.2563629394821892;
     0.05806233079461325;
     0.2029789655613654;
     0.5308983652332478];
[xOut, ifail] = nag_sum_conjugate_hermitian_rfmt(x)
 

xOut =

    2.4836
   -0.2660
   -0.2577
   -0.2564
   -0.0581
   -0.2030
   -0.5309


ifail =

                    0


function c06gb_example
x = [2.483612111433092;
     -0.2659851230605639;
     -0.2576817880971343;
     -0.2563629394821892;
     0.05806233079461325;
     0.2029789655613654;
     0.5308983652332478];
[xOut, ifail] = c06gb(x)
 

xOut =

    2.4836
   -0.2660
   -0.2577
   -0.2564
   -0.0581
   -0.2030
   -0.5309


ifail =

                    0



PDF version (NAG web site, 64-bit version, 64-bit version)
Chapter Contents
Chapter Introduction
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