c06 Chapter Contents
c06 Chapter Introduction
NAG Library Manual

# NAG Library Function Documentnag_conjugate_complex (c06gcc)

## 1  Purpose

nag_conjugate_complex (c06gcc) forms the complex conjugate of a sequence of $n$ data values.

## 2  Specification

 #include #include
 void nag_conjugate_complex (Integer n, double y[], NagError *fail)

## 3  Description

This is a utility function for use in conjunction with nag_fft_complex (c06ecc) to calculate inverse discrete Fourier transforms.
None.

## 5  Arguments

1:     nIntegerInput
On entry: $n$, the number of data values.
Constraint: ${\mathbf{n}}\ge 1$.
2:     y[n]doubleInput/Output
On entry: ${\mathbf{y}}\left[j\right]$ must contain the imaginary part of the $j$th data value, for $0\le j\le n-1$.
On exit: these values are negated.
3:     failNagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

## 6  Error Indicators and Warnings

NE_INT_ARG_LT
On entry, ${\mathbf{n}}=⟨\mathit{\text{value}}⟩$.
Constraint: ${\mathbf{n}}\ge 1$.

Exact.

## 8  Parallelism and Performance

Not applicable.

The time taken is negligible.

## 10  Example

This program reads in a sequence of complex data values and prints their inverse discrete Fourier transform as computed by calling nag_conjugate_complex (c06gcc), followed by nag_fft_complex (c06ecc) and nag_conjugate_complex (c06gcc) again.

### 10.1  Program Text

Program Text (c06gcce.c)

### 10.2  Program Data

Program Data (c06gcce.d)

### 10.3  Program Results

Program Results (c06gcce.r)