c06ebf

c06ebf © Numerical Algorithms Group, 2002.

Purpose

C06EBF Single 1-D Hermitian discrete Fourier transform, no extra workspace

Synopsis

[x,ifail] = c06ebf(x<,ifail>)

Description

 
 Given a Hermitian sequence of n complex data values z  (i.e., a 
                                                      j         
 sequence such that z  is real and z    is the complex conjugate 
                     0              n-j                         
 of z , for j=1,2,...,n-1) this routine calculates their discrete 
     j                                                           
 Fourier transform defined by:
 
                   n-1                  
           ^    1  --       (   2(pi)jk)
           x = --- >  z *exp(-i -------), k=0,1,...,n-1.
            k    _ --  j    (      n   )
               \/n j=0                  
 
                             1                          
 (Note the scale factor of  --- in this definition.) The 
                              _                         
                            \/n                         
                    ^                               
 transformed values x  are purely real (see also the Chapter 
                     k                              
 Introduction).
 
 To compute the inverse discrete Fourier transform defined by:
 
                          n-1                  
                  ^    1  --       (   2(pi)jk)
                  y = --- >  z *exp(+i -------),
                   k    _ --  j    (      n   )
                      \/n j=0                  
 
 this routine should be preceded by a call of C06GBF to form the 
 complex conjugates of the z .
                            j
 
 There are some restrictions on the value of n.
 

Parameters

c06ebf

Required Input Arguments:

x (:)                                 real

Optional Input Arguments:                       <Default>

ifail                                 integer  -1

Output Arguments:

x (:)                                 real
ifail                                 integer