# Copyright (c) 2002 Peter Guntert. All rights reserved.
## 7MACROS: hilbert - Hilbert transformation
##
## Usage: hilbert
##
## hilbert is a standard macro that performs a Hilbert transformation
## on the real data in order to obtain the imaginary parts.
##
## See also: ft, ift

var m

if (icmplx(active).ne.1) error "*** Error: Command requires real data."
m = n
complexify
ift
reduce 1..n/2
multiply 2 2 n
ft 2*n
reduce (n-m)/2+1..(n-m)/2+m