bitrev.m

来自「Polynomial Root Finder is a reliable and」· M 代码 · 共 30 行

function re = bitrev(rfeld)
%
% BITREV   Y = BITREV(X) returns the vector X in bitreversed order
%
%
%       Author : Raimund Meyer 15.12.87
%       Revised: Rai           26.08.88

%	Copyright (C) 1987-1991 Lehrstuhl fuer Nachrichtentechnik,
%				University of Erlangen, FRG

dim = length(rfeld);
dim1 = dim - 1;
j = 1;
for i = 1:dim1
    if i < j 
       xt       = rfeld(j);
       rfeld(j) = rfeld(i);
       rfeld(i) = xt;
    else
    end
    k = dim/2;
    while k < j
       j = j - k;
       k = k/2;
    end
    j = j + k;
end
re = rfeld;