function [n,wsave]=ezffti(n,wsave);
%***BEGIN PROLOGUE EZFFTI
%***PURPOSE Initialize a work array for EZFFTF and EZFFTB.
%***LIBRARY SLATEC (FFTPACK)
%***CATEGORY J1A1
%***TYPE SINGLE PRECISION (EZFFTI-S)
%***KEYWORDS FFTPACK, FOURIER TRANSFORM
%***AUTHOR Swarztrauber, P. N., (NCAR)
%***DESCRIPTION
%
% subroutine EZFFTI initializes the work array WSAVE which is used in
% both EZFFTF and EZFFTB. The prime factorization of N together with
% a tabulation of the trigonometric functions are computed and
% stored in WSAVE.
%
% Input Parameter
%
% N the length of the sequence to be transformed.
%
% Output Parameter
%
% WSAVE a work array which must be dimensioned at least 3*N+15.
% The same work array can be used for both EZFFTF and EZFFTB
% as long as N remains unchanged. Different WSAVE arrays
% are required for different values of N.
%
%***REFERENCES P. N. Swarztrauber, Vectorizing the FFTs, in Parallel
% Computations (G. Rodrigue, ed.), Academic Press,
% 1982, pp. 51-83.
%***ROUTINES CALLED EZFFT1
%***REVISION HISTORY (YYMMDD)
% 790601 DATE WRITTEN
% 830401 Modified to use SLATEC library source file format.
% 860115 Modified by Ron Boisvert to adhere to Fortran 77 by
% changing dummy array size declarations (1) to (*).
% 861211 REVISION DATE from Version 3.2
% 881128 Modified by Dick Valent to meet prologue standards.
% 891214 Prologue converted to Version 4.0 format. (BAB)
% 920501 Reformatted the REFERENCES section. (WRB)
%***end PROLOGUE EZFFTI
wsave_shape=size(wsave);wsave=reshape(wsave,1,[]);
%***FIRST EXECUTABLE STATEMENT EZFFTI
if( n==1 )
wsave_shape=zeros(wsave_shape);wsave_shape(:)=wsave(1:numel(wsave_shape));wsave=wsave_shape;
return;
end;
[n,dumvar2,dumvar3]=ezfft1(n,wsave(sub2ind(size(wsave),max(2.*n+1,1)):end),wsave(sub2ind(size(wsave),max(3.*n+1,1)):end)); dumvar2i=find((wsave(sub2ind(size(wsave),max(2.*n+1,1)):end))~=(dumvar2));dumvar3i=find((wsave(sub2ind(size(wsave),max(3.*n+1,1)):end))~=(dumvar3)); wsave(2.*n+1-1+dumvar2i)=dumvar2(dumvar2i); wsave(3.*n+1-1+dumvar3i)=dumvar3(dumvar3i);
wsave_shape=zeros(wsave_shape);wsave_shape(:)=wsave(1:numel(wsave_shape));wsave=wsave_shape;
end
%DECK FAC