[n,wsave]=cosqi(n,wsave);

function [n,wsave]=cosqi(n,wsave);
persistent dt fk k pih ; 

if isempty(dt), dt=0; end;
if isempty(fk), fk=0; end;
if isempty(pih), pih=0; end;
if isempty(k), k=0; end;
%***BEGIN PROLOGUE  COSQI
%***PURPOSE  Initialize a work array for COSQF and COSQB.
%***LIBRARY   SLATEC (FFTPACK)
%***CATEGORY  J1A3
%***TYPE      SINGLE PRECISION (COSQI-S)
%***KEYWORDS  COSINE FOURIER TRANSFORM, FFTPACK
%***AUTHOR  Swarztrauber, P. N., (NCAR)
%***DESCRIPTION
%
%  subroutine COSQI initializes the work array WSAVE which is used in
%  both COSQF1 and COSQB1.  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 array to be transformed.  The method
%          is most efficient when N is a product of small primes.
%
%  Output Parameter
%
%  WSAVE   a work array which must be dimensioned at least 3*N+15.
%          The same work array can be used for both COSQF1 and COSQB1
%          as long as N remains unchanged.  Different WSAVE arrays
%          are required for different values of N.  The contents of
%          WSAVE must not be changed between calls of COSQF1 or COSQB1.
%
%***REFERENCES  P. N. Swarztrauber, Vectorizing the FFTs, in Parallel
%                 Computations (G. Rodrigue, ed.), Academic Press,
%                 1982, pp. 51-83.
%***ROUTINES CALLED  RFFTI
%***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
%           (a) changing dummy array size declarations (1) to (*),
%           (b) changing references to intrinsic function FLOAT
%               to REAL, and
%           (c) changing definition of variable PIH by using
%               FORTRAN intrinsic function ATAN instead of a DATA
%               statement.
%   881128  Modified by Dick Valent to meet prologue standards.
%   890531  Changed all specific intrinsics to generic.  (WRB)
%   890531  REVISION DATE from Version 3.2
%   891214  Prologue converted to Version 4.0 format.  (BAB)
%   920501  Reformatted the REFERENCES section.  (WRB)
%***end PROLOGUE  COSQI
wsave_shape=size(wsave);wsave=reshape(wsave,1,[]);
%***FIRST EXECUTABLE STATEMENT  COSQI
pih = 2..*atan(1.);
dt = pih./n;
fk = 0.;
for k = 1 : n;
fk = fk + 1.;
wsave(k) = cos(fk.*dt);
end; k = fix(n+1);
[n,wsave(sub2ind(size(wsave),max(n+1,1)):end)]=rffti(n,wsave(sub2ind(size(wsave),max(n+1,1)):end));
wsave_shape=zeros(wsave_shape);wsave_shape(:)=wsave(1:numel(wsave_shape));wsave=wsave_shape;
end
%DECK COST