[n,r,wsave]=rfftf(n,r,wsave);

function [n,r,wsave]=rfftf(n,r,wsave);
%***BEGIN PROLOGUE  RFFTF
%***SUBSIDIARY
%***PURPOSE  Compute the forward transform of a real, periodic sequence.
%***LIBRARY   SLATEC (FFTPACK)
%***CATEGORY  J1A1
%***TYPE      SINGLE PRECISION (RFFTF-S, CFFTF-C)
%***KEYWORDS  FFTPACK, FOURIER TRANSFORM
%***AUTHOR  Swarztrauber, P. N., (NCAR)
%***DESCRIPTION
%
%   ********************************************************************
%   *   NOTICE   NOTICE   NOTICE   NOTICE   NOTICE   NOTICE   NOTICE   *
%   ********************************************************************
%   *                                                                  *
%   *   This routine uses non-standard Fortran 77 constructs and will  *
%   *   be removed from the library at a future date.  You are         *
%   *   requested to use RFFTF1.                                       *
%   *                                                                  *
%   ********************************************************************
%
%   subroutine RFFTF computes the Fourier coefficients of a real
%   periodic sequence (Fourier analysis).  The transform is defined
%   below at output parameter R.
%
%   Input Arguments
%
%   N       the length of the array R to be transformed.  The method
%           is most efficient when N is a product of small primes.
%           N may change so long as different work arrays are provided.
%
%   R       a real array of length N which contains the sequence
%           to be transformed.
%
%   WSAVE   a work array which must be dimensioned at least 2*N+15
%           in the program that calls RFFTF.  The WSAVE array must be
%           initialized by calling subroutine RFFTI, and a different
%           WSAVE array must be used for each different value of N.
%           This initialization does not have to be repeated so long as
%           remains unchanged.  Thus subsequent transforms can be
%           obtained faster than the first.  Moreover, the same WSAVE
%           array can be used by RFFTF and RFFTB as long as N remains
%           unchanged.
%
%   Output Argument
%
%   R       R(1) = the sum from I=1 to I=N of R(I)
%
%           If N is even set L = N/2; if N is odd set L = (N+1)/2
%
%             then for K = 2,...,L
%
%                R(2*K-2) = the sum from I = 1 to I = N of
%
%                     R(I)*COS((K-1)*(I-1)*2*PI/N)
%
%                R(2*K-1) = the sum from I = 1 to I = N of
%
%                    -R(I)*SIN((K-1)*(I-1)*2*PI/N)
%
%           If N is even
%
%                R(N) = the sum from I = 1 to I = N of
%
%                     (-1)**(I-1)*R(I)
%
%   Note:  This transform is unnormalized since a call of RFFTF
%          followed by a call of RFFTB will multiply the input
%          sequence by N.
%
%   WSAVE  contains results which must not be destroyed between
%          calls of RFFTF or RFFTB.
%
%***REFERENCES  P. N. Swarztrauber, Vectorizing the FFTs, in Parallel
%                 Computations (G. Rodrigue, ed.), Academic Press,
%                 1982, pp. 51-83.
%***ROUTINES CALLED  RFFTF1
%***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)
%   900131  Routine changed from user-callable to subsidiary
%           because of non-standard Fortran 77 arguments in the
%           call to CFFTB1.  (WRB)
%   920501  Reformatted the REFERENCES section.  (WRB)
%***end PROLOGUE  RFFTF

r_shape=size(r);r=reshape(r,1,[]);
wsave_shape=size(wsave);wsave=reshape(wsave,1,[]);
%***FIRST EXECUTABLE STATEMENT  RFFTF
if( n==1 )
r_shape=zeros(r_shape);r_shape(:)=r(1:numel(r_shape));r=r_shape;
wsave_shape=zeros(wsave_shape);wsave_shape(:)=wsave(1:numel(wsave_shape));wsave=wsave_shape;
return;
end;
[n,r,wsave,dumvar4,dumvar5]=rfftf1(n,r,wsave,wsave(sub2ind(size(wsave),max(n+1,1)):end),wsave(sub2ind(size(wsave),max(2.*n+1,1)):end));   dumvar4i=find((wsave(sub2ind(size(wsave),max(n+1,1)):end))~=(dumvar4));dumvar5i=find((wsave(sub2ind(size(wsave),max(2.*n+1,1)):end))~=(dumvar5));   wsave(n+1-1+dumvar4i)=dumvar4(dumvar4i); wsave(2.*n+1-1+dumvar5i)=dumvar5(dumvar5i); 
r_shape=zeros(r_shape);r_shape(:)=r(1:numel(r_shape));r=r_shape;
wsave_shape=zeros(wsave_shape);wsave_shape(:)=wsave(1:numel(wsave_shape));wsave=wsave_shape;
end
%DECK RFFTI1