[a,lda,n,kpvt,b]=chisl(a,lda,n,kpvt,b);

function [a,lda,n,kpvt,b]=chisl(a,lda,n,kpvt,b);
%***BEGIN PROLOGUE  CHISL
%***PURPOSE  Solve the complex Hermitian system using factors obtained
%            from CHIFA.
%***LIBRARY   SLATEC (LINPACK)
%***CATEGORY  D2D1A
%***TYPE      COMPLEX (SSISL-S, DSISL-D, CHISL-C, CSISL-C)
%***KEYWORDS  HERMITIAN, LINEAR ALGEBRA, LINPACK, MATRIX, SOLVE
%***AUTHOR  Bunch, J., (UCSD)
%***DESCRIPTION
%
%     CHISL solves the complex Hermitian system
%     A * X = B
%     using the factors computed by CHIFA.
%
%     On Entry
%
%        A       COMPLEX(LDA,N)
%                the output from CHIFA.
%
%        LDA     INTEGER
%                the leading dimension of the array  A .
%
%        N       INTEGER
%                the order of the matrix  A .
%
%        KVPT    INTEGER(N)
%                the pivot vector from CHIFA.
%
%        B       COMPLEX(N)
%                the right hand side vector.
%
%     On Return
%
%        B       the solution vector  X .
%
%     Error Condition
%
%        A division by zero may occur if  CHICO  has set RCOND .EQ. 0.0
%        or  CHIFA  has set INFO .NE. 0  .
%
%     To compute  INVERSE(A) * C  where  C  is a matrix
%     with  P  columns
%           CALL CHIFA(A,LDA,N,KVPT,INFO)
%           IF (INFO .NE. 0) GO TO ...
%           DO 10 J = 1, p
%              CALL CHISL(A,LDA,N,KVPT,C(1,J))
%        10 CONTINUE
%
%***REFERENCES  J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
%                 Stewart, LINPACK Users' Guide, SIAM, 1979.
%***ROUTINES CALLED  CAXPY, CDOTC
%***REVISION HISTORY  (YYMMDD)
%   780814  DATE WRITTEN
%   890531  Changed all specific intrinsics to generic.  (WRB)
%   890831  Modified array declarations.  (WRB)
%   891107  Modified routine equivalence list.  (WRB)
%   891107  REVISION DATE from Version 3.2
%   891214  Prologue converted to Version 4.0 format.  (BAB)
%   900326  Removed duplicate information from DESCRIPTION section.
%           (WRB)
%   920501  Reformatted the REFERENCES section.  (WRB)
%***end PROLOGUE  CHISL
persistent ak akm1 bk bkm1 denom k kp temp ; 

kpvt_shape=size(kpvt);kpvt=reshape(kpvt,1,[]);
a_shape=size(a);a=reshape([a(:).',zeros(1,ceil(numel(a)./prod([lda])).*prod([lda])-numel(a))],lda,[]);
b_shape=size(b);b=reshape(b,1,[]);
%
if isempty(ak), ak=0; end;
if isempty(akm1), akm1=0; end;
if isempty(bk), bk=0; end;
if isempty(bkm1), bkm1=0; end;
if isempty(denom), denom=0; end;
if isempty(temp), temp=0; end;
if isempty(k), k=0; end;
if isempty(kp), kp=0; end;
%
%     LOOP BACKWARD APPLYING THE TRANSFORMATIONS AND
%     D INVERSE TO B.
%
%***FIRST EXECUTABLE STATEMENT  CHISL
k = fix(n);
while( k~=0 );
if( kpvt(k)<0 )
%
%           2 X 2 PIVOT BLOCK.
%
if( k~=2 )
kp = fix(abs(kpvt(k)));
if( kp~=k-1 )
%
%                 INTERCHANGE.
%
temp = b(k-1);
b(k-1) = b(kp);
b(kp) = temp;
end;
%
%              APPLY THE TRANSFORMATION.
%
[dumvar1,dumvar2,a(sub2ind(size(a),1,k):end),dumvar4,dumvar5]=caxpy(k-2,b(k),a(sub2ind(size(a),1,k):end),1,b(sub2ind(size(b),max(1,1)):end),1);   dumvar2i=find((b(k))~=(dumvar2));dumvar5i=find((b(sub2ind(size(b),max(1,1)):end))~=(dumvar5));   b(k-1+dumvar2i)=dumvar2(dumvar2i); b(1-1+dumvar5i)=dumvar5(dumvar5i); 
[dumvar1,dumvar2,a(sub2ind(size(a),1,k-1):end),dumvar4,dumvar5]=caxpy(k-2,b(k-1),a(sub2ind(size(a),1,k-1):end),1,b(sub2ind(size(b),max(1,1)):end),1);   dumvar2i=find((b(k-1))~=(dumvar2));dumvar5i=find((b(sub2ind(size(b),max(1,1)):end))~=(dumvar5));   b(k-1-1+dumvar2i)=dumvar2(dumvar2i); b(1-1+dumvar5i)=dumvar5(dumvar5i); 
end;
%
%           APPLY D INVERSE.
%
ak = a(k,k)./conj(a(k-1,k));
akm1 = a(k-1,k-1)./a(k-1,k);
bk = b(k)./conj(a(k-1,k));
bkm1 = b(k-1)./a(k-1,k);
denom = ak.*akm1 - 1.0e0;
b(k) =(akm1.*bk-bkm1)./denom;
b(k-1) =(ak.*bkm1-bk)./denom;
k = fix(k - 2);
else;
%
%           1 X 1 PIVOT BLOCK.
%
if( k~=1 )
kp = fix(kpvt(k));
if( kp~=k )
%
%                 INTERCHANGE.
%
temp = b(k);
b(k) = b(kp);
b(kp) = temp;
end;
%
%              APPLY THE TRANSFORMATION.
%
[dumvar1,dumvar2,a(sub2ind(size(a),1,k):end),dumvar4,dumvar5]=caxpy(k-1,b(k),a(sub2ind(size(a),1,k):end),1,b(sub2ind(size(b),max(1,1)):end),1);   dumvar2i=find((b(k))~=(dumvar2));dumvar5i=find((b(sub2ind(size(b),max(1,1)):end))~=(dumvar5));   b(k-1+dumvar2i)=dumvar2(dumvar2i); b(1-1+dumvar5i)=dumvar5(dumvar5i); 
end;
%
%           APPLY D INVERSE.
%
b(k) = b(k)./a(k,k);
k = fix(k - 1);
end;
end;
%
%     LOOP FORWARD APPLYING THE TRANSFORMATIONS.
%
k = 1;
while( k<=n );
if( kpvt(k)<0 )
%
%           2 X 2 PIVOT BLOCK.
%
if( k~=1 )
%
%              APPLY THE TRANSFORMATION.
%
b(k) = b(k) + cdotc(k-1,a(sub2ind(size(a),1,k):end),1,b(sub2ind(size(b),max(1,1)):end),1);
b(k+1) = b(k+1) + cdotc(k-1,a(sub2ind(size(a),1,k+1):end),1,b(sub2ind(size(b),max(1,1)):end),1);
kp = fix(abs(kpvt(k)));
if( kp~=k )
%
%                 INTERCHANGE.
%
temp = b(k);
b(k) = b(kp);
b(kp) = temp;
end;
end;
k = fix(k + 2);
else;
%
%           1 X 1 PIVOT BLOCK.
%
if( k~=1 )
%
%              APPLY THE TRANSFORMATION.
%
b(k) = b(k) + cdotc(k-1,a(sub2ind(size(a),1,k):end),1,b(sub2ind(size(b),max(1,1)):end),1);
kp = fix(kpvt(k));
if( kp~=k )
%
%                 INTERCHANGE.
%
temp = b(k);
b(k) = b(kp);
b(kp) = temp;
end;
end;
k = fix(k + 1);
end;
end;
kpvt_shape=zeros(kpvt_shape);kpvt_shape(:)=kpvt(1:numel(kpvt_shape));kpvt=kpvt_shape;
a_shape=zeros(a_shape);a_shape(:)=a(1:numel(a_shape));a=a_shape;
b_shape=zeros(b_shape);b_shape(:)=b(1:numel(b_shape));b=b_shape;
end %subroutine chisl
%DECK CHKDER