5 * Revision 1.1.1.1 1996/02/15 17:48:49 mclareni
9 #include "kernnum/pilot.h"
10 SUBROUTINE DINV(N,A,IDIM,R,IFAIL)
12 DOUBLE PRECISION A(IDIM,N),DET,TEMP,S,
13 $ C11,C12,C13,C21,C22,C23,C31,C32,C33
15 DATA NAME/'DINV'/,KPRNT/0/
17 C ******************************************************************
19 C REPLACES A BY ITS INVERSE.
21 C (PARAMETERS AS FOR DEQINV.)
23 C CALLS ... DFACT, DFINV, F010PR, ABEND.
25 C ******************************************************************
27 C TEST FOR PARAMETER ERRORS.
29 IF((N.LT.1).OR.(N.GT.IDIM)) GO TO 7
40 C11=A(2,2)*A(3,3)-A(2,3)*A(3,2)
41 C12=A(2,3)*A(3,1)-A(2,1)*A(3,3)
42 C13=A(2,1)*A(3,2)-A(2,2)*A(3,1)
43 C21=A(3,2)*A(1,3)-A(3,3)*A(1,2)
44 C22=A(3,3)*A(1,1)-A(3,1)*A(1,3)
45 C23=A(3,1)*A(1,2)-A(3,2)*A(1,1)
46 C31=A(1,2)*A(2,3)-A(1,3)*A(2,2)
47 C32=A(1,3)*A(2,1)-A(1,1)*A(2,3)
48 C33=A(1,1)*A(2,2)-A(1,2)*A(2,1)
53 C (SET TEMP=PIVOT AND DET=PIVOT*DET.)
60 1 IF(T3.GE.T1) GO TO 2
69 C SET ELEMENTS OF INVERSE IN A.
70 3 IF(DET.EQ.0D0) GO TO 8
85 C N=2 CASE BY CRAMERS RULE.
87 DET=A(1,1)*A(2,2)-A(1,2)*A(2,1)
88 IF(DET.EQ.0D0) GO TO 8
99 5 IF(A(1,1).EQ.0D0) GO TO 8
103 C N.GT.3 CASES. FACTORIZE MATRIX AND INVERT.
105 6 CALL DFACT(N,A,IDIM,R,IFAIL,DET,JFAIL)
106 IF(IFAIL.NE.0) RETURN
107 CALL DFINV(N,A,IDIM,R)
113 CALL F010PR(NAME,N,IDIM,K,KPRNT)