root / src / minv.f90 @ 7
Historique | Voir | Annoter | Télécharger (3,03 ko)
| 1 | 1 | equemene | SUBROUTINE MINV(A,N,D) |
|---|---|---|---|
| 2 | 1 | equemene | |
| 3 | 1 | equemene | IMPLICIT NONE |
| 4 | 1 | equemene | integer, parameter :: KINT = kind(1) |
| 5 | 1 | equemene | integer, parameter :: KREAL = kind(1.0d0) |
| 6 | 1 | equemene | |
| 7 | 1 | equemene | REAL(KREAL), INTENT(INOUT) :: A(N*N) |
| 8 | 1 | equemene | INTEGER(KINT), INTENT(IN) :: N |
| 9 | 1 | equemene | REAL(KREAL), INTENT(OUT) :: D |
| 10 | 1 | equemene | |
| 11 | 1 | equemene | |
| 12 | 1 | equemene | !********************************************************************** |
| 13 | 1 | equemene | !* |
| 14 | 1 | equemene | !* INVERT A MATRIX USING GAUSS-JORDAN METHOD. PART OF DIIS |
| 15 | 1 | equemene | !* A - INPUT MATRIX (MUST BE A GENERAL MATRIX), DESTROYED IN |
| 16 | 1 | equemene | !* COMPUTATION AND REPLACED BY RESULTANT INVERSE. |
| 17 | 1 | equemene | !* N - ORDER OF MATRIX A |
| 18 | 1 | equemene | !* D - RESULTANT DETERMINANT |
| 19 | 1 | equemene | !* |
| 20 | 1 | equemene | !********************************************************************** |
| 21 | 1 | equemene | INTEGER(KINT), ALLOCATABLE :: L(:), M(:) |
| 22 | 1 | equemene | INTEGER(KINT) :: I,J,K,NK,KK,KI,KJ,IZ,IJ,JP,JK,IK,JR,JQ,JI |
| 23 | 1 | equemene | |
| 24 | 1 | equemene | REAL(KREAL) :: BigA,Hold |
| 25 | 1 | equemene | |
| 26 | 1 | equemene | ALLOCATE(L(N),M(N)) |
| 27 | 1 | equemene | ! |
| 28 | 1 | equemene | ! SEARCH FOR LARGEST ELEMENT |
| 29 | 1 | equemene | ! |
| 30 | 1 | equemene | D=1.0D0 |
| 31 | 1 | equemene | NK=-N |
| 32 | 1 | equemene | DO 180 K=1,N |
| 33 | 1 | equemene | NK=NK+N |
| 34 | 1 | equemene | L(K)=K |
| 35 | 1 | equemene | M(K)=K |
| 36 | 1 | equemene | KK=NK+K |
| 37 | 1 | equemene | BIGA=A(KK) |
| 38 | 1 | equemene | DO 20 J=K,N |
| 39 | 1 | equemene | IZ=N*(J-1) |
| 40 | 1 | equemene | DO 20 I=K,N |
| 41 | 1 | equemene | IJ=IZ+I |
| 42 | 1 | equemene | 10 IF (ABS(BIGA).LT.ABS(A(IJ)))THEN |
| 43 | 1 | equemene | BIGA=A(IJ) |
| 44 | 1 | equemene | L(K)=I |
| 45 | 1 | equemene | M(K)=J |
| 46 | 1 | equemene | ENDIF |
| 47 | 1 | equemene | 20 CONTINUE |
| 48 | 1 | equemene | ! |
| 49 | 1 | equemene | ! INTERCHANGE ROWS |
| 50 | 1 | equemene | ! |
| 51 | 1 | equemene | J=L(K) |
| 52 | 1 | equemene | IF (J-K) 50,50,30 |
| 53 | 1 | equemene | 30 KI=K-N |
| 54 | 1 | equemene | DO 40 I=1,N |
| 55 | 1 | equemene | KI=KI+N |
| 56 | 1 | equemene | HOLD=-A(KI) |
| 57 | 1 | equemene | JI=KI-K+J |
| 58 | 1 | equemene | A(KI)=A(JI) |
| 59 | 1 | equemene | 40 A(JI)=HOLD |
| 60 | 1 | equemene | ! |
| 61 | 1 | equemene | ! INTERCHANGE COLUMNS |
| 62 | 1 | equemene | ! |
| 63 | 1 | equemene | 50 I=M(K) |
| 64 | 1 | equemene | IF (I-K) 80,80,60 |
| 65 | 1 | equemene | 60 JP=N*(I-1) |
| 66 | 1 | equemene | DO 70 J=1,N |
| 67 | 1 | equemene | JK=NK+J |
| 68 | 1 | equemene | JI=JP+J |
| 69 | 1 | equemene | HOLD=-A(JK) |
| 70 | 1 | equemene | A(JK)=A(JI) |
| 71 | 1 | equemene | 70 A(JI)=HOLD |
| 72 | 1 | equemene | !C |
| 73 | 1 | equemene | !C DIVIDE COLUMN BY MINUS PIVOT (VALUE OF PIVOT ELEMENT IS |
| 74 | 1 | equemene | !C CONTAINED IN BIGA) |
| 75 | 1 | equemene | !C |
| 76 | 1 | equemene | 80 IF (BIGA) 100,90,100 |
| 77 | 1 | equemene | 90 D=0.0 |
| 78 | 1 | equemene | RETURN |
| 79 | 1 | equemene | 100 DO 120 I=1,N |
| 80 | 1 | equemene | IF (I-K) 110,120,110 |
| 81 | 1 | equemene | 110 IK=NK+I |
| 82 | 1 | equemene | A(IK)=A(IK)/(-BIGA) |
| 83 | 1 | equemene | 120 CONTINUE |
| 84 | 1 | equemene | !C REDUCE MATRIX |
| 85 | 1 | equemene | DO 150 I=1,N |
| 86 | 1 | equemene | IK=NK+I |
| 87 | 1 | equemene | HOLD=A(IK) |
| 88 | 1 | equemene | IJ=I-N |
| 89 | 1 | equemene | DO 150 J=1,N |
| 90 | 1 | equemene | IJ=IJ+N |
| 91 | 1 | equemene | IF (I-K) 130,150,130 |
| 92 | 1 | equemene | 130 IF (J-K) 140,150,140 |
| 93 | 1 | equemene | 140 KJ=IJ-I+K |
| 94 | 1 | equemene | A(IJ)=HOLD*A(KJ)+A(IJ) |
| 95 | 1 | equemene | 150 CONTINUE |
| 96 | 1 | equemene | !C |
| 97 | 1 | equemene | !C DIVIDE ROW BY PIVOT |
| 98 | 1 | equemene | !C |
| 99 | 1 | equemene | KJ=K-N |
| 100 | 1 | equemene | DO 170 J=1,N |
| 101 | 1 | equemene | KJ=KJ+N |
| 102 | 1 | equemene | IF (J-K) 160,170,160 |
| 103 | 1 | equemene | 160 A(KJ)=A(KJ)/BIGA |
| 104 | 1 | equemene | 170 CONTINUE |
| 105 | 1 | equemene | !C |
| 106 | 1 | equemene | !C PRODUCT OF PIVOTS |
| 107 | 1 | equemene | !C |
| 108 | 1 | equemene | D=MAX(-1.D25,MIN(1.D25,D)) |
| 109 | 1 | equemene | D=D*BIGA |
| 110 | 1 | equemene | !C |
| 111 | 1 | equemene | !C REPLACE PIVOT BY RECIPROCAL |
| 112 | 1 | equemene | !C |
| 113 | 1 | equemene | A(KK)=1.0/BIGA |
| 114 | 1 | equemene | 180 CONTINUE |
| 115 | 1 | equemene | !C |
| 116 | 1 | equemene | !C FINAL ROW AND COLUMN INTERCHANGE |
| 117 | 1 | equemene | !C |
| 118 | 1 | equemene | K=N |
| 119 | 1 | equemene | 190 K=(K-1) |
| 120 | 1 | equemene | IF (K) 260,260,200 |
| 121 | 1 | equemene | 200 I=L(K) |
| 122 | 1 | equemene | IF (I-K) 230,230,210 |
| 123 | 1 | equemene | 210 JQ=N*(K-1) |
| 124 | 1 | equemene | JR=N*(I-1) |
| 125 | 1 | equemene | DO 220 J=1,N |
| 126 | 1 | equemene | JK=JQ+J |
| 127 | 1 | equemene | HOLD=A(JK) |
| 128 | 1 | equemene | JI=JR+J |
| 129 | 1 | equemene | A(JK)=-A(JI) |
| 130 | 1 | equemene | 220 A(JI)=HOLD |
| 131 | 1 | equemene | 230 J=M(K) |
| 132 | 1 | equemene | IF (J-K) 190,190,240 |
| 133 | 1 | equemene | 240 KI=K-N |
| 134 | 1 | equemene | DO 250 I=1,N |
| 135 | 1 | equemene | KI=KI+N |
| 136 | 1 | equemene | HOLD=A(KI) |
| 137 | 1 | equemene | JI=KI-K+J |
| 138 | 1 | equemene | A(KI)=-A(JI) |
| 139 | 1 | equemene | 250 A(JI) =HOLD |
| 140 | 1 | equemene | GO TO 190 |
| 141 | 1 | equemene | 260 RETURN |
| 142 | 1 | equemene | END |