1 SUBROUTINE DSYSWAPR( UPLO, N, A, LDA, I1, I2)
2 *
3 * -- LAPACK auxiliary routine (version 3.3.1) --
4 * -- LAPACK is a software package provided by Univ. of Tennessee, --
5 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
6 * -- April 2011 --
7 *
8 * .. Scalar Arguments ..
9 CHARACTER UPLO
10 INTEGER I1, I2, LDA, N
11 * ..
12 * .. Array Arguments ..
13 DOUBLE PRECISION A( LDA, N )
14 *
15 * Purpose
16 * =======
17 *
18 * DSYSWAPR applies an elementary permutation on the rows and the columns of
19 * a symmetric matrix.
20 *
21 * Arguments
22 * =========
23 *
24 * UPLO (input) CHARACTER*1
25 * Specifies whether the details of the factorization are stored
26 * as an upper or lower triangular matrix.
27 * = 'U': Upper triangular, form is A = U*D*U**T;
28 * = 'L': Lower triangular, form is A = L*D*L**T.
29 *
30 * N (input) INTEGER
31 * The order of the matrix A. N >= 0.
32 *
33 * A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
34 * On entry, the NB diagonal matrix D and the multipliers
35 * used to obtain the factor U or L as computed by DSYTRF.
36 *
37 * On exit, if INFO = 0, the (symmetric) inverse of the original
38 * matrix. If UPLO = 'U', the upper triangular part of the
39 * inverse is formed and the part of A below the diagonal is not
40 * referenced; if UPLO = 'L' the lower triangular part of the
41 * inverse is formed and the part of A above the diagonal is
42 * not referenced.
43 *
44 * LDA (input) INTEGER
45 * The leading dimension of the array A. LDA >= max(1,N).
46 *
47 * I1 (input) INTEGER
48 * Index of the first row to swap
49 *
50 * I2 (input) INTEGER
51 * Index of the second row to swap
52 *
53 * =====================================================================
54 *
55 * ..
56 * .. Local Scalars ..
57 LOGICAL UPPER
58 INTEGER I
59 DOUBLE PRECISION TMP
60 *
61 * .. External Functions ..
62 LOGICAL LSAME
63 EXTERNAL LSAME
64 * ..
65 * .. External Subroutines ..
66 EXTERNAL DSWAP
67 * ..
68 * .. Executable Statements ..
69 *
70 UPPER = LSAME( UPLO, 'U' )
71 IF (UPPER) THEN
72 *
73 * UPPER
74 * first swap
75 * - swap column I1 and I2 from I1 to I1-1
76 CALL DSWAP( I1-1, A(1,I1), 1, A(1,I2), 1 )
77 *
78 * second swap :
79 * - swap A(I1,I1) and A(I2,I2)
80 * - swap row I1 from I1+1 to I2-1 with col I2 from I1+1 to I2-1
81 TMP=A(I1,I1)
82 A(I1,I1)=A(I2,I2)
83 A(I2,I2)=TMP
84 *
85 DO I=1,I2-I1-1
86 TMP=A(I1,I1+I)
87 A(I1,I1+I)=A(I1+I,I2)
88 A(I1+I,I2)=TMP
89 END DO
90 *
91 * third swap
92 * - swap row I1 and I2 from I2+1 to N
93 DO I=I2+1,N
94 TMP=A(I1,I)
95 A(I1,I)=A(I2,I)
96 A(I2,I)=TMP
97 END DO
98 *
99 ELSE
100 *
101 * LOWER
102 * first swap
103 * - swap row I1 and I2 from I1 to I1-1
104 CALL DSWAP( I1-1, A(I1,1), LDA, A(I2,1), LDA )
105 *
106 * second swap :
107 * - swap A(I1,I1) and A(I2,I2)
108 * - swap col I1 from I1+1 to I2-1 with row I2 from I1+1 to I2-1
109 TMP=A(I1,I1)
110 A(I1,I1)=A(I2,I2)
111 A(I2,I2)=TMP
112 *
113 DO I=1,I2-I1-1
114 TMP=A(I1+I,I1)
115 A(I1+I,I1)=A(I2,I1+I)
116 A(I2,I1+I)=TMP
117 END DO
118 *
119 * third swap
120 * - swap col I1 and I2 from I2+1 to N
121 DO I=I2+1,N
122 TMP=A(I,I1)
123 A(I,I1)=A(I,I2)
124 A(I,I2)=TMP
125 END DO
126 *
127 ENDIF
128 END SUBROUTINE DSYSWAPR
129
2 *
3 * -- LAPACK auxiliary routine (version 3.3.1) --
4 * -- LAPACK is a software package provided by Univ. of Tennessee, --
5 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
6 * -- April 2011 --
7 *
8 * .. Scalar Arguments ..
9 CHARACTER UPLO
10 INTEGER I1, I2, LDA, N
11 * ..
12 * .. Array Arguments ..
13 DOUBLE PRECISION A( LDA, N )
14 *
15 * Purpose
16 * =======
17 *
18 * DSYSWAPR applies an elementary permutation on the rows and the columns of
19 * a symmetric matrix.
20 *
21 * Arguments
22 * =========
23 *
24 * UPLO (input) CHARACTER*1
25 * Specifies whether the details of the factorization are stored
26 * as an upper or lower triangular matrix.
27 * = 'U': Upper triangular, form is A = U*D*U**T;
28 * = 'L': Lower triangular, form is A = L*D*L**T.
29 *
30 * N (input) INTEGER
31 * The order of the matrix A. N >= 0.
32 *
33 * A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
34 * On entry, the NB diagonal matrix D and the multipliers
35 * used to obtain the factor U or L as computed by DSYTRF.
36 *
37 * On exit, if INFO = 0, the (symmetric) inverse of the original
38 * matrix. If UPLO = 'U', the upper triangular part of the
39 * inverse is formed and the part of A below the diagonal is not
40 * referenced; if UPLO = 'L' the lower triangular part of the
41 * inverse is formed and the part of A above the diagonal is
42 * not referenced.
43 *
44 * LDA (input) INTEGER
45 * The leading dimension of the array A. LDA >= max(1,N).
46 *
47 * I1 (input) INTEGER
48 * Index of the first row to swap
49 *
50 * I2 (input) INTEGER
51 * Index of the second row to swap
52 *
53 * =====================================================================
54 *
55 * ..
56 * .. Local Scalars ..
57 LOGICAL UPPER
58 INTEGER I
59 DOUBLE PRECISION TMP
60 *
61 * .. External Functions ..
62 LOGICAL LSAME
63 EXTERNAL LSAME
64 * ..
65 * .. External Subroutines ..
66 EXTERNAL DSWAP
67 * ..
68 * .. Executable Statements ..
69 *
70 UPPER = LSAME( UPLO, 'U' )
71 IF (UPPER) THEN
72 *
73 * UPPER
74 * first swap
75 * - swap column I1 and I2 from I1 to I1-1
76 CALL DSWAP( I1-1, A(1,I1), 1, A(1,I2), 1 )
77 *
78 * second swap :
79 * - swap A(I1,I1) and A(I2,I2)
80 * - swap row I1 from I1+1 to I2-1 with col I2 from I1+1 to I2-1
81 TMP=A(I1,I1)
82 A(I1,I1)=A(I2,I2)
83 A(I2,I2)=TMP
84 *
85 DO I=1,I2-I1-1
86 TMP=A(I1,I1+I)
87 A(I1,I1+I)=A(I1+I,I2)
88 A(I1+I,I2)=TMP
89 END DO
90 *
91 * third swap
92 * - swap row I1 and I2 from I2+1 to N
93 DO I=I2+1,N
94 TMP=A(I1,I)
95 A(I1,I)=A(I2,I)
96 A(I2,I)=TMP
97 END DO
98 *
99 ELSE
100 *
101 * LOWER
102 * first swap
103 * - swap row I1 and I2 from I1 to I1-1
104 CALL DSWAP( I1-1, A(I1,1), LDA, A(I2,1), LDA )
105 *
106 * second swap :
107 * - swap A(I1,I1) and A(I2,I2)
108 * - swap col I1 from I1+1 to I2-1 with row I2 from I1+1 to I2-1
109 TMP=A(I1,I1)
110 A(I1,I1)=A(I2,I2)
111 A(I2,I2)=TMP
112 *
113 DO I=1,I2-I1-1
114 TMP=A(I1+I,I1)
115 A(I1+I,I1)=A(I2,I1+I)
116 A(I2,I1+I)=TMP
117 END DO
118 *
119 * third swap
120 * - swap col I1 and I2 from I2+1 to N
121 DO I=I2+1,N
122 TMP=A(I,I1)
123 A(I,I1)=A(I,I2)
124 A(I,I2)=TMP
125 END DO
126 *
127 ENDIF
128 END SUBROUTINE DSYSWAPR
129