root / src / lapack / double / dlascl.f @ 1
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| 1 | 1 | equemene | SUBROUTINE DLASCL( TYPE, KL, KU, CFROM, CTO, M, N, A, LDA, INFO ) |
|---|---|---|---|
| 2 | 1 | equemene | * |
| 3 | 1 | equemene | * -- LAPACK auxiliary routine (version 3.2) -- |
| 4 | 1 | equemene | * -- LAPACK is a software package provided by Univ. of Tennessee, -- |
| 5 | 1 | equemene | * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
| 6 | 1 | equemene | * November 2006 |
| 7 | 1 | equemene | * |
| 8 | 1 | equemene | * .. Scalar Arguments .. |
| 9 | 1 | equemene | CHARACTER TYPE |
| 10 | 1 | equemene | INTEGER INFO, KL, KU, LDA, M, N |
| 11 | 1 | equemene | DOUBLE PRECISION CFROM, CTO |
| 12 | 1 | equemene | * .. |
| 13 | 1 | equemene | * .. Array Arguments .. |
| 14 | 1 | equemene | DOUBLE PRECISION A( LDA, * ) |
| 15 | 1 | equemene | * .. |
| 16 | 1 | equemene | * |
| 17 | 1 | equemene | * Purpose |
| 18 | 1 | equemene | * ======= |
| 19 | 1 | equemene | * |
| 20 | 1 | equemene | * DLASCL multiplies the M by N real matrix A by the real scalar |
| 21 | 1 | equemene | * CTO/CFROM. This is done without over/underflow as long as the final |
| 22 | 1 | equemene | * result CTO*A(I,J)/CFROM does not over/underflow. TYPE specifies that |
| 23 | 1 | equemene | * A may be full, upper triangular, lower triangular, upper Hessenberg, |
| 24 | 1 | equemene | * or banded. |
| 25 | 1 | equemene | * |
| 26 | 1 | equemene | * Arguments |
| 27 | 1 | equemene | * ========= |
| 28 | 1 | equemene | * |
| 29 | 1 | equemene | * TYPE (input) CHARACTER*1 |
| 30 | 1 | equemene | * TYPE indices the storage type of the input matrix. |
| 31 | 1 | equemene | * = 'G': A is a full matrix. |
| 32 | 1 | equemene | * = 'L': A is a lower triangular matrix. |
| 33 | 1 | equemene | * = 'U': A is an upper triangular matrix. |
| 34 | 1 | equemene | * = 'H': A is an upper Hessenberg matrix. |
| 35 | 1 | equemene | * = 'B': A is a symmetric band matrix with lower bandwidth KL |
| 36 | 1 | equemene | * and upper bandwidth KU and with the only the lower |
| 37 | 1 | equemene | * half stored. |
| 38 | 1 | equemene | * = 'Q': A is a symmetric band matrix with lower bandwidth KL |
| 39 | 1 | equemene | * and upper bandwidth KU and with the only the upper |
| 40 | 1 | equemene | * half stored. |
| 41 | 1 | equemene | * = 'Z': A is a band matrix with lower bandwidth KL and upper |
| 42 | 1 | equemene | * bandwidth KU. |
| 43 | 1 | equemene | * |
| 44 | 1 | equemene | * KL (input) INTEGER |
| 45 | 1 | equemene | * The lower bandwidth of A. Referenced only if TYPE = 'B', |
| 46 | 1 | equemene | * 'Q' or 'Z'. |
| 47 | 1 | equemene | * |
| 48 | 1 | equemene | * KU (input) INTEGER |
| 49 | 1 | equemene | * The upper bandwidth of A. Referenced only if TYPE = 'B', |
| 50 | 1 | equemene | * 'Q' or 'Z'. |
| 51 | 1 | equemene | * |
| 52 | 1 | equemene | * CFROM (input) DOUBLE PRECISION |
| 53 | 1 | equemene | * CTO (input) DOUBLE PRECISION |
| 54 | 1 | equemene | * The matrix A is multiplied by CTO/CFROM. A(I,J) is computed |
| 55 | 1 | equemene | * without over/underflow if the final result CTO*A(I,J)/CFROM |
| 56 | 1 | equemene | * can be represented without over/underflow. CFROM must be |
| 57 | 1 | equemene | * nonzero. |
| 58 | 1 | equemene | * |
| 59 | 1 | equemene | * M (input) INTEGER |
| 60 | 1 | equemene | * The number of rows of the matrix A. M >= 0. |
| 61 | 1 | equemene | * |
| 62 | 1 | equemene | * N (input) INTEGER |
| 63 | 1 | equemene | * The number of columns of the matrix A. N >= 0. |
| 64 | 1 | equemene | * |
| 65 | 1 | equemene | * A (input/output) DOUBLE PRECISION array, dimension (LDA,N) |
| 66 | 1 | equemene | * The matrix to be multiplied by CTO/CFROM. See TYPE for the |
| 67 | 1 | equemene | * storage type. |
| 68 | 1 | equemene | * |
| 69 | 1 | equemene | * LDA (input) INTEGER |
| 70 | 1 | equemene | * The leading dimension of the array A. LDA >= max(1,M). |
| 71 | 1 | equemene | * |
| 72 | 1 | equemene | * INFO (output) INTEGER |
| 73 | 1 | equemene | * 0 - successful exit |
| 74 | 1 | equemene | * <0 - if INFO = -i, the i-th argument had an illegal value. |
| 75 | 1 | equemene | * |
| 76 | 1 | equemene | * ===================================================================== |
| 77 | 1 | equemene | * |
| 78 | 1 | equemene | * .. Parameters .. |
| 79 | 1 | equemene | DOUBLE PRECISION ZERO, ONE |
| 80 | 1 | equemene | PARAMETER ( ZERO = 0.0D0, ONE = 1.0D0 ) |
| 81 | 1 | equemene | * .. |
| 82 | 1 | equemene | * .. Local Scalars .. |
| 83 | 1 | equemene | LOGICAL DONE |
| 84 | 1 | equemene | INTEGER I, ITYPE, J, K1, K2, K3, K4 |
| 85 | 1 | equemene | DOUBLE PRECISION BIGNUM, CFROM1, CFROMC, CTO1, CTOC, MUL, SMLNUM |
| 86 | 1 | equemene | * .. |
| 87 | 1 | equemene | * .. External Functions .. |
| 88 | 1 | equemene | LOGICAL LSAME, DISNAN |
| 89 | 1 | equemene | DOUBLE PRECISION DLAMCH |
| 90 | 1 | equemene | EXTERNAL LSAME, DLAMCH, DISNAN |
| 91 | 1 | equemene | * .. |
| 92 | 1 | equemene | * .. Intrinsic Functions .. |
| 93 | 1 | equemene | INTRINSIC ABS, MAX, MIN |
| 94 | 1 | equemene | * .. |
| 95 | 1 | equemene | * .. External Subroutines .. |
| 96 | 1 | equemene | EXTERNAL XERBLA |
| 97 | 1 | equemene | * .. |
| 98 | 1 | equemene | * .. Executable Statements .. |
| 99 | 1 | equemene | * |
| 100 | 1 | equemene | * Test the input arguments |
| 101 | 1 | equemene | * |
| 102 | 1 | equemene | INFO = 0 |
| 103 | 1 | equemene | * |
| 104 | 1 | equemene | IF( LSAME( TYPE, 'G' ) ) THEN |
| 105 | 1 | equemene | ITYPE = 0 |
| 106 | 1 | equemene | ELSE IF( LSAME( TYPE, 'L' ) ) THEN |
| 107 | 1 | equemene | ITYPE = 1 |
| 108 | 1 | equemene | ELSE IF( LSAME( TYPE, 'U' ) ) THEN |
| 109 | 1 | equemene | ITYPE = 2 |
| 110 | 1 | equemene | ELSE IF( LSAME( TYPE, 'H' ) ) THEN |
| 111 | 1 | equemene | ITYPE = 3 |
| 112 | 1 | equemene | ELSE IF( LSAME( TYPE, 'B' ) ) THEN |
| 113 | 1 | equemene | ITYPE = 4 |
| 114 | 1 | equemene | ELSE IF( LSAME( TYPE, 'Q' ) ) THEN |
| 115 | 1 | equemene | ITYPE = 5 |
| 116 | 1 | equemene | ELSE IF( LSAME( TYPE, 'Z' ) ) THEN |
| 117 | 1 | equemene | ITYPE = 6 |
| 118 | 1 | equemene | ELSE |
| 119 | 1 | equemene | ITYPE = -1 |
| 120 | 1 | equemene | END IF |
| 121 | 1 | equemene | * |
| 122 | 1 | equemene | IF( ITYPE.EQ.-1 ) THEN |
| 123 | 1 | equemene | INFO = -1 |
| 124 | 1 | equemene | ELSE IF( CFROM.EQ.ZERO .OR. DISNAN(CFROM) ) THEN |
| 125 | 1 | equemene | INFO = -4 |
| 126 | 1 | equemene | ELSE IF( DISNAN(CTO) ) THEN |
| 127 | 1 | equemene | INFO = -5 |
| 128 | 1 | equemene | ELSE IF( M.LT.0 ) THEN |
| 129 | 1 | equemene | INFO = -6 |
| 130 | 1 | equemene | ELSE IF( N.LT.0 .OR. ( ITYPE.EQ.4 .AND. N.NE.M ) .OR. |
| 131 | 1 | equemene | $ ( ITYPE.EQ.5 .AND. N.NE.M ) ) THEN |
| 132 | 1 | equemene | INFO = -7 |
| 133 | 1 | equemene | ELSE IF( ITYPE.LE.3 .AND. LDA.LT.MAX( 1, M ) ) THEN |
| 134 | 1 | equemene | INFO = -9 |
| 135 | 1 | equemene | ELSE IF( ITYPE.GE.4 ) THEN |
| 136 | 1 | equemene | IF( KL.LT.0 .OR. KL.GT.MAX( M-1, 0 ) ) THEN |
| 137 | 1 | equemene | INFO = -2 |
| 138 | 1 | equemene | ELSE IF( KU.LT.0 .OR. KU.GT.MAX( N-1, 0 ) .OR. |
| 139 | 1 | equemene | $ ( ( ITYPE.EQ.4 .OR. ITYPE.EQ.5 ) .AND. KL.NE.KU ) ) |
| 140 | 1 | equemene | $ THEN |
| 141 | 1 | equemene | INFO = -3 |
| 142 | 1 | equemene | ELSE IF( ( ITYPE.EQ.4 .AND. LDA.LT.KL+1 ) .OR. |
| 143 | 1 | equemene | $ ( ITYPE.EQ.5 .AND. LDA.LT.KU+1 ) .OR. |
| 144 | 1 | equemene | $ ( ITYPE.EQ.6 .AND. LDA.LT.2*KL+KU+1 ) ) THEN |
| 145 | 1 | equemene | INFO = -9 |
| 146 | 1 | equemene | END IF |
| 147 | 1 | equemene | END IF |
| 148 | 1 | equemene | * |
| 149 | 1 | equemene | IF( INFO.NE.0 ) THEN |
| 150 | 1 | equemene | CALL XERBLA( 'DLASCL', -INFO ) |
| 151 | 1 | equemene | RETURN |
| 152 | 1 | equemene | END IF |
| 153 | 1 | equemene | * |
| 154 | 1 | equemene | * Quick return if possible |
| 155 | 1 | equemene | * |
| 156 | 1 | equemene | IF( N.EQ.0 .OR. M.EQ.0 ) |
| 157 | 1 | equemene | $ RETURN |
| 158 | 1 | equemene | * |
| 159 | 1 | equemene | * Get machine parameters |
| 160 | 1 | equemene | * |
| 161 | 1 | equemene | SMLNUM = DLAMCH( 'S' ) |
| 162 | 1 | equemene | BIGNUM = ONE / SMLNUM |
| 163 | 1 | equemene | * |
| 164 | 1 | equemene | CFROMC = CFROM |
| 165 | 1 | equemene | CTOC = CTO |
| 166 | 1 | equemene | * |
| 167 | 1 | equemene | 10 CONTINUE |
| 168 | 1 | equemene | CFROM1 = CFROMC*SMLNUM |
| 169 | 1 | equemene | IF( CFROM1.EQ.CFROMC ) THEN |
| 170 | 1 | equemene | ! CFROMC is an inf. Multiply by a correctly signed zero for |
| 171 | 1 | equemene | ! finite CTOC, or a NaN if CTOC is infinite. |
| 172 | 1 | equemene | MUL = CTOC / CFROMC |
| 173 | 1 | equemene | DONE = .TRUE. |
| 174 | 1 | equemene | CTO1 = CTOC |
| 175 | 1 | equemene | ELSE |
| 176 | 1 | equemene | CTO1 = CTOC / BIGNUM |
| 177 | 1 | equemene | IF( CTO1.EQ.CTOC ) THEN |
| 178 | 1 | equemene | ! CTOC is either 0 or an inf. In both cases, CTOC itself |
| 179 | 1 | equemene | ! serves as the correct multiplication factor. |
| 180 | 1 | equemene | MUL = CTOC |
| 181 | 1 | equemene | DONE = .TRUE. |
| 182 | 1 | equemene | CFROMC = ONE |
| 183 | 1 | equemene | ELSE IF( ABS( CFROM1 ).GT.ABS( CTOC ) .AND. CTOC.NE.ZERO ) THEN |
| 184 | 1 | equemene | MUL = SMLNUM |
| 185 | 1 | equemene | DONE = .FALSE. |
| 186 | 1 | equemene | CFROMC = CFROM1 |
| 187 | 1 | equemene | ELSE IF( ABS( CTO1 ).GT.ABS( CFROMC ) ) THEN |
| 188 | 1 | equemene | MUL = BIGNUM |
| 189 | 1 | equemene | DONE = .FALSE. |
| 190 | 1 | equemene | CTOC = CTO1 |
| 191 | 1 | equemene | ELSE |
| 192 | 1 | equemene | MUL = CTOC / CFROMC |
| 193 | 1 | equemene | DONE = .TRUE. |
| 194 | 1 | equemene | END IF |
| 195 | 1 | equemene | END IF |
| 196 | 1 | equemene | * |
| 197 | 1 | equemene | IF( ITYPE.EQ.0 ) THEN |
| 198 | 1 | equemene | * |
| 199 | 1 | equemene | * Full matrix |
| 200 | 1 | equemene | * |
| 201 | 1 | equemene | DO 30 J = 1, N |
| 202 | 1 | equemene | DO 20 I = 1, M |
| 203 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 204 | 1 | equemene | 20 CONTINUE |
| 205 | 1 | equemene | 30 CONTINUE |
| 206 | 1 | equemene | * |
| 207 | 1 | equemene | ELSE IF( ITYPE.EQ.1 ) THEN |
| 208 | 1 | equemene | * |
| 209 | 1 | equemene | * Lower triangular matrix |
| 210 | 1 | equemene | * |
| 211 | 1 | equemene | DO 50 J = 1, N |
| 212 | 1 | equemene | DO 40 I = J, M |
| 213 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 214 | 1 | equemene | 40 CONTINUE |
| 215 | 1 | equemene | 50 CONTINUE |
| 216 | 1 | equemene | * |
| 217 | 1 | equemene | ELSE IF( ITYPE.EQ.2 ) THEN |
| 218 | 1 | equemene | * |
| 219 | 1 | equemene | * Upper triangular matrix |
| 220 | 1 | equemene | * |
| 221 | 1 | equemene | DO 70 J = 1, N |
| 222 | 1 | equemene | DO 60 I = 1, MIN( J, M ) |
| 223 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 224 | 1 | equemene | 60 CONTINUE |
| 225 | 1 | equemene | 70 CONTINUE |
| 226 | 1 | equemene | * |
| 227 | 1 | equemene | ELSE IF( ITYPE.EQ.3 ) THEN |
| 228 | 1 | equemene | * |
| 229 | 1 | equemene | * Upper Hessenberg matrix |
| 230 | 1 | equemene | * |
| 231 | 1 | equemene | DO 90 J = 1, N |
| 232 | 1 | equemene | DO 80 I = 1, MIN( J+1, M ) |
| 233 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 234 | 1 | equemene | 80 CONTINUE |
| 235 | 1 | equemene | 90 CONTINUE |
| 236 | 1 | equemene | * |
| 237 | 1 | equemene | ELSE IF( ITYPE.EQ.4 ) THEN |
| 238 | 1 | equemene | * |
| 239 | 1 | equemene | * Lower half of a symmetric band matrix |
| 240 | 1 | equemene | * |
| 241 | 1 | equemene | K3 = KL + 1 |
| 242 | 1 | equemene | K4 = N + 1 |
| 243 | 1 | equemene | DO 110 J = 1, N |
| 244 | 1 | equemene | DO 100 I = 1, MIN( K3, K4-J ) |
| 245 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 246 | 1 | equemene | 100 CONTINUE |
| 247 | 1 | equemene | 110 CONTINUE |
| 248 | 1 | equemene | * |
| 249 | 1 | equemene | ELSE IF( ITYPE.EQ.5 ) THEN |
| 250 | 1 | equemene | * |
| 251 | 1 | equemene | * Upper half of a symmetric band matrix |
| 252 | 1 | equemene | * |
| 253 | 1 | equemene | K1 = KU + 2 |
| 254 | 1 | equemene | K3 = KU + 1 |
| 255 | 1 | equemene | DO 130 J = 1, N |
| 256 | 1 | equemene | DO 120 I = MAX( K1-J, 1 ), K3 |
| 257 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 258 | 1 | equemene | 120 CONTINUE |
| 259 | 1 | equemene | 130 CONTINUE |
| 260 | 1 | equemene | * |
| 261 | 1 | equemene | ELSE IF( ITYPE.EQ.6 ) THEN |
| 262 | 1 | equemene | * |
| 263 | 1 | equemene | * Band matrix |
| 264 | 1 | equemene | * |
| 265 | 1 | equemene | K1 = KL + KU + 2 |
| 266 | 1 | equemene | K2 = KL + 1 |
| 267 | 1 | equemene | K3 = 2*KL + KU + 1 |
| 268 | 1 | equemene | K4 = KL + KU + 1 + M |
| 269 | 1 | equemene | DO 150 J = 1, N |
| 270 | 1 | equemene | DO 140 I = MAX( K1-J, K2 ), MIN( K3, K4-J ) |
| 271 | 1 | equemene | A( I, J ) = A( I, J )*MUL |
| 272 | 1 | equemene | 140 CONTINUE |
| 273 | 1 | equemene | 150 CONTINUE |
| 274 | 1 | equemene | * |
| 275 | 1 | equemene | END IF |
| 276 | 1 | equemene | * |
| 277 | 1 | equemene | IF( .NOT.DONE ) |
| 278 | 1 | equemene | $ GO TO 10 |
| 279 | 1 | equemene | * |
| 280 | 1 | equemene | RETURN |
| 281 | 1 | equemene | * |
| 282 | 1 | equemene | * End of DLASCL |
| 283 | 1 | equemene | * |
| 284 | 1 | equemene | END |