root / src / lapack / double / dlarfb.f @ 1
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1 | 1 | equemene | SUBROUTINE DLARFB( SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, |
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2 | 1 | equemene | $ T, LDT, C, LDC, WORK, LDWORK ) |
3 | 1 | equemene | IMPLICIT NONE |
4 | 1 | equemene | * |
5 | 1 | equemene | * -- LAPACK auxiliary routine (version 3.2) -- |
6 | 1 | equemene | * -- LAPACK is a software package provided by Univ. of Tennessee, -- |
7 | 1 | equemene | * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
8 | 1 | equemene | * November 2006 |
9 | 1 | equemene | * |
10 | 1 | equemene | * .. Scalar Arguments .. |
11 | 1 | equemene | CHARACTER DIRECT, SIDE, STOREV, TRANS |
12 | 1 | equemene | INTEGER K, LDC, LDT, LDV, LDWORK, M, N |
13 | 1 | equemene | * .. |
14 | 1 | equemene | * .. Array Arguments .. |
15 | 1 | equemene | DOUBLE PRECISION C( LDC, * ), T( LDT, * ), V( LDV, * ), |
16 | 1 | equemene | $ WORK( LDWORK, * ) |
17 | 1 | equemene | * .. |
18 | 1 | equemene | * |
19 | 1 | equemene | * Purpose |
20 | 1 | equemene | * ======= |
21 | 1 | equemene | * |
22 | 1 | equemene | * DLARFB applies a real block reflector H or its transpose H' to a |
23 | 1 | equemene | * real m by n matrix C, from either the left or the right. |
24 | 1 | equemene | * |
25 | 1 | equemene | * Arguments |
26 | 1 | equemene | * ========= |
27 | 1 | equemene | * |
28 | 1 | equemene | * SIDE (input) CHARACTER*1 |
29 | 1 | equemene | * = 'L': apply H or H' from the Left |
30 | 1 | equemene | * = 'R': apply H or H' from the Right |
31 | 1 | equemene | * |
32 | 1 | equemene | * TRANS (input) CHARACTER*1 |
33 | 1 | equemene | * = 'N': apply H (No transpose) |
34 | 1 | equemene | * = 'T': apply H' (Transpose) |
35 | 1 | equemene | * |
36 | 1 | equemene | * DIRECT (input) CHARACTER*1 |
37 | 1 | equemene | * Indicates how H is formed from a product of elementary |
38 | 1 | equemene | * reflectors |
39 | 1 | equemene | * = 'F': H = H(1) H(2) . . . H(k) (Forward) |
40 | 1 | equemene | * = 'B': H = H(k) . . . H(2) H(1) (Backward) |
41 | 1 | equemene | * |
42 | 1 | equemene | * STOREV (input) CHARACTER*1 |
43 | 1 | equemene | * Indicates how the vectors which define the elementary |
44 | 1 | equemene | * reflectors are stored: |
45 | 1 | equemene | * = 'C': Columnwise |
46 | 1 | equemene | * = 'R': Rowwise |
47 | 1 | equemene | * |
48 | 1 | equemene | * M (input) INTEGER |
49 | 1 | equemene | * The number of rows of the matrix C. |
50 | 1 | equemene | * |
51 | 1 | equemene | * N (input) INTEGER |
52 | 1 | equemene | * The number of columns of the matrix C. |
53 | 1 | equemene | * |
54 | 1 | equemene | * K (input) INTEGER |
55 | 1 | equemene | * The order of the matrix T (= the number of elementary |
56 | 1 | equemene | * reflectors whose product defines the block reflector). |
57 | 1 | equemene | * |
58 | 1 | equemene | * V (input) DOUBLE PRECISION array, dimension |
59 | 1 | equemene | * (LDV,K) if STOREV = 'C' |
60 | 1 | equemene | * (LDV,M) if STOREV = 'R' and SIDE = 'L' |
61 | 1 | equemene | * (LDV,N) if STOREV = 'R' and SIDE = 'R' |
62 | 1 | equemene | * The matrix V. See further details. |
63 | 1 | equemene | * |
64 | 1 | equemene | * LDV (input) INTEGER |
65 | 1 | equemene | * The leading dimension of the array V. |
66 | 1 | equemene | * If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M); |
67 | 1 | equemene | * if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N); |
68 | 1 | equemene | * if STOREV = 'R', LDV >= K. |
69 | 1 | equemene | * |
70 | 1 | equemene | * T (input) DOUBLE PRECISION array, dimension (LDT,K) |
71 | 1 | equemene | * The triangular k by k matrix T in the representation of the |
72 | 1 | equemene | * block reflector. |
73 | 1 | equemene | * |
74 | 1 | equemene | * LDT (input) INTEGER |
75 | 1 | equemene | * The leading dimension of the array T. LDT >= K. |
76 | 1 | equemene | * |
77 | 1 | equemene | * C (input/output) DOUBLE PRECISION array, dimension (LDC,N) |
78 | 1 | equemene | * On entry, the m by n matrix C. |
79 | 1 | equemene | * On exit, C is overwritten by H*C or H'*C or C*H or C*H'. |
80 | 1 | equemene | * |
81 | 1 | equemene | * LDC (input) INTEGER |
82 | 1 | equemene | * The leading dimension of the array C. LDA >= max(1,M). |
83 | 1 | equemene | * |
84 | 1 | equemene | * WORK (workspace) DOUBLE PRECISION array, dimension (LDWORK,K) |
85 | 1 | equemene | * |
86 | 1 | equemene | * LDWORK (input) INTEGER |
87 | 1 | equemene | * The leading dimension of the array WORK. |
88 | 1 | equemene | * If SIDE = 'L', LDWORK >= max(1,N); |
89 | 1 | equemene | * if SIDE = 'R', LDWORK >= max(1,M). |
90 | 1 | equemene | * |
91 | 1 | equemene | * ===================================================================== |
92 | 1 | equemene | * |
93 | 1 | equemene | * .. Parameters .. |
94 | 1 | equemene | DOUBLE PRECISION ONE |
95 | 1 | equemene | PARAMETER ( ONE = 1.0D+0 ) |
96 | 1 | equemene | * .. |
97 | 1 | equemene | * .. Local Scalars .. |
98 | 1 | equemene | CHARACTER TRANST |
99 | 1 | equemene | INTEGER I, J, LASTV, LASTC |
100 | 1 | equemene | * .. |
101 | 1 | equemene | * .. External Functions .. |
102 | 1 | equemene | LOGICAL LSAME |
103 | 1 | equemene | INTEGER ILADLR, ILADLC |
104 | 1 | equemene | EXTERNAL LSAME, ILADLR, ILADLC |
105 | 1 | equemene | * .. |
106 | 1 | equemene | * .. External Subroutines .. |
107 | 1 | equemene | EXTERNAL DCOPY, DGEMM, DTRMM |
108 | 1 | equemene | * .. |
109 | 1 | equemene | * .. Executable Statements .. |
110 | 1 | equemene | * |
111 | 1 | equemene | * Quick return if possible |
112 | 1 | equemene | * |
113 | 1 | equemene | IF( M.LE.0 .OR. N.LE.0 ) |
114 | 1 | equemene | $ RETURN |
115 | 1 | equemene | * |
116 | 1 | equemene | IF( LSAME( TRANS, 'N' ) ) THEN |
117 | 1 | equemene | TRANST = 'T' |
118 | 1 | equemene | ELSE |
119 | 1 | equemene | TRANST = 'N' |
120 | 1 | equemene | END IF |
121 | 1 | equemene | * |
122 | 1 | equemene | IF( LSAME( STOREV, 'C' ) ) THEN |
123 | 1 | equemene | * |
124 | 1 | equemene | IF( LSAME( DIRECT, 'F' ) ) THEN |
125 | 1 | equemene | * |
126 | 1 | equemene | * Let V = ( V1 ) (first K rows) |
127 | 1 | equemene | * ( V2 ) |
128 | 1 | equemene | * where V1 is unit lower triangular. |
129 | 1 | equemene | * |
130 | 1 | equemene | IF( LSAME( SIDE, 'L' ) ) THEN |
131 | 1 | equemene | * |
132 | 1 | equemene | * Form H * C or H' * C where C = ( C1 ) |
133 | 1 | equemene | * ( C2 ) |
134 | 1 | equemene | * |
135 | 1 | equemene | LASTV = MAX( K, ILADLR( M, K, V, LDV ) ) |
136 | 1 | equemene | LASTC = ILADLC( LASTV, N, C, LDC ) |
137 | 1 | equemene | * |
138 | 1 | equemene | * W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) |
139 | 1 | equemene | * |
140 | 1 | equemene | * W := C1' |
141 | 1 | equemene | * |
142 | 1 | equemene | DO 10 J = 1, K |
143 | 1 | equemene | CALL DCOPY( LASTC, C( J, 1 ), LDC, WORK( 1, J ), 1 ) |
144 | 1 | equemene | 10 CONTINUE |
145 | 1 | equemene | * |
146 | 1 | equemene | * W := W * V1 |
147 | 1 | equemene | * |
148 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'No transpose', 'Unit', |
149 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
150 | 1 | equemene | IF( LASTV.GT.K ) THEN |
151 | 1 | equemene | * |
152 | 1 | equemene | * W := W + C2'*V2 |
153 | 1 | equemene | * |
154 | 1 | equemene | CALL DGEMM( 'Transpose', 'No transpose', |
155 | 1 | equemene | $ LASTC, K, LASTV-K, |
156 | 1 | equemene | $ ONE, C( K+1, 1 ), LDC, V( K+1, 1 ), LDV, |
157 | 1 | equemene | $ ONE, WORK, LDWORK ) |
158 | 1 | equemene | END IF |
159 | 1 | equemene | * |
160 | 1 | equemene | * W := W * T' or W * T |
161 | 1 | equemene | * |
162 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', TRANST, 'Non-unit', |
163 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
164 | 1 | equemene | * |
165 | 1 | equemene | * C := C - V * W' |
166 | 1 | equemene | * |
167 | 1 | equemene | IF( LASTV.GT.K ) THEN |
168 | 1 | equemene | * |
169 | 1 | equemene | * C2 := C2 - V2 * W' |
170 | 1 | equemene | * |
171 | 1 | equemene | CALL DGEMM( 'No transpose', 'Transpose', |
172 | 1 | equemene | $ LASTV-K, LASTC, K, |
173 | 1 | equemene | $ -ONE, V( K+1, 1 ), LDV, WORK, LDWORK, ONE, |
174 | 1 | equemene | $ C( K+1, 1 ), LDC ) |
175 | 1 | equemene | END IF |
176 | 1 | equemene | * |
177 | 1 | equemene | * W := W * V1' |
178 | 1 | equemene | * |
179 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'Transpose', 'Unit', |
180 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
181 | 1 | equemene | * |
182 | 1 | equemene | * C1 := C1 - W' |
183 | 1 | equemene | * |
184 | 1 | equemene | DO 30 J = 1, K |
185 | 1 | equemene | DO 20 I = 1, LASTC |
186 | 1 | equemene | C( J, I ) = C( J, I ) - WORK( I, J ) |
187 | 1 | equemene | 20 CONTINUE |
188 | 1 | equemene | 30 CONTINUE |
189 | 1 | equemene | * |
190 | 1 | equemene | ELSE IF( LSAME( SIDE, 'R' ) ) THEN |
191 | 1 | equemene | * |
192 | 1 | equemene | * Form C * H or C * H' where C = ( C1 C2 ) |
193 | 1 | equemene | * |
194 | 1 | equemene | LASTV = MAX( K, ILADLR( N, K, V, LDV ) ) |
195 | 1 | equemene | LASTC = ILADLR( M, LASTV, C, LDC ) |
196 | 1 | equemene | * |
197 | 1 | equemene | * W := C * V = (C1*V1 + C2*V2) (stored in WORK) |
198 | 1 | equemene | * |
199 | 1 | equemene | * W := C1 |
200 | 1 | equemene | * |
201 | 1 | equemene | DO 40 J = 1, K |
202 | 1 | equemene | CALL DCOPY( LASTC, C( 1, J ), 1, WORK( 1, J ), 1 ) |
203 | 1 | equemene | 40 CONTINUE |
204 | 1 | equemene | * |
205 | 1 | equemene | * W := W * V1 |
206 | 1 | equemene | * |
207 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'No transpose', 'Unit', |
208 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
209 | 1 | equemene | IF( LASTV.GT.K ) THEN |
210 | 1 | equemene | * |
211 | 1 | equemene | * W := W + C2 * V2 |
212 | 1 | equemene | * |
213 | 1 | equemene | CALL DGEMM( 'No transpose', 'No transpose', |
214 | 1 | equemene | $ LASTC, K, LASTV-K, |
215 | 1 | equemene | $ ONE, C( 1, K+1 ), LDC, V( K+1, 1 ), LDV, |
216 | 1 | equemene | $ ONE, WORK, LDWORK ) |
217 | 1 | equemene | END IF |
218 | 1 | equemene | * |
219 | 1 | equemene | * W := W * T or W * T' |
220 | 1 | equemene | * |
221 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', TRANS, 'Non-unit', |
222 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
223 | 1 | equemene | * |
224 | 1 | equemene | * C := C - W * V' |
225 | 1 | equemene | * |
226 | 1 | equemene | IF( LASTV.GT.K ) THEN |
227 | 1 | equemene | * |
228 | 1 | equemene | * C2 := C2 - W * V2' |
229 | 1 | equemene | * |
230 | 1 | equemene | CALL DGEMM( 'No transpose', 'Transpose', |
231 | 1 | equemene | $ LASTC, LASTV-K, K, |
232 | 1 | equemene | $ -ONE, WORK, LDWORK, V( K+1, 1 ), LDV, ONE, |
233 | 1 | equemene | $ C( 1, K+1 ), LDC ) |
234 | 1 | equemene | END IF |
235 | 1 | equemene | * |
236 | 1 | equemene | * W := W * V1' |
237 | 1 | equemene | * |
238 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'Transpose', 'Unit', |
239 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
240 | 1 | equemene | * |
241 | 1 | equemene | * C1 := C1 - W |
242 | 1 | equemene | * |
243 | 1 | equemene | DO 60 J = 1, K |
244 | 1 | equemene | DO 50 I = 1, LASTC |
245 | 1 | equemene | C( I, J ) = C( I, J ) - WORK( I, J ) |
246 | 1 | equemene | 50 CONTINUE |
247 | 1 | equemene | 60 CONTINUE |
248 | 1 | equemene | END IF |
249 | 1 | equemene | * |
250 | 1 | equemene | ELSE |
251 | 1 | equemene | * |
252 | 1 | equemene | * Let V = ( V1 ) |
253 | 1 | equemene | * ( V2 ) (last K rows) |
254 | 1 | equemene | * where V2 is unit upper triangular. |
255 | 1 | equemene | * |
256 | 1 | equemene | IF( LSAME( SIDE, 'L' ) ) THEN |
257 | 1 | equemene | * |
258 | 1 | equemene | * Form H * C or H' * C where C = ( C1 ) |
259 | 1 | equemene | * ( C2 ) |
260 | 1 | equemene | * |
261 | 1 | equemene | LASTV = MAX( K, ILADLR( M, K, V, LDV ) ) |
262 | 1 | equemene | LASTC = ILADLC( LASTV, N, C, LDC ) |
263 | 1 | equemene | * |
264 | 1 | equemene | * W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) |
265 | 1 | equemene | * |
266 | 1 | equemene | * W := C2' |
267 | 1 | equemene | * |
268 | 1 | equemene | DO 70 J = 1, K |
269 | 1 | equemene | CALL DCOPY( LASTC, C( LASTV-K+J, 1 ), LDC, |
270 | 1 | equemene | $ WORK( 1, J ), 1 ) |
271 | 1 | equemene | 70 CONTINUE |
272 | 1 | equemene | * |
273 | 1 | equemene | * W := W * V2 |
274 | 1 | equemene | * |
275 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'No transpose', 'Unit', |
276 | 1 | equemene | $ LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, |
277 | 1 | equemene | $ WORK, LDWORK ) |
278 | 1 | equemene | IF( LASTV.GT.K ) THEN |
279 | 1 | equemene | * |
280 | 1 | equemene | * W := W + C1'*V1 |
281 | 1 | equemene | * |
282 | 1 | equemene | CALL DGEMM( 'Transpose', 'No transpose', |
283 | 1 | equemene | $ LASTC, K, LASTV-K, ONE, C, LDC, V, LDV, |
284 | 1 | equemene | $ ONE, WORK, LDWORK ) |
285 | 1 | equemene | END IF |
286 | 1 | equemene | * |
287 | 1 | equemene | * W := W * T' or W * T |
288 | 1 | equemene | * |
289 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', TRANST, 'Non-unit', |
290 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
291 | 1 | equemene | * |
292 | 1 | equemene | * C := C - V * W' |
293 | 1 | equemene | * |
294 | 1 | equemene | IF( LASTV.GT.K ) THEN |
295 | 1 | equemene | * |
296 | 1 | equemene | * C1 := C1 - V1 * W' |
297 | 1 | equemene | * |
298 | 1 | equemene | CALL DGEMM( 'No transpose', 'Transpose', |
299 | 1 | equemene | $ LASTV-K, LASTC, K, -ONE, V, LDV, WORK, LDWORK, |
300 | 1 | equemene | $ ONE, C, LDC ) |
301 | 1 | equemene | END IF |
302 | 1 | equemene | * |
303 | 1 | equemene | * W := W * V2' |
304 | 1 | equemene | * |
305 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'Transpose', 'Unit', |
306 | 1 | equemene | $ LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, |
307 | 1 | equemene | $ WORK, LDWORK ) |
308 | 1 | equemene | * |
309 | 1 | equemene | * C2 := C2 - W' |
310 | 1 | equemene | * |
311 | 1 | equemene | DO 90 J = 1, K |
312 | 1 | equemene | DO 80 I = 1, LASTC |
313 | 1 | equemene | C( LASTV-K+J, I ) = C( LASTV-K+J, I ) - WORK(I, J) |
314 | 1 | equemene | 80 CONTINUE |
315 | 1 | equemene | 90 CONTINUE |
316 | 1 | equemene | * |
317 | 1 | equemene | ELSE IF( LSAME( SIDE, 'R' ) ) THEN |
318 | 1 | equemene | * |
319 | 1 | equemene | * Form C * H or C * H' where C = ( C1 C2 ) |
320 | 1 | equemene | * |
321 | 1 | equemene | LASTV = MAX( K, ILADLR( N, K, V, LDV ) ) |
322 | 1 | equemene | LASTC = ILADLR( M, LASTV, C, LDC ) |
323 | 1 | equemene | * |
324 | 1 | equemene | * W := C * V = (C1*V1 + C2*V2) (stored in WORK) |
325 | 1 | equemene | * |
326 | 1 | equemene | * W := C2 |
327 | 1 | equemene | * |
328 | 1 | equemene | DO 100 J = 1, K |
329 | 1 | equemene | CALL DCOPY( LASTC, C( 1, N-K+J ), 1, WORK( 1, J ), 1 ) |
330 | 1 | equemene | 100 CONTINUE |
331 | 1 | equemene | * |
332 | 1 | equemene | * W := W * V2 |
333 | 1 | equemene | * |
334 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'No transpose', 'Unit', |
335 | 1 | equemene | $ LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, |
336 | 1 | equemene | $ WORK, LDWORK ) |
337 | 1 | equemene | IF( LASTV.GT.K ) THEN |
338 | 1 | equemene | * |
339 | 1 | equemene | * W := W + C1 * V1 |
340 | 1 | equemene | * |
341 | 1 | equemene | CALL DGEMM( 'No transpose', 'No transpose', |
342 | 1 | equemene | $ LASTC, K, LASTV-K, ONE, C, LDC, V, LDV, |
343 | 1 | equemene | $ ONE, WORK, LDWORK ) |
344 | 1 | equemene | END IF |
345 | 1 | equemene | * |
346 | 1 | equemene | * W := W * T or W * T' |
347 | 1 | equemene | * |
348 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', TRANS, 'Non-unit', |
349 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
350 | 1 | equemene | * |
351 | 1 | equemene | * C := C - W * V' |
352 | 1 | equemene | * |
353 | 1 | equemene | IF( LASTV.GT.K ) THEN |
354 | 1 | equemene | * |
355 | 1 | equemene | * C1 := C1 - W * V1' |
356 | 1 | equemene | * |
357 | 1 | equemene | CALL DGEMM( 'No transpose', 'Transpose', |
358 | 1 | equemene | $ LASTC, LASTV-K, K, -ONE, WORK, LDWORK, V, LDV, |
359 | 1 | equemene | $ ONE, C, LDC ) |
360 | 1 | equemene | END IF |
361 | 1 | equemene | * |
362 | 1 | equemene | * W := W * V2' |
363 | 1 | equemene | * |
364 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'Transpose', 'Unit', |
365 | 1 | equemene | $ LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, |
366 | 1 | equemene | $ WORK, LDWORK ) |
367 | 1 | equemene | * |
368 | 1 | equemene | * C2 := C2 - W |
369 | 1 | equemene | * |
370 | 1 | equemene | DO 120 J = 1, K |
371 | 1 | equemene | DO 110 I = 1, LASTC |
372 | 1 | equemene | C( I, LASTV-K+J ) = C( I, LASTV-K+J ) - WORK(I, J) |
373 | 1 | equemene | 110 CONTINUE |
374 | 1 | equemene | 120 CONTINUE |
375 | 1 | equemene | END IF |
376 | 1 | equemene | END IF |
377 | 1 | equemene | * |
378 | 1 | equemene | ELSE IF( LSAME( STOREV, 'R' ) ) THEN |
379 | 1 | equemene | * |
380 | 1 | equemene | IF( LSAME( DIRECT, 'F' ) ) THEN |
381 | 1 | equemene | * |
382 | 1 | equemene | * Let V = ( V1 V2 ) (V1: first K columns) |
383 | 1 | equemene | * where V1 is unit upper triangular. |
384 | 1 | equemene | * |
385 | 1 | equemene | IF( LSAME( SIDE, 'L' ) ) THEN |
386 | 1 | equemene | * |
387 | 1 | equemene | * Form H * C or H' * C where C = ( C1 ) |
388 | 1 | equemene | * ( C2 ) |
389 | 1 | equemene | * |
390 | 1 | equemene | LASTV = MAX( K, ILADLC( K, M, V, LDV ) ) |
391 | 1 | equemene | LASTC = ILADLC( LASTV, N, C, LDC ) |
392 | 1 | equemene | * |
393 | 1 | equemene | * W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) |
394 | 1 | equemene | * |
395 | 1 | equemene | * W := C1' |
396 | 1 | equemene | * |
397 | 1 | equemene | DO 130 J = 1, K |
398 | 1 | equemene | CALL DCOPY( LASTC, C( J, 1 ), LDC, WORK( 1, J ), 1 ) |
399 | 1 | equemene | 130 CONTINUE |
400 | 1 | equemene | * |
401 | 1 | equemene | * W := W * V1' |
402 | 1 | equemene | * |
403 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'Transpose', 'Unit', |
404 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
405 | 1 | equemene | IF( LASTV.GT.K ) THEN |
406 | 1 | equemene | * |
407 | 1 | equemene | * W := W + C2'*V2' |
408 | 1 | equemene | * |
409 | 1 | equemene | CALL DGEMM( 'Transpose', 'Transpose', |
410 | 1 | equemene | $ LASTC, K, LASTV-K, |
411 | 1 | equemene | $ ONE, C( K+1, 1 ), LDC, V( 1, K+1 ), LDV, |
412 | 1 | equemene | $ ONE, WORK, LDWORK ) |
413 | 1 | equemene | END IF |
414 | 1 | equemene | * |
415 | 1 | equemene | * W := W * T' or W * T |
416 | 1 | equemene | * |
417 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', TRANST, 'Non-unit', |
418 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
419 | 1 | equemene | * |
420 | 1 | equemene | * C := C - V' * W' |
421 | 1 | equemene | * |
422 | 1 | equemene | IF( LASTV.GT.K ) THEN |
423 | 1 | equemene | * |
424 | 1 | equemene | * C2 := C2 - V2' * W' |
425 | 1 | equemene | * |
426 | 1 | equemene | CALL DGEMM( 'Transpose', 'Transpose', |
427 | 1 | equemene | $ LASTV-K, LASTC, K, |
428 | 1 | equemene | $ -ONE, V( 1, K+1 ), LDV, WORK, LDWORK, |
429 | 1 | equemene | $ ONE, C( K+1, 1 ), LDC ) |
430 | 1 | equemene | END IF |
431 | 1 | equemene | * |
432 | 1 | equemene | * W := W * V1 |
433 | 1 | equemene | * |
434 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'No transpose', 'Unit', |
435 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
436 | 1 | equemene | * |
437 | 1 | equemene | * C1 := C1 - W' |
438 | 1 | equemene | * |
439 | 1 | equemene | DO 150 J = 1, K |
440 | 1 | equemene | DO 140 I = 1, LASTC |
441 | 1 | equemene | C( J, I ) = C( J, I ) - WORK( I, J ) |
442 | 1 | equemene | 140 CONTINUE |
443 | 1 | equemene | 150 CONTINUE |
444 | 1 | equemene | * |
445 | 1 | equemene | ELSE IF( LSAME( SIDE, 'R' ) ) THEN |
446 | 1 | equemene | * |
447 | 1 | equemene | * Form C * H or C * H' where C = ( C1 C2 ) |
448 | 1 | equemene | * |
449 | 1 | equemene | LASTV = MAX( K, ILADLC( K, N, V, LDV ) ) |
450 | 1 | equemene | LASTC = ILADLR( M, LASTV, C, LDC ) |
451 | 1 | equemene | * |
452 | 1 | equemene | * W := C * V' = (C1*V1' + C2*V2') (stored in WORK) |
453 | 1 | equemene | * |
454 | 1 | equemene | * W := C1 |
455 | 1 | equemene | * |
456 | 1 | equemene | DO 160 J = 1, K |
457 | 1 | equemene | CALL DCOPY( LASTC, C( 1, J ), 1, WORK( 1, J ), 1 ) |
458 | 1 | equemene | 160 CONTINUE |
459 | 1 | equemene | * |
460 | 1 | equemene | * W := W * V1' |
461 | 1 | equemene | * |
462 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'Transpose', 'Unit', |
463 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
464 | 1 | equemene | IF( LASTV.GT.K ) THEN |
465 | 1 | equemene | * |
466 | 1 | equemene | * W := W + C2 * V2' |
467 | 1 | equemene | * |
468 | 1 | equemene | CALL DGEMM( 'No transpose', 'Transpose', |
469 | 1 | equemene | $ LASTC, K, LASTV-K, |
470 | 1 | equemene | $ ONE, C( 1, K+1 ), LDC, V( 1, K+1 ), LDV, |
471 | 1 | equemene | $ ONE, WORK, LDWORK ) |
472 | 1 | equemene | END IF |
473 | 1 | equemene | * |
474 | 1 | equemene | * W := W * T or W * T' |
475 | 1 | equemene | * |
476 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', TRANS, 'Non-unit', |
477 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
478 | 1 | equemene | * |
479 | 1 | equemene | * C := C - W * V |
480 | 1 | equemene | * |
481 | 1 | equemene | IF( LASTV.GT.K ) THEN |
482 | 1 | equemene | * |
483 | 1 | equemene | * C2 := C2 - W * V2 |
484 | 1 | equemene | * |
485 | 1 | equemene | CALL DGEMM( 'No transpose', 'No transpose', |
486 | 1 | equemene | $ LASTC, LASTV-K, K, |
487 | 1 | equemene | $ -ONE, WORK, LDWORK, V( 1, K+1 ), LDV, |
488 | 1 | equemene | $ ONE, C( 1, K+1 ), LDC ) |
489 | 1 | equemene | END IF |
490 | 1 | equemene | * |
491 | 1 | equemene | * W := W * V1 |
492 | 1 | equemene | * |
493 | 1 | equemene | CALL DTRMM( 'Right', 'Upper', 'No transpose', 'Unit', |
494 | 1 | equemene | $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) |
495 | 1 | equemene | * |
496 | 1 | equemene | * C1 := C1 - W |
497 | 1 | equemene | * |
498 | 1 | equemene | DO 180 J = 1, K |
499 | 1 | equemene | DO 170 I = 1, LASTC |
500 | 1 | equemene | C( I, J ) = C( I, J ) - WORK( I, J ) |
501 | 1 | equemene | 170 CONTINUE |
502 | 1 | equemene | 180 CONTINUE |
503 | 1 | equemene | * |
504 | 1 | equemene | END IF |
505 | 1 | equemene | * |
506 | 1 | equemene | ELSE |
507 | 1 | equemene | * |
508 | 1 | equemene | * Let V = ( V1 V2 ) (V2: last K columns) |
509 | 1 | equemene | * where V2 is unit lower triangular. |
510 | 1 | equemene | * |
511 | 1 | equemene | IF( LSAME( SIDE, 'L' ) ) THEN |
512 | 1 | equemene | * |
513 | 1 | equemene | * Form H * C or H' * C where C = ( C1 ) |
514 | 1 | equemene | * ( C2 ) |
515 | 1 | equemene | * |
516 | 1 | equemene | LASTV = MAX( K, ILADLC( K, M, V, LDV ) ) |
517 | 1 | equemene | LASTC = ILADLC( LASTV, N, C, LDC ) |
518 | 1 | equemene | * |
519 | 1 | equemene | * W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) |
520 | 1 | equemene | * |
521 | 1 | equemene | * W := C2' |
522 | 1 | equemene | * |
523 | 1 | equemene | DO 190 J = 1, K |
524 | 1 | equemene | CALL DCOPY( LASTC, C( LASTV-K+J, 1 ), LDC, |
525 | 1 | equemene | $ WORK( 1, J ), 1 ) |
526 | 1 | equemene | 190 CONTINUE |
527 | 1 | equemene | * |
528 | 1 | equemene | * W := W * V2' |
529 | 1 | equemene | * |
530 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'Transpose', 'Unit', |
531 | 1 | equemene | $ LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, |
532 | 1 | equemene | $ WORK, LDWORK ) |
533 | 1 | equemene | IF( LASTV.GT.K ) THEN |
534 | 1 | equemene | * |
535 | 1 | equemene | * W := W + C1'*V1' |
536 | 1 | equemene | * |
537 | 1 | equemene | CALL DGEMM( 'Transpose', 'Transpose', |
538 | 1 | equemene | $ LASTC, K, LASTV-K, ONE, C, LDC, V, LDV, |
539 | 1 | equemene | $ ONE, WORK, LDWORK ) |
540 | 1 | equemene | END IF |
541 | 1 | equemene | * |
542 | 1 | equemene | * W := W * T' or W * T |
543 | 1 | equemene | * |
544 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', TRANST, 'Non-unit', |
545 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
546 | 1 | equemene | * |
547 | 1 | equemene | * C := C - V' * W' |
548 | 1 | equemene | * |
549 | 1 | equemene | IF( LASTV.GT.K ) THEN |
550 | 1 | equemene | * |
551 | 1 | equemene | * C1 := C1 - V1' * W' |
552 | 1 | equemene | * |
553 | 1 | equemene | CALL DGEMM( 'Transpose', 'Transpose', |
554 | 1 | equemene | $ LASTV-K, LASTC, K, -ONE, V, LDV, WORK, LDWORK, |
555 | 1 | equemene | $ ONE, C, LDC ) |
556 | 1 | equemene | END IF |
557 | 1 | equemene | * |
558 | 1 | equemene | * W := W * V2 |
559 | 1 | equemene | * |
560 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'No transpose', 'Unit', |
561 | 1 | equemene | $ LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, |
562 | 1 | equemene | $ WORK, LDWORK ) |
563 | 1 | equemene | * |
564 | 1 | equemene | * C2 := C2 - W' |
565 | 1 | equemene | * |
566 | 1 | equemene | DO 210 J = 1, K |
567 | 1 | equemene | DO 200 I = 1, LASTC |
568 | 1 | equemene | C( LASTV-K+J, I ) = C( LASTV-K+J, I ) - WORK(I, J) |
569 | 1 | equemene | 200 CONTINUE |
570 | 1 | equemene | 210 CONTINUE |
571 | 1 | equemene | * |
572 | 1 | equemene | ELSE IF( LSAME( SIDE, 'R' ) ) THEN |
573 | 1 | equemene | * |
574 | 1 | equemene | * Form C * H or C * H' where C = ( C1 C2 ) |
575 | 1 | equemene | * |
576 | 1 | equemene | LASTV = MAX( K, ILADLC( K, N, V, LDV ) ) |
577 | 1 | equemene | LASTC = ILADLR( M, LASTV, C, LDC ) |
578 | 1 | equemene | * |
579 | 1 | equemene | * W := C * V' = (C1*V1' + C2*V2') (stored in WORK) |
580 | 1 | equemene | * |
581 | 1 | equemene | * W := C2 |
582 | 1 | equemene | * |
583 | 1 | equemene | DO 220 J = 1, K |
584 | 1 | equemene | CALL DCOPY( LASTC, C( 1, LASTV-K+J ), 1, |
585 | 1 | equemene | $ WORK( 1, J ), 1 ) |
586 | 1 | equemene | 220 CONTINUE |
587 | 1 | equemene | * |
588 | 1 | equemene | * W := W * V2' |
589 | 1 | equemene | * |
590 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'Transpose', 'Unit', |
591 | 1 | equemene | $ LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, |
592 | 1 | equemene | $ WORK, LDWORK ) |
593 | 1 | equemene | IF( LASTV.GT.K ) THEN |
594 | 1 | equemene | * |
595 | 1 | equemene | * W := W + C1 * V1' |
596 | 1 | equemene | * |
597 | 1 | equemene | CALL DGEMM( 'No transpose', 'Transpose', |
598 | 1 | equemene | $ LASTC, K, LASTV-K, ONE, C, LDC, V, LDV, |
599 | 1 | equemene | $ ONE, WORK, LDWORK ) |
600 | 1 | equemene | END IF |
601 | 1 | equemene | * |
602 | 1 | equemene | * W := W * T or W * T' |
603 | 1 | equemene | * |
604 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', TRANS, 'Non-unit', |
605 | 1 | equemene | $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) |
606 | 1 | equemene | * |
607 | 1 | equemene | * C := C - W * V |
608 | 1 | equemene | * |
609 | 1 | equemene | IF( LASTV.GT.K ) THEN |
610 | 1 | equemene | * |
611 | 1 | equemene | * C1 := C1 - W * V1 |
612 | 1 | equemene | * |
613 | 1 | equemene | CALL DGEMM( 'No transpose', 'No transpose', |
614 | 1 | equemene | $ LASTC, LASTV-K, K, -ONE, WORK, LDWORK, V, LDV, |
615 | 1 | equemene | $ ONE, C, LDC ) |
616 | 1 | equemene | END IF |
617 | 1 | equemene | * |
618 | 1 | equemene | * W := W * V2 |
619 | 1 | equemene | * |
620 | 1 | equemene | CALL DTRMM( 'Right', 'Lower', 'No transpose', 'Unit', |
621 | 1 | equemene | $ LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, |
622 | 1 | equemene | $ WORK, LDWORK ) |
623 | 1 | equemene | * |
624 | 1 | equemene | * C1 := C1 - W |
625 | 1 | equemene | * |
626 | 1 | equemene | DO 240 J = 1, K |
627 | 1 | equemene | DO 230 I = 1, LASTC |
628 | 1 | equemene | C( I, LASTV-K+J ) = C( I, LASTV-K+J ) - WORK(I, J) |
629 | 1 | equemene | 230 CONTINUE |
630 | 1 | equemene | 240 CONTINUE |
631 | 1 | equemene | * |
632 | 1 | equemene | END IF |
633 | 1 | equemene | * |
634 | 1 | equemene | END IF |
635 | 1 | equemene | END IF |
636 | 1 | equemene | * |
637 | 1 | equemene | RETURN |
638 | 1 | equemene | * |
639 | 1 | equemene | * End of DLARFB |
640 | 1 | equemene | * |
641 | 1 | equemene | END |