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1.7 bertrand 1: *> \brief \b ZTPTTF
1.1 bertrand 2: *
1.7 bertrand 3: * =========== DOCUMENTATION ===========
1.1 bertrand 4: *
1.7 bertrand 5: * Online html documentation available at
6: * http://www.netlib.org/lapack/explore-html/
1.1 bertrand 7: *
1.7 bertrand 8: *> \htmlonly
9: *> Download ZTPTTF + dependencies
10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ztpttf.f">
11: *> [TGZ]</a>
12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ztpttf.f">
13: *> [ZIP]</a>
14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ztpttf.f">
15: *> [TXT]</a>
16: *> \endhtmlonly
17: *
18: * Definition:
19: * ===========
20: *
21: * SUBROUTINE ZTPTTF( TRANSR, UPLO, N, AP, ARF, INFO )
22: *
23: * .. Scalar Arguments ..
24: * CHARACTER TRANSR, UPLO
25: * INTEGER INFO, N
26: * ..
27: * .. Array Arguments ..
28: * COMPLEX*16 AP( 0: * ), ARF( 0: * )
29: *
30: *
31: *> \par Purpose:
32: * =============
33: *>
34: *> \verbatim
35: *>
36: *> ZTPTTF copies a triangular matrix A from standard packed format (TP)
37: *> to rectangular full packed format (TF).
38: *> \endverbatim
39: *
40: * Arguments:
41: * ==========
42: *
43: *> \param[in] TRANSR
44: *> \verbatim
45: *> TRANSR is CHARACTER*1
46: *> = 'N': ARF in Normal format is wanted;
47: *> = 'C': ARF in Conjugate-transpose format is wanted.
48: *> \endverbatim
49: *>
50: *> \param[in] UPLO
51: *> \verbatim
52: *> UPLO is CHARACTER*1
53: *> = 'U': A is upper triangular;
54: *> = 'L': A is lower triangular.
55: *> \endverbatim
56: *>
57: *> \param[in] N
58: *> \verbatim
59: *> N is INTEGER
60: *> The order of the matrix A. N >= 0.
61: *> \endverbatim
62: *>
63: *> \param[in] AP
64: *> \verbatim
65: *> AP is COMPLEX*16 array, dimension ( N*(N+1)/2 ),
66: *> On entry, the upper or lower triangular matrix A, packed
67: *> columnwise in a linear array. The j-th column of A is stored
68: *> in the array AP as follows:
69: *> if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
70: *> if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
71: *> \endverbatim
72: *>
73: *> \param[out] ARF
74: *> \verbatim
75: *> ARF is COMPLEX*16 array, dimension ( N*(N+1)/2 ),
76: *> On exit, the upper or lower triangular matrix A stored in
77: *> RFP format. For a further discussion see Notes below.
78: *> \endverbatim
79: *>
80: *> \param[out] INFO
81: *> \verbatim
82: *> INFO is INTEGER
83: *> = 0: successful exit
84: *> < 0: if INFO = -i, the i-th argument had an illegal value
85: *> \endverbatim
86: *
87: * Authors:
88: * ========
89: *
90: *> \author Univ. of Tennessee
91: *> \author Univ. of California Berkeley
92: *> \author Univ. of Colorado Denver
93: *> \author NAG Ltd.
94: *
95: *> \date November 2011
96: *
97: *> \ingroup complex16OTHERcomputational
98: *
99: *> \par Further Details:
100: * =====================
101: *>
102: *> \verbatim
103: *>
104: *> We first consider Standard Packed Format when N is even.
105: *> We give an example where N = 6.
106: *>
107: *> AP is Upper AP is Lower
108: *>
109: *> 00 01 02 03 04 05 00
110: *> 11 12 13 14 15 10 11
111: *> 22 23 24 25 20 21 22
112: *> 33 34 35 30 31 32 33
113: *> 44 45 40 41 42 43 44
114: *> 55 50 51 52 53 54 55
115: *>
116: *>
117: *> Let TRANSR = 'N'. RFP holds AP as follows:
118: *> For UPLO = 'U' the upper trapezoid A(0:5,0:2) consists of the last
119: *> three columns of AP upper. The lower triangle A(4:6,0:2) consists of
120: *> conjugate-transpose of the first three columns of AP upper.
121: *> For UPLO = 'L' the lower trapezoid A(1:6,0:2) consists of the first
122: *> three columns of AP lower. The upper triangle A(0:2,0:2) consists of
123: *> conjugate-transpose of the last three columns of AP lower.
124: *> To denote conjugate we place -- above the element. This covers the
125: *> case N even and TRANSR = 'N'.
126: *>
127: *> RFP A RFP A
128: *>
129: *> -- -- --
130: *> 03 04 05 33 43 53
131: *> -- --
132: *> 13 14 15 00 44 54
133: *> --
134: *> 23 24 25 10 11 55
135: *>
136: *> 33 34 35 20 21 22
137: *> --
138: *> 00 44 45 30 31 32
139: *> -- --
140: *> 01 11 55 40 41 42
141: *> -- -- --
142: *> 02 12 22 50 51 52
143: *>
144: *> Now let TRANSR = 'C'. RFP A in both UPLO cases is just the conjugate-
145: *> transpose of RFP A above. One therefore gets:
146: *>
147: *>
148: *> RFP A RFP A
149: *>
150: *> -- -- -- -- -- -- -- -- -- --
151: *> 03 13 23 33 00 01 02 33 00 10 20 30 40 50
152: *> -- -- -- -- -- -- -- -- -- --
153: *> 04 14 24 34 44 11 12 43 44 11 21 31 41 51
154: *> -- -- -- -- -- -- -- -- -- --
155: *> 05 15 25 35 45 55 22 53 54 55 22 32 42 52
156: *>
157: *>
158: *> We next consider Standard Packed Format when N is odd.
159: *> We give an example where N = 5.
160: *>
161: *> AP is Upper AP is Lower
162: *>
163: *> 00 01 02 03 04 00
164: *> 11 12 13 14 10 11
165: *> 22 23 24 20 21 22
166: *> 33 34 30 31 32 33
167: *> 44 40 41 42 43 44
168: *>
169: *>
170: *> Let TRANSR = 'N'. RFP holds AP as follows:
171: *> For UPLO = 'U' the upper trapezoid A(0:4,0:2) consists of the last
172: *> three columns of AP upper. The lower triangle A(3:4,0:1) consists of
173: *> conjugate-transpose of the first two columns of AP upper.
174: *> For UPLO = 'L' the lower trapezoid A(0:4,0:2) consists of the first
175: *> three columns of AP lower. The upper triangle A(0:1,1:2) consists of
176: *> conjugate-transpose of the last two columns of AP lower.
177: *> To denote conjugate we place -- above the element. This covers the
178: *> case N odd and TRANSR = 'N'.
179: *>
180: *> RFP A RFP A
181: *>
182: *> -- --
183: *> 02 03 04 00 33 43
184: *> --
185: *> 12 13 14 10 11 44
186: *>
187: *> 22 23 24 20 21 22
188: *> --
189: *> 00 33 34 30 31 32
190: *> -- --
191: *> 01 11 44 40 41 42
192: *>
193: *> Now let TRANSR = 'C'. RFP A in both UPLO cases is just the conjugate-
194: *> transpose of RFP A above. One therefore gets:
195: *>
196: *>
197: *> RFP A RFP A
198: *>
199: *> -- -- -- -- -- -- -- -- --
200: *> 02 12 22 00 01 00 10 20 30 40 50
201: *> -- -- -- -- -- -- -- -- --
202: *> 03 13 23 33 11 33 11 21 31 41 51
203: *> -- -- -- -- -- -- -- -- --
204: *> 04 14 24 34 44 43 44 22 32 42 52
205: *> \endverbatim
206: *>
207: * =====================================================================
208: SUBROUTINE ZTPTTF( TRANSR, UPLO, N, AP, ARF, INFO )
209: *
210: * -- LAPACK computational routine (version 3.4.0) --
1.1 bertrand 211: * -- LAPACK is a software package provided by Univ. of Tennessee, --
212: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
1.7 bertrand 213: * November 2011
1.1 bertrand 214: *
215: * .. Scalar Arguments ..
216: CHARACTER TRANSR, UPLO
217: INTEGER INFO, N
218: * ..
219: * .. Array Arguments ..
220: COMPLEX*16 AP( 0: * ), ARF( 0: * )
221: *
222: * =====================================================================
223: *
224: * .. Parameters ..
225: * ..
226: * .. Local Scalars ..
227: LOGICAL LOWER, NISODD, NORMALTRANSR
228: INTEGER N1, N2, K, NT
229: INTEGER I, J, IJ
230: INTEGER IJP, JP, LDA, JS
231: * ..
232: * .. External Functions ..
233: LOGICAL LSAME
234: EXTERNAL LSAME
235: * ..
236: * .. External Subroutines ..
237: EXTERNAL XERBLA
238: * ..
239: * .. Intrinsic Functions ..
240: INTRINSIC DCONJG, MOD
241: * ..
242: * .. Executable Statements ..
243: *
244: * Test the input parameters.
245: *
246: INFO = 0
247: NORMALTRANSR = LSAME( TRANSR, 'N' )
248: LOWER = LSAME( UPLO, 'L' )
249: IF( .NOT.NORMALTRANSR .AND. .NOT.LSAME( TRANSR, 'C' ) ) THEN
250: INFO = -1
251: ELSE IF( .NOT.LOWER .AND. .NOT.LSAME( UPLO, 'U' ) ) THEN
252: INFO = -2
253: ELSE IF( N.LT.0 ) THEN
254: INFO = -3
255: END IF
256: IF( INFO.NE.0 ) THEN
257: CALL XERBLA( 'ZTPTTF', -INFO )
258: RETURN
259: END IF
260: *
261: * Quick return if possible
262: *
263: IF( N.EQ.0 )
1.6 bertrand 264: $ RETURN
1.1 bertrand 265: *
266: IF( N.EQ.1 ) THEN
267: IF( NORMALTRANSR ) THEN
268: ARF( 0 ) = AP( 0 )
269: ELSE
270: ARF( 0 ) = DCONJG( AP( 0 ) )
271: END IF
272: RETURN
273: END IF
274: *
275: * Size of array ARF(0:NT-1)
276: *
277: NT = N*( N+1 ) / 2
278: *
279: * Set N1 and N2 depending on LOWER
280: *
281: IF( LOWER ) THEN
282: N2 = N / 2
283: N1 = N - N2
284: ELSE
285: N1 = N / 2
286: N2 = N - N1
287: END IF
288: *
289: * If N is odd, set NISODD = .TRUE.
290: * If N is even, set K = N/2 and NISODD = .FALSE.
291: *
292: * set lda of ARF^C; ARF^C is (0:(N+1)/2-1,0:N-noe)
293: * where noe = 0 if n is even, noe = 1 if n is odd
294: *
295: IF( MOD( N, 2 ).EQ.0 ) THEN
296: K = N / 2
297: NISODD = .FALSE.
298: LDA = N + 1
299: ELSE
300: NISODD = .TRUE.
301: LDA = N
302: END IF
303: *
304: * ARF^C has lda rows and n+1-noe cols
305: *
306: IF( .NOT.NORMALTRANSR )
1.6 bertrand 307: $ LDA = ( N+1 ) / 2
1.1 bertrand 308: *
309: * start execution: there are eight cases
310: *
311: IF( NISODD ) THEN
312: *
313: * N is odd
314: *
315: IF( NORMALTRANSR ) THEN
316: *
317: * N is odd and TRANSR = 'N'
318: *
319: IF( LOWER ) THEN
320: *
321: * SRPA for LOWER, NORMAL and N is odd ( a(0:n-1,0:n1-1) )
322: * T1 -> a(0,0), T2 -> a(0,1), S -> a(n1,0)
323: * T1 -> a(0), T2 -> a(n), S -> a(n1); lda = n
324: *
325: IJP = 0
326: JP = 0
327: DO J = 0, N2
328: DO I = J, N - 1
329: IJ = I + JP
330: ARF( IJ ) = AP( IJP )
331: IJP = IJP + 1
332: END DO
333: JP = JP + LDA
334: END DO
335: DO I = 0, N2 - 1
336: DO J = 1 + I, N2
337: IJ = I + J*LDA
338: ARF( IJ ) = DCONJG( AP( IJP ) )
339: IJP = IJP + 1
340: END DO
341: END DO
342: *
343: ELSE
344: *
345: * SRPA for UPPER, NORMAL and N is odd ( a(0:n-1,0:n2-1)
346: * T1 -> a(n1+1,0), T2 -> a(n1,0), S -> a(0,0)
347: * T1 -> a(n2), T2 -> a(n1), S -> a(0)
348: *
349: IJP = 0
350: DO J = 0, N1 - 1
351: IJ = N2 + J
352: DO I = 0, J
353: ARF( IJ ) = DCONJG( AP( IJP ) )
354: IJP = IJP + 1
355: IJ = IJ + LDA
356: END DO
357: END DO
358: JS = 0
359: DO J = N1, N - 1
360: IJ = JS
361: DO IJ = JS, JS + J
362: ARF( IJ ) = AP( IJP )
363: IJP = IJP + 1
364: END DO
365: JS = JS + LDA
366: END DO
367: *
368: END IF
369: *
370: ELSE
371: *
372: * N is odd and TRANSR = 'C'
373: *
374: IF( LOWER ) THEN
375: *
376: * SRPA for LOWER, TRANSPOSE and N is odd
377: * T1 -> A(0,0) , T2 -> A(1,0) , S -> A(0,n1)
378: * T1 -> a(0+0) , T2 -> a(1+0) , S -> a(0+n1*n1); lda=n1
379: *
380: IJP = 0
381: DO I = 0, N2
382: DO IJ = I*( LDA+1 ), N*LDA - 1, LDA
383: ARF( IJ ) = DCONJG( AP( IJP ) )
384: IJP = IJP + 1
385: END DO
386: END DO
387: JS = 1
388: DO J = 0, N2 - 1
389: DO IJ = JS, JS + N2 - J - 1
390: ARF( IJ ) = AP( IJP )
391: IJP = IJP + 1
392: END DO
393: JS = JS + LDA + 1
394: END DO
395: *
396: ELSE
397: *
398: * SRPA for UPPER, TRANSPOSE and N is odd
399: * T1 -> A(0,n1+1), T2 -> A(0,n1), S -> A(0,0)
400: * T1 -> a(n2*n2), T2 -> a(n1*n2), S -> a(0); lda = n2
401: *
402: IJP = 0
403: JS = N2*LDA
404: DO J = 0, N1 - 1
405: DO IJ = JS, JS + J
406: ARF( IJ ) = AP( IJP )
407: IJP = IJP + 1
408: END DO
409: JS = JS + LDA
410: END DO
411: DO I = 0, N1
412: DO IJ = I, I + ( N1+I )*LDA, LDA
413: ARF( IJ ) = DCONJG( AP( IJP ) )
414: IJP = IJP + 1
415: END DO
416: END DO
417: *
418: END IF
419: *
420: END IF
421: *
422: ELSE
423: *
424: * N is even
425: *
426: IF( NORMALTRANSR ) THEN
427: *
428: * N is even and TRANSR = 'N'
429: *
430: IF( LOWER ) THEN
431: *
432: * SRPA for LOWER, NORMAL, and N is even ( a(0:n,0:k-1) )
433: * T1 -> a(1,0), T2 -> a(0,0), S -> a(k+1,0)
434: * T1 -> a(1), T2 -> a(0), S -> a(k+1)
435: *
436: IJP = 0
437: JP = 0
438: DO J = 0, K - 1
439: DO I = J, N - 1
440: IJ = 1 + I + JP
441: ARF( IJ ) = AP( IJP )
442: IJP = IJP + 1
443: END DO
444: JP = JP + LDA
445: END DO
446: DO I = 0, K - 1
447: DO J = I, K - 1
448: IJ = I + J*LDA
449: ARF( IJ ) = DCONJG( AP( IJP ) )
450: IJP = IJP + 1
451: END DO
452: END DO
453: *
454: ELSE
455: *
456: * SRPA for UPPER, NORMAL, and N is even ( a(0:n,0:k-1) )
457: * T1 -> a(k+1,0) , T2 -> a(k,0), S -> a(0,0)
458: * T1 -> a(k+1), T2 -> a(k), S -> a(0)
459: *
460: IJP = 0
461: DO J = 0, K - 1
462: IJ = K + 1 + J
463: DO I = 0, J
464: ARF( IJ ) = DCONJG( AP( IJP ) )
465: IJP = IJP + 1
466: IJ = IJ + LDA
467: END DO
468: END DO
469: JS = 0
470: DO J = K, N - 1
471: IJ = JS
472: DO IJ = JS, JS + J
473: ARF( IJ ) = AP( IJP )
474: IJP = IJP + 1
475: END DO
476: JS = JS + LDA
477: END DO
478: *
479: END IF
480: *
481: ELSE
482: *
483: * N is even and TRANSR = 'C'
484: *
485: IF( LOWER ) THEN
486: *
487: * SRPA for LOWER, TRANSPOSE and N is even (see paper)
488: * T1 -> B(0,1), T2 -> B(0,0), S -> B(0,k+1)
489: * T1 -> a(0+k), T2 -> a(0+0), S -> a(0+k*(k+1)); lda=k
490: *
491: IJP = 0
492: DO I = 0, K - 1
493: DO IJ = I + ( I+1 )*LDA, ( N+1 )*LDA - 1, LDA
494: ARF( IJ ) = DCONJG( AP( IJP ) )
495: IJP = IJP + 1
496: END DO
497: END DO
498: JS = 0
499: DO J = 0, K - 1
500: DO IJ = JS, JS + K - J - 1
501: ARF( IJ ) = AP( IJP )
502: IJP = IJP + 1
503: END DO
504: JS = JS + LDA + 1
505: END DO
506: *
507: ELSE
508: *
509: * SRPA for UPPER, TRANSPOSE and N is even (see paper)
510: * T1 -> B(0,k+1), T2 -> B(0,k), S -> B(0,0)
511: * T1 -> a(0+k*(k+1)), T2 -> a(0+k*k), S -> a(0+0)); lda=k
512: *
513: IJP = 0
514: JS = ( K+1 )*LDA
515: DO J = 0, K - 1
516: DO IJ = JS, JS + J
517: ARF( IJ ) = AP( IJP )
518: IJP = IJP + 1
519: END DO
520: JS = JS + LDA
521: END DO
522: DO I = 0, K - 1
523: DO IJ = I, I + ( K+I )*LDA, LDA
524: ARF( IJ ) = DCONJG( AP( IJP ) )
525: IJP = IJP + 1
526: END DO
527: END DO
528: *
529: END IF
530: *
531: END IF
532: *
533: END IF
534: *
535: RETURN
536: *
537: * End of ZTPTTF
538: *
539: END