1 //
2 //  Copyright (c) 2018-2019, Cem Bassoy, [email protected]
3 //
4 //  Distributed under the Boost Software License, Version 1.0. (See
5 //  accompanying file LICENSE_1_0.txt or copy at
6 //  http://www.boost.org/LICENSE_1_0.txt)
7 //
8 //  The authors gratefully acknowledge the support of
9 //  Fraunhofer IOSB, Ettlingen, Germany
10 //
11 
12 
13 #ifndef BOOST_UBLAS_TENSOR_MULTIPLICATION
14 #define BOOST_UBLAS_TENSOR_MULTIPLICATION
15 
16 #include <cassert>
17 
18 namespace boost {
19 namespace numeric {
20 namespace ublas {
21 namespace detail {
22 namespace recursive {
23 
24 
25 /** @brief Computes the tensor-times-tensor product for q contraction modes
26  *
27  * Implements C[i1,...,ir,j1,...,js] = sum( A[i1,...,ir+q] * B[j1,...,js+q]  )
28  *
29  * nc[x]         = na[phia[x]  ] for 1 <= x <= r
30  * nc[r+x]       = nb[phib[x]  ] for 1 <= x <= s
31  * na[phia[r+x]] = nb[phib[s+x]] for 1 <= x <= q
32  *
33  * @note is used in function ttt
34  *
35  * @param k  zero-based recursion level starting with 0
36  * @param r  number of non-contraction indices of A
37  * @param s  number of non-contraction indices of B
38  * @param q  number of contraction indices with q > 0
39  * @param phia pointer to the permutation tuple of length q+r for A
40  * @param phib pointer to the permutation tuple of length q+s for B
41  * @param c  pointer to the output tensor C with rank(A)=r+s
42  * @param nc pointer to the extents of tensor C
43  * @param wc pointer to the strides of tensor C
44  * @param a  pointer to the first input tensor with rank(A)=r+q
45  * @param na pointer to the extents of the first input tensor A
46  * @param wa pointer to the strides of the first input tensor A
47  * @param b  pointer to the second input tensor B with rank(B)=s+q
48  * @param nb pointer to the extents of the second input tensor B
49  * @param wb pointer to the strides of the second input tensor B
50 */
51 
52 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttt(SizeType const k,SizeType const r,SizeType const s,SizeType const q,SizeType const * const phia,SizeType const * const phib,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)53 void ttt(SizeType const k,
54          SizeType const r, SizeType const s, SizeType const q,
55          SizeType const*const phia, SizeType const*const phib,
56          PointerOut c, SizeType const*const nc, SizeType const*const wc,
57          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
58          PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
59 {
60 	if(k < r)
61 	{
62 		assert(nc[k] == na[phia[k]-1]);
63 		for(size_t ic = 0u; ic < nc[k]; a += wa[phia[k]-1], c += wc[k], ++ic)
64 			ttt(k+1, r, s, q,  phia,phib,  c, nc, wc,   a, na, wa,   b, nb, wb);
65 	}
66 	else if(k < r+s)
67 	{
68 		assert(nc[k] == nb[phib[k-r]-1]);
69 		for(size_t ic = 0u; ic < nc[k]; b += wb[phib[k-r]-1], c += wc[k], ++ic)
70 			ttt(k+1, r, s, q,  phia, phib,    c, nc, wc,   a, na, wa,   b, nb, wb);
71 	}
72 	else if(k < r+s+q-1)
73 	{
74 		assert(na[phia[k-s]-1] == nb[phib[k-r]-1]);
75 		for(size_t ia = 0u; ia < na[phia[k-s]-1]; a += wa[phia[k-s]-1], b += wb[phib[k-r]-1], ++ia)
76 			ttt(k+1, r, s, q,  phia, phib,  c, nc, wc,   a, na, wa,   b, nb, wb);
77 	}
78 	else
79 	{
80 		assert(na[phia[k-s]-1] == nb[phib[k-r]-1]);
81 		for(size_t ia = 0u; ia < na[phia[k-s]-1]; a += wa[phia[k-s]-1], b += wb[phib[k-r]-1], ++ia)
82 			*c += *a * *b;
83 	}
84 }
85 
86 
87 
88 
89 /** @brief Computes the tensor-times-tensor product for q contraction modes
90  *
91  * Implements C[i1,...,ir,j1,...,js] = sum( A[i1,...,ir+q] * B[j1,...,js+q]  )
92  *
93  * @note no permutation tuple is used
94  *
95  * nc[x]   = na[x  ] for 1 <= x <= r
96  * nc[r+x] = nb[x  ] for 1 <= x <= s
97  * na[r+x] = nb[s+x] for 1 <= x <= q
98  *
99  * @note is used in function ttt
100  *
101  * @param k  zero-based recursion level starting with 0
102  * @param r  number of non-contraction indices of A
103  * @param s  number of non-contraction indices of B
104  * @param q  number of contraction indices with q > 0
105  * @param c  pointer to the output tensor C with rank(A)=r+s
106  * @param nc pointer to the extents of tensor C
107  * @param wc pointer to the strides of tensor C
108  * @param a  pointer to the first input tensor with rank(A)=r+q
109  * @param na pointer to the extents of the first input tensor A
110  * @param wa pointer to the strides of the first input tensor A
111  * @param b  pointer to the second input tensor B with rank(B)=s+q
112  * @param nb pointer to the extents of the second input tensor B
113  * @param wb pointer to the strides of the second input tensor B
114 */
115 
116 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttt(SizeType const k,SizeType const r,SizeType const s,SizeType const q,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)117 void ttt(SizeType const k,
118          SizeType const r, SizeType const s, SizeType const q,
119          PointerOut c, SizeType const*const nc, SizeType const*const wc,
120          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
121          PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
122 {
123 	if(k < r)
124 	{
125 		assert(nc[k] == na[k]);
126 		for(size_t ic = 0u; ic < nc[k]; a += wa[k], c += wc[k], ++ic)
127 			ttt(k+1, r, s, q,  c, nc, wc,   a, na, wa,   b, nb, wb);
128 	}
129 	else if(k < r+s)
130 	{
131 		assert(nc[k] == nb[k-r]);
132 		for(size_t ic = 0u; ic < nc[k]; b += wb[k-r], c += wc[k], ++ic)
133 			ttt(k+1, r, s, q,  c, nc, wc,   a, na, wa,   b, nb, wb);
134 	}
135 	else if(k < r+s+q-1)
136 	{
137 		assert(na[k-s] == nb[k-r]);
138 		for(size_t ia = 0u; ia < na[k-s]; a += wa[k-s], b += wb[k-r], ++ia)
139 			ttt(k+1, r, s, q,  c, nc, wc,   a, na, wa,   b, nb, wb);
140 	}
141 	else
142 	{
143 		assert(na[k-s] == nb[k-r]);
144 		for(size_t ia = 0u; ia < na[k-s]; a += wa[k-s], b += wb[k-r], ++ia)
145 			*c += *a * *b;
146 	}
147 }
148 
149 
150 /** @brief Computes the tensor-times-matrix product for the contraction mode m > 0
151  *
152  * Implements C[i1,i2,...,im-1,j,im+1,...,ip] = sum(A[i1,i2,...,im,...,ip] * B[j,im])
153  *
154  * @note is used in function ttm
155  *
156  * @param m  zero-based contraction mode with 0<m<p
157  * @param r  zero-based recursion level starting with p-1
158  * @param c  pointer to the output tensor
159  * @param nc pointer to the extents of tensor c
160  * @param wc pointer to the strides of tensor c
161  * @param a  pointer to the first input tensor
162  * @param na pointer to the extents of input tensor a
163  * @param wa pointer to the strides of input tensor a
164  * @param b  pointer to the second input tensor
165  * @param nb pointer to the extents of input tensor b
166  * @param wb pointer to the strides of input tensor b
167 */
168 
169 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttm(SizeType const m,SizeType const r,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)170 void ttm(SizeType const m,  SizeType const r,
171          PointerOut c, SizeType const*const nc, SizeType const*const wc,
172          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
173          PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
174 {
175 
176 	if(r == m) {
177 		ttm(m, r-1, c, nc, wc,    a, na, wa,    b, nb, wb);
178 	}
179 	else if(r == 0){
180 		for(auto i0 = 0ul; i0 < nc[0]; c += wc[0], a += wa[0], ++i0) {
181 			auto cm = c;
182 			auto b0 = b;
183 			for(auto i0 = 0ul; i0 < nc[m]; cm += wc[m], b0 += wb[0], ++i0){
184 				auto am = a;
185 				auto b1 = b0;
186 				for(auto i1 = 0ul; i1 < nb[1]; am += wa[m], b1 += wb[1], ++i1)
187 					*cm += *am * *b1;
188 			}
189 		}
190 	}
191 
192 	else{
193 		for(auto i = 0ul; i < na[r]; c += wc[r], a += wa[r], ++i)
194 			ttm(m, r-1, c, nc, wc,    a, na, wa,    b, nb, wb);
195 	}
196 }
197 
198 /** @brief Computes the tensor-times-matrix product for the contraction mode m = 0
199  *
200  * Implements C[j,i2,...,ip] = sum(A[i1,i2,...,ip] * B[j,i1])
201  *
202  * @note is used in function ttm
203  *
204  * @param m  zero-based contraction mode with 0<m<p
205  * @param r  zero-based recursion level starting with p-1
206  * @param c  pointer to the output tensor
207  * @param nc pointer to the extents of tensor c
208  * @param wc pointer to the strides of tensor c
209  * @param a  pointer to the first input tensor
210  * @param na pointer to the extents of input tensor a
211  * @param wa pointer to the strides of input tensor a
212  * @param b  pointer to the second input tensor
213  * @param nb pointer to the extents of input tensor b
214  * @param wb pointer to the strides of input tensor b
215 */
216 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttm0(SizeType const r,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)217 void ttm0( SizeType const r,
218            PointerOut c, SizeType const*const nc, SizeType const*const wc,
219            PointerIn1 a, SizeType const*const na, SizeType const*const wa,
220            PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
221 {
222 
223 	if(r > 1){
224 		for(auto i = 0ul; i < na[r]; c += wc[r], a += wa[r], ++i)
225 			ttm0(r-1, c, nc, wc,    a, na, wa,    b, nb, wb);
226 	}
227 	else{
228 		for(auto i1 = 0ul; i1 < nc[1]; c += wc[1], a += wa[1], ++i1) {
229 			auto cm = c;
230 			auto b0 = b;
231 			// r == m == 0
232 			for(auto i0 = 0ul; i0 < nc[0]; cm += wc[0], b0 += wb[0], ++i0){
233 
234 				auto am = a;
235 				auto b1 = b0;
236 				for(auto i1 = 0u; i1 < nb[1]; am += wa[0], b1 += wb[1], ++i1){
237 
238 					*cm += *am * *b1;
239 				}
240 			}
241 		}
242 	}
243 }
244 
245 
246 //////////////////////////////////////////////////////////////////////////////////////////
247 //////////////////////////////////////////////////////////////////////////////////////////
248 //////////////////////////////////////////////////////////////////////////////////////////
249 //////////////////////////////////////////////////////////////////////////////////////////
250 
251 
252 /** @brief Computes the tensor-times-vector product for the contraction mode m > 0
253  *
254  * Implements C[i1,i2,...,im-1,im+1,...,ip] = sum(A[i1,i2,...,im,...,ip] * b[im])
255  *
256  * @note is used in function ttv
257  *
258  * @param m  zero-based contraction mode with 0<m<p
259  * @param r  zero-based recursion level starting with p-1 for tensor A
260  * @param q  zero-based recursion level starting with p-1 for tensor C
261  * @param c  pointer to the output tensor
262  * @param nc pointer to the extents of tensor c
263  * @param wc pointer to the strides of tensor c
264  * @param a  pointer to the first input tensor
265  * @param na pointer to the extents of input tensor a
266  * @param wa pointer to the strides of input tensor a
267  * @param b  pointer to the second input tensor
268 */
269 
270 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttv(SizeType const m,SizeType const r,SizeType const q,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b)271 void ttv( SizeType const m, SizeType const r, SizeType const q,
272           PointerOut c, SizeType const*const nc, SizeType const*const wc,
273           PointerIn1 a, SizeType const*const na, SizeType const*const wa,
274           PointerIn2 b)
275 {
276 
277 	if(r == m) {
278 		ttv(m, r-1, q, c, nc, wc,    a, na, wa,    b);
279 	}
280 	else if(r == 0){
281 		for(auto i0 = 0u; i0 < na[0]; c += wc[0], a += wa[0], ++i0) {
282 			auto c1 = c; auto a1 = a; auto b1 = b;
283 			for(auto im = 0u; im < na[m]; a1 += wa[m], ++b1, ++im)
284 				*c1 += *a1 * *b1;
285 		}
286 	}
287 	else{
288 		for(auto i = 0u; i < na[r]; c += wc[q], a += wa[r], ++i)
289 			ttv(m, r-1, q-1, c, nc, wc,    a, na, wa,    b);
290 	}
291 }
292 
293 
294 /** @brief Computes the tensor-times-vector product for the contraction mode m = 0
295  *
296  * Implements C[i2,...,ip] = sum(A[i1,...,ip] * b[i1])
297  *
298  * @note is used in function ttv
299  *
300  * @param m  zero-based contraction mode with m=0
301  * @param r  zero-based recursion level starting with p-1
302  * @param c  pointer to the output tensor
303  * @param nc pointer to the extents of tensor c
304  * @param wc pointer to the strides of tensor c
305  * @param a  pointer to the first input tensor
306  * @param na pointer to the extents of input tensor a
307  * @param wa pointer to the strides of input tensor a
308  * @param b  pointer to the second input tensor
309 */
310 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttv0(SizeType const r,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b)311 void ttv0(SizeType const r,
312           PointerOut c, SizeType const*const nc, SizeType const*const wc,
313           PointerIn1 a, SizeType const*const na, SizeType const*const wa,
314           PointerIn2 b)
315 {
316 
317 	if(r > 1){
318 		for(auto i = 0u; i < na[r]; c += wc[r-1], a += wa[r], ++i)
319 			ttv0(r-1, c, nc, wc,    a, na, wa,    b);
320 	}
321 	else{
322 		for(auto i1 = 0u; i1 < na[1]; c += wc[0], a += wa[1], ++i1)
323 		{
324 			auto c1 = c; auto a1 = a; auto b1 = b;
325 			for(auto i0 = 0u; i0 < na[0]; a1 += wa[0], ++b1, ++i0)
326 				*c1 += *a1 * *b1;
327 		}
328 	}
329 }
330 
331 
332 /** @brief Computes the matrix-times-vector product
333  *
334  * Implements C[i1] = sum(A[i1,i2] * b[i2]) or C[i2] = sum(A[i1,i2] * b[i1])
335  *
336  * @note is used in function ttv
337  *
338  * @param[in]  m  zero-based contraction mode with m=0 or m=1
339  * @param[out] c  pointer to the output tensor C
340  * @param[in]  nc pointer to the extents of tensor C
341  * @param[in]  wc pointer to the strides of tensor C
342  * @param[in]  a  pointer to the first input tensor A
343  * @param[in]  na pointer to the extents of input tensor A
344  * @param[in]  wa pointer to the strides of input tensor A
345  * @param[in]  b  pointer to the second input tensor B
346 */
347 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
mtv(SizeType const m,PointerOut c,SizeType const * const,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b)348 void mtv(SizeType const m,
349          PointerOut c, SizeType const*const   , SizeType const*const wc,
350          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
351          PointerIn2 b)
352 {
353 	// decides whether matrix multiplied with vector or vector multiplied with matrix
354 	const auto o = (m == 0) ? 1 : 0;
355 
356 	for(auto io = 0u; io < na[o]; c += wc[o], a += wa[o], ++io) {
357 		auto c1 = c; auto a1 = a; auto b1 = b;
358 		for(auto im = 0u; im < na[m]; a1 += wa[m], ++b1, ++im)
359 			*c1 += *a1 * *b1;
360 	}
361 }
362 
363 
364 /** @brief Computes the matrix-times-matrix product
365  *
366  * Implements C[i1,i3] = sum(A[i1,i2] * B[i2,i3])
367  *
368  * @note is used in function ttm
369  *
370  * @param[out] c  pointer to the output tensor C
371  * @param[in]  nc pointer to the extents of tensor C
372  * @param[in]  wc pointer to the strides of tensor C
373  * @param[in]  a  pointer to the first input tensor A
374  * @param[in]  na pointer to the extents of input tensor A
375  * @param[in]  wa pointer to the strides of input tensor A
376  * @param[in]  b  pointer to the second input tensor B
377  * @param[in]  nb pointer to the extents of input tensor B
378  * @param[in]  wb pointer to the strides of input tensor B
379 */
380 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
mtm(PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)381 void mtm(PointerOut c, SizeType const*const nc, SizeType const*const wc,
382          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
383          PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
384 {
385 
386 	// C(i,j) = A(i,k) * B(k,j)
387 
388 	assert(nc[0] == na[0]);
389 	assert(nc[1] == nb[1]);
390 	assert(na[1] == nb[0]);
391 
392 	auto cj = c; auto bj = b;
393 	for(auto j = 0u; j < nc[1]; cj += wc[1], bj += wb[1], ++j) {
394 
395 		auto bk = bj; auto ak = a;
396 		for(auto k = 0u; k < na[1]; ak += wa[1], bk += wb[0], ++k) {
397 
398 			auto ci = cj; auto ai = ak;
399 			for(auto i = 0u; i < na[0]; ai += wa[0], ci += wc[0], ++i){
400 				*ci += *ai * *bk;
401 			}
402 
403 		}
404 
405 	}
406 }
407 
408 
409 
410 /** @brief Computes the inner product of two tensors
411  *
412  * Implements c = sum(A[i1,i2,...,ip] * B[i1,i2,...,ip])
413  *
414  * @note is used in function inner
415  *
416  * @param r   zero-based recursion level starting with p-1
417  * @param n   pointer to the extents of input or output tensor
418  * @param a   pointer to the first input tensor
419  * @param wa  pointer to the strides of input tensor a
420  * @param b   pointer to the second input tensor
421  * @param wb  pointer to the strides of tensor b
422  * @param v   previously computed value (start with v = 0).
423  * @return    inner product of two tensors.
424 */
425 template <class PointerIn1, class PointerIn2, class value_t, class SizeType>
inner(SizeType const r,SizeType const * const n,PointerIn1 a,SizeType const * const wa,PointerIn2 b,SizeType const * const wb,value_t v)426 value_t inner(SizeType const r, SizeType const*const n,
427               PointerIn1  a, SizeType const*const wa,
428               PointerIn2  b, SizeType const*const wb,
429               value_t v)
430 {
431 	if(r == 0)
432 		for(auto i0 = 0u; i0 < n[0]; a += wa[0], b += wb[0], ++i0)
433 			v += *a * *b;
434 	else
435 		for(auto ir = 0u; ir < n[r]; a += wa[r], b += wb[r], ++ir)
436 			v = inner(r-1, n,   a, wa,    b, wb, v);
437 	return v;
438 }
439 
440 
441 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
outer_2x2(SizeType const pa,PointerOut c,SizeType const * const,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)442 void outer_2x2(SizeType const pa,
443                PointerOut c, SizeType const*const   , SizeType const*const wc,
444                PointerIn1 a, SizeType const*const na, SizeType const*const wa,
445                PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
446 {
447 	//	assert(rc == 3);
448 	//	assert(ra == 1);
449 	//	assert(rb == 1);
450 
451 	for(auto ib1 = 0u; ib1 < nb[1]; b += wb[1], c += wc[pa+1], ++ib1) {
452 		auto c2 = c;
453 		auto b0 = b;
454 		for(auto ib0 = 0u; ib0 < nb[0]; b0 += wb[0], c2 += wc[pa], ++ib0) {
455 			const auto b = *b0;
456 			auto c1 = c2;
457 			auto a1 = a;
458 			for(auto ia1 = 0u; ia1 < na[1]; a1 += wa[1], c1 += wc[1], ++ia1) {
459 				auto a0 = a1;
460 				auto c0 = c1;
461 				for(SizeType ia0 = 0u; ia0 < na[0]; a0 += wa[0], c0 += wc[0], ++ia0)
462 					*c0 = *a0 * b;
463 			}
464 		}
465 	}
466 }
467 
468 /** @brief Computes the outer product of two tensors
469  *
470  * Implements C[i1,...,ip,j1,...,jq] = A[i1,i2,...,ip] * B[j1,j2,...,jq]
471  *
472  * @note called by outer
473  *
474  *
475  * @param[in]  pa number of dimensions (rank) of the first input tensor A with pa > 0
476  *
477  * @param[in]  rc recursion level for C that starts with pc-1
478  * @param[out] c  pointer to the output tensor
479  * @param[in]  nc pointer to the extents of output tensor c
480  * @param[in]  wc pointer to the strides of output tensor c
481  *
482  * @param[in]  ra recursion level for A that starts with pa-1
483  * @param[in]  a  pointer to the first input tensor
484  * @param[in]  na pointer to the extents of the first input tensor a
485  * @param[in]  wa pointer to the strides of the first input tensor a
486  *
487  * @param[in]  rb recursion level for B that starts with pb-1
488  * @param[in]  b  pointer to the second input tensor
489  * @param[in]  nb pointer to the extents of the second input tensor b
490  * @param[in]  wb pointer to the strides of the second input tensor b
491 */
492 template<class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
outer(SizeType const pa,SizeType const rc,PointerOut c,SizeType const * const nc,SizeType const * const wc,SizeType const ra,PointerIn1 a,SizeType const * const na,SizeType const * const wa,SizeType const rb,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)493 void outer(SizeType const pa,
494            SizeType const rc, PointerOut c, SizeType const*const nc, SizeType const*const wc,
495            SizeType const ra, PointerIn1 a, SizeType const*const na, SizeType const*const wa,
496            SizeType const rb, PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
497 {
498 	if(rb > 1)
499 		for(auto ib = 0u; ib < nb[rb]; b += wb[rb], c += wc[rc], ++ib)
500 			outer(pa, rc-1, c, nc, wc,    ra, a, na, wa,    rb-1, b, nb, wb);
501 	else if(ra > 1)
502 		for(auto ia = 0u; ia < na[ra]; a += wa[ra], c += wc[ra], ++ia)
503 			outer(pa, rc-1, c, nc, wc,   ra-1, a, na, wa,   rb, b, nb, wb);
504 	else
505 		outer_2x2(pa, c, nc, wc,   a, na, wa,    b, nb, wb); //assert(ra==1 && rb==1 && rc==3);
506 }
507 
508 
509 
510 
511 /** @brief Computes the outer product with permutation tuples
512  *
513  * Implements C[i1,...,ir,j1,...,js] = sum( A[i1,...,ir] * B[j1,...,js]  )
514  *
515  * nc[x]         = na[phia[x]] for 1 <= x <= r
516  * nc[r+x]       = nb[phib[x]] for 1 <= x <= s
517  *
518  * @note maybe called by ttt function
519  *
520  * @param k  zero-based recursion level starting with 0
521  * @param r  number of non-contraction indices of A
522  * @param s  number of non-contraction indices of B
523  * @param phia pointer to the permutation tuple of length r for A
524  * @param phib pointer to the permutation tuple of length s for B
525  * @param c  pointer to the output tensor C with rank(A)=r+s
526  * @param nc pointer to the extents of tensor C
527  * @param wc pointer to the strides of tensor C
528  * @param a  pointer to the first input tensor with rank(A)=r
529  * @param na pointer to the extents of the first input tensor A
530  * @param wa pointer to the strides of the first input tensor A
531  * @param b  pointer to the second input tensor B with rank(B)=s
532  * @param nb pointer to the extents of the second input tensor B
533  * @param wb pointer to the strides of the second input tensor B
534 */
535 
536 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
outer(SizeType const k,SizeType const r,SizeType const s,SizeType const * const phia,SizeType const * const phib,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)537 void outer(SizeType const k,
538            SizeType const r, SizeType const s,
539            SizeType const*const phia, SizeType const*const phib,
540            PointerOut c, SizeType const*const nc, SizeType const*const wc,
541            PointerIn1 a, SizeType const*const na, SizeType const*const wa,
542            PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
543 {
544 	if(k < r)
545 	{
546 		assert(nc[k] == na[phia[k]-1]);
547 		for(size_t ic = 0u; ic < nc[k]; a += wa[phia[k]-1], c += wc[k], ++ic)
548 			outer(k+1, r, s,   phia,phib,  c, nc, wc,   a, na, wa,   b, nb, wb);
549 	}
550 	else if(k < r+s-1)
551 	{
552 		assert(nc[k] == nb[phib[k-r]-1]);
553 		for(size_t ic = 0u; ic < nc[k]; b += wb[phib[k-r]-1], c += wc[k], ++ic)
554 			outer(k+1, r, s, phia, phib,    c, nc, wc,   a, na, wa,   b, nb, wb);
555 	}
556 	else
557 	{
558 		assert(nc[k] == nb[phib[k-r]-1]);
559 		for(size_t ic = 0u; ic < nc[k]; b += wb[phib[k-r]-1], c += wc[k], ++ic)
560 			*c = *a * *b;
561 	}
562 }
563 
564 
565 } // namespace recursive
566 } // namespace detail
567 } // namespace ublas
568 } // namespace numeric
569 } // namespace boost
570 
571 
572 
573 
574 //////////////////////////////////////////////////////////////////////////////////////////
575 //////////////////////////////////////////////////////////////////////////////////////////
576 //////////////////////////////////////////////////////////////////////////////////////////
577 //////////////////////////////////////////////////////////////////////////////////////////
578 
579 //////////////////////////////////////////////////////////////////////////////////////////
580 //////////////////////////////////////////////////////////////////////////////////////////
581 //////////////////////////////////////////////////////////////////////////////////////////
582 //////////////////////////////////////////////////////////////////////////////////////////
583 
584 
585 #include <stdexcept>
586 
587 namespace boost {
588 namespace numeric {
589 namespace ublas {
590 
591 /** @brief Computes the tensor-times-vector product
592  *
593  * Implements
594  *   C[i1,i2,...,im-1,im+1,...,ip] = sum(A[i1,i2,...,im,...,ip] * b[im]) for m>1 and
595  *   C[i2,...,ip]                  = sum(A[i1,...,ip]           * b[i1]) for m=1
596  *
597  * @note calls detail::ttv, detail::ttv0 or detail::mtv
598  *
599  * @param[in]  m  contraction mode with 0 < m <= p
600  * @param[in]  p  number of dimensions (rank) of the first input tensor with p > 0
601  * @param[out] c  pointer to the output tensor with rank p-1
602  * @param[in]  nc pointer to the extents of tensor c
603  * @param[in]  wc pointer to the strides of tensor c
604  * @param[in]  a  pointer to the first input tensor
605  * @param[in]  na pointer to the extents of input tensor a
606  * @param[in]  wa pointer to the strides of input tensor a
607  * @param[in]  b  pointer to the second input tensor
608  * @param[in]  nb pointer to the extents of input tensor b
609  * @param[in]  wb pointer to the strides of input tensor b
610 */
611 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
ttv(SizeType const m,SizeType const p,PointerOut c,SizeType const * const nc,SizeType const * const wc,const PointerIn1 a,SizeType const * const na,SizeType const * const wa,const PointerIn2 b,SizeType const * const nb,SizeType const * const wb)612 void ttv(SizeType const m, SizeType const p,
613          PointerOut c,       SizeType const*const nc, SizeType const*const wc,
614          const PointerIn1 a, SizeType const*const na, SizeType const*const wa,
615          const PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
616 {
617 	static_assert( std::is_pointer<PointerOut>::value & std::is_pointer<PointerIn1>::value & std::is_pointer<PointerIn2>::value,
618 	               "Static error in boost::numeric::ublas::ttv: Argument types for pointers are not pointer types.");
619 
620 	if( m == 0)
621 		throw std::length_error("Error in boost::numeric::ublas::ttv: Contraction mode must be greater than zero.");
622 
623 	if( p < m )
624 		throw std::length_error("Error in boost::numeric::ublas::ttv: Rank must be greater equal the modus.");
625 
626 	if( p == 0)
627 		throw std::length_error("Error in boost::numeric::ublas::ttv: Rank must be greater than zero.");
628 
629 	if(c == nullptr || a == nullptr || b == nullptr)
630 		throw std::length_error("Error in boost::numeric::ublas::ttv: Pointers shall not be null pointers.");
631 
632 	for(auto i = 0u; i < m-1; ++i)
633 		if(na[i] != nc[i])
634 			throw std::length_error("Error in boost::numeric::ublas::ttv: Extents (except of dimension mode) of A and C must be equal.");
635 
636 	for(auto i = m; i < p; ++i)
637 		if(na[i] != nc[i-1])
638 			throw std::length_error("Error in boost::numeric::ublas::ttv: Extents (except of dimension mode) of A and C must be equal.");
639 
640 	const auto max = std::max(nb[0], nb[1]);
641 	if(  na[m-1] != max)
642 		throw std::length_error("Error in boost::numeric::ublas::ttv: Extent of dimension mode of A and b must be equal.");
643 
644 
645 	if((m != 1) && (p > 2))
646 		detail::recursive::ttv(m-1, p-1, p-2, c, nc, wc,    a, na, wa,   b);
647 	else if ((m == 1) && (p > 2))
648 		detail::recursive::ttv0(p-1, c, nc, wc,  a, na, wa,   b);
649 	else if( p == 2 )
650 		detail::recursive::mtv(m-1, c, nc, wc,  a, na, wa,   b);
651 	else /*if( p == 1 )*/{
652 		auto v = std::remove_pointer_t<std::remove_cv_t<PointerOut>>{};
653 		*c = detail::recursive::inner(SizeType(0), na, a, wa, b, wb, v);
654 	}
655 
656 }
657 
658 
659 
660 /** @brief Computes the tensor-times-matrix product
661  *
662  * Implements
663  *   C[i1,i2,...,im-1,j,im+1,...,ip] = sum(A[i1,i2,...,im,...,ip] * B[j,im]) for m>1 and
664  *   C[j,i2,...,ip]                  = sum(A[i1,i2,...,ip]        * B[j,i1]) for m=1
665  *
666  * @note calls detail::ttm or detail::ttm0
667  *
668  * @param[in]  m  contraction mode with 0 < m <= p
669  * @param[in]  p  number of dimensions (rank) of the first input tensor with p > 0
670  * @param[out] c  pointer to the output tensor with rank p-1
671  * @param[in]  nc pointer to the extents of tensor c
672  * @param[in]  wc pointer to the strides of tensor c
673  * @param[in]  a  pointer to the first input tensor
674  * @param[in]  na pointer to the extents of input tensor a
675  * @param[in]  wa pointer to the strides of input tensor a
676  * @param[in]  b  pointer to the second input tensor
677  * @param[in]  nb pointer to the extents of input tensor b
678  * @param[in]  wb pointer to the strides of input tensor b
679 */
680 
681 template <class PointerIn1, class PointerIn2, class PointerOut, class SizeType>
ttm(SizeType const m,SizeType const p,PointerOut c,SizeType const * const nc,SizeType const * const wc,const PointerIn1 a,SizeType const * const na,SizeType const * const wa,const PointerIn2 b,SizeType const * const nb,SizeType const * const wb)682 void ttm(SizeType const m, SizeType const p,
683          PointerOut c,       SizeType const*const nc, SizeType const*const wc,
684          const PointerIn1 a, SizeType const*const na, SizeType const*const wa,
685          const PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
686 {
687 
688 	static_assert( std::is_pointer<PointerOut>::value & std::is_pointer<PointerIn1>::value & std::is_pointer<PointerIn2>::value,
689 	               "Static error in boost::numeric::ublas::ttm: Argument types for pointers are not pointer types.");
690 
691 	if( m == 0 )
692 		throw std::length_error("Error in boost::numeric::ublas::ttm: Contraction mode must be greater than zero.");
693 
694 	if( p < m )
695 		throw std::length_error("Error in boost::numeric::ublas::ttm: Rank must be greater equal than the specified mode.");
696 
697 	if( p == 0)
698 		throw std::length_error("Error in boost::numeric::ublas::ttm:Rank must be greater than zero.");
699 
700 	if(c == nullptr || a == nullptr || b == nullptr)
701 		throw std::length_error("Error in boost::numeric::ublas::ttm: Pointers shall not be null pointers.");
702 
703 	for(auto i = 0u; i < m-1; ++i)
704 		if(na[i] != nc[i])
705 			throw std::length_error("Error in boost::numeric::ublas::ttm: Extents (except of dimension mode) of A and C must be equal.");
706 
707 	for(auto i = m; i < p; ++i)
708 		if(na[i] != nc[i])
709 			throw std::length_error("Error in boost::numeric::ublas::ttm: Extents (except of dimension mode) of A and C must be equal.");
710 
711 	if(na[m-1] != nb[1])
712 		throw std::length_error("Error in boost::numeric::ublas::ttm: 2nd Extent of B and M-th Extent of A must be the equal.");
713 
714 	if(nc[m-1] != nb[0])
715 		throw std::length_error("Error in boost::numeric::ublas::ttm: 1nd Extent of B and M-th Extent of C must be the equal.");
716 
717 	if ( m != 1 )
718 		detail::recursive::ttm (m-1, p-1, c, nc, wc,    a, na, wa,   b, nb, wb);
719 	else /*if (m == 1 && p >  2)*/
720 		detail::recursive::ttm0(     p-1, c, nc, wc,    a, na, wa,   b, nb, wb);
721 
722 }
723 
724 
725 /** @brief Computes the tensor-times-tensor product
726  *
727  * Implements C[i1,...,ir,j1,...,js] = sum( A[i1,...,ir+q] * B[j1,...,js+q]  )
728  *
729  * @note calls detail::recursive::ttt or ttm or ttv or inner or outer
730  *
731  * nc[x]         = na[phia[x]  ] for 1 <= x <= r
732  * nc[r+x]       = nb[phib[x]  ] for 1 <= x <= s
733  * na[phia[r+x]] = nb[phib[s+x]] for 1 <= x <= q
734  *
735  * @param[in]  pa number of dimensions (rank) of the first input tensor a with pa > 0
736  * @param[in]  pb number of dimensions (rank) of the second input tensor b with pb > 0
737  * @param[in]	 q  number of contraction dimensions with pa >= q and pb >= q and q >= 0
738  * @param[in]	 phia pointer to a permutation tuple for the first input tensor a
739  * @param[in]	 phib pointer to a permutation tuple for the second input tensor b
740  * @param[out] c  pointer to the output tensor with rank p-1
741  * @param[in]  nc pointer to the extents of tensor c
742  * @param[in]  wc pointer to the strides of tensor c
743  * @param[in]  a  pointer to the first input tensor
744  * @param[in]  na pointer to the extents of input tensor a
745  * @param[in]  wa pointer to the strides of input tensor a
746  * @param[in]  b  pointer to the second input tensor
747  * @param[in]  nb pointer to the extents of input tensor b
748  * @param[in]  wb pointer to the strides of input tensor b
749 */
750 
751 template <class PointerIn1, class PointerIn2, class PointerOut, class SizeType>
ttt(SizeType const pa,SizeType const pb,SizeType const q,SizeType const * const phia,SizeType const * const phib,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)752 void ttt(SizeType const pa, SizeType const pb, SizeType const q,
753          SizeType const*const phia, SizeType const*const phib,
754          PointerOut c, SizeType const*const nc, SizeType const*const wc,
755          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
756          PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
757 {
758 	static_assert( std::is_pointer<PointerOut>::value & std::is_pointer<PointerIn1>::value & std::is_pointer<PointerIn2>::value,
759 	               "Static error in boost::numeric::ublas::ttm: Argument types for pointers are not pointer types.");
760 
761 	if( pa == 0 || pb == 0)
762 		throw std::length_error("Error in boost::numeric::ublas::ttt: tensor order must be greater zero.");
763 
764 	if( q > pa && q > pb)
765 		throw std::length_error("Error in boost::numeric::ublas::ttt: number of contraction must be smaller than or equal to the tensor order.");
766 
767 
768 	SizeType const r = pa - q;
769 	SizeType const s = pb - q;
770 
771 	if(c == nullptr || a == nullptr || b == nullptr)
772 		throw std::length_error("Error in boost::numeric::ublas::ttm: Pointers shall not be null pointers.");
773 
774 	for(auto i = 0ul; i < r; ++i)
775 		if( na[phia[i]-1] != nc[i] )
776 			throw std::length_error("Error in boost::numeric::ublas::ttt: dimensions of lhs and res tensor not correct.");
777 
778 	for(auto i = 0ul; i < s; ++i)
779 		if( nb[phib[i]-1] != nc[r+i] )
780 			throw std::length_error("Error in boost::numeric::ublas::ttt: dimensions of rhs and res not correct.");
781 
782 	for(auto i = 0ul; i < q; ++i)
783 		if( nb[phib[s+i]-1] != na[phia[r+i]-1] )
784 			throw std::length_error("Error in boost::numeric::ublas::ttt: dimensions of lhs and rhs not correct.");
785 
786 
787 	if(q == 0ul)
788 		detail::recursive::outer(SizeType{0},r,s,  phia,phib, c,nc,wc, a,na,wa, b,nb,wb);
789 	else
790 		detail::recursive::ttt(SizeType{0},r,s,q,  phia,phib, c,nc,wc, a,na,wa, b,nb,wb);
791 }
792 
793 
794 
795 /** @brief Computes the tensor-times-tensor product
796  *
797  * Implements C[i1,...,ir,j1,...,js] = sum( A[i1,...,ir+q] * B[j1,...,js+q]  )
798  *
799  * @note calls detail::recursive::ttt or ttm or ttv or inner or outer
800  *
801  * nc[x]   = na[x  ] for 1 <= x <= r
802  * nc[r+x] = nb[x  ] for 1 <= x <= s
803  * na[r+x] = nb[s+x] for 1 <= x <= q
804  *
805  * @param[in]  pa number of dimensions (rank) of the first input tensor a with pa > 0
806  * @param[in]  pb number of dimensions (rank) of the second input tensor b with pb > 0
807  * @param[in]	 q  number of contraction dimensions with pa >= q and pb >= q and q >= 0
808  * @param[out] c  pointer to the output tensor with rank p-1
809  * @param[in]  nc pointer to the extents of tensor c
810  * @param[in]  wc pointer to the strides of tensor c
811  * @param[in]  a  pointer to the first input tensor
812  * @param[in]  na pointer to the extents of input tensor a
813  * @param[in]  wa pointer to the strides of input tensor a
814  * @param[in]  b  pointer to the second input tensor
815  * @param[in]  nb pointer to the extents of input tensor b
816  * @param[in]  wb pointer to the strides of input tensor b
817 */
818 
819 template <class PointerIn1, class PointerIn2, class PointerOut, class SizeType>
ttt(SizeType const pa,SizeType const pb,SizeType const q,PointerOut c,SizeType const * const nc,SizeType const * const wc,PointerIn1 a,SizeType const * const na,SizeType const * const wa,PointerIn2 b,SizeType const * const nb,SizeType const * const wb)820 void ttt(SizeType const pa, SizeType const pb, SizeType const q,
821          PointerOut c, SizeType const*const nc, SizeType const*const wc,
822          PointerIn1 a, SizeType const*const na, SizeType const*const wa,
823          PointerIn2 b, SizeType const*const nb, SizeType const*const wb)
824 {
825 	static_assert( std::is_pointer<PointerOut>::value & std::is_pointer<PointerIn1>::value & std::is_pointer<PointerIn2>::value,
826 	               "Static error in boost::numeric::ublas::ttm: Argument types for pointers are not pointer types.");
827 
828 	if( pa == 0 || pb == 0)
829 		throw std::length_error("Error in boost::numeric::ublas::ttt: tensor order must be greater zero.");
830 
831 	if( q > pa && q > pb)
832 		throw std::length_error("Error in boost::numeric::ublas::ttt: number of contraction must be smaller than or equal to the tensor order.");
833 
834 
835 	SizeType const r  = pa - q;
836 	SizeType const s  = pb - q;
837 	SizeType const pc = r+s;
838 
839 	if(c == nullptr || a == nullptr || b == nullptr)
840 		throw std::length_error("Error in boost::numeric::ublas::ttm: Pointers shall not be null pointers.");
841 
842 	for(auto i = 0ul; i < r; ++i)
843 		if( na[i] != nc[i] )
844 			throw std::length_error("Error in boost::numeric::ublas::ttt: dimensions of lhs and res tensor not correct.");
845 
846 	for(auto i = 0ul; i < s; ++i)
847 		if( nb[i] != nc[r+i] )
848 			throw std::length_error("Error in boost::numeric::ublas::ttt: dimensions of rhs and res not correct.");
849 
850 	for(auto i = 0ul; i < q; ++i)
851 		if( nb[s+i] != na[r+i] )
852 			throw std::length_error("Error in boost::numeric::ublas::ttt: dimensions of lhs and rhs not correct.");
853 
854 	using value_type = std::decay_t<decltype(*c)>;
855 
856 
857 
858 	if(q == 0ul)
859 		detail::recursive::outer(pa, pc-1, c,nc,wc, pa-1, a,na,wa, pb-1, b,nb,wb);
860 	else if(r == 0ul && s == 0ul)
861 		*c = detail::recursive::inner(q-1, na, a,wa,  b,wb, value_type(0) );
862 	else
863 		detail::recursive::ttt(SizeType{0},r,s,q, c,nc,wc, a,na,wa, b,nb,wb);
864 }
865 
866 
867 /** @brief Computes the inner product of two tensors
868  *
869  * Implements c = sum(A[i1,i2,...,ip] * B[i1,i2,...,ip])
870  *
871  * @note calls detail::inner
872  *
873  * @param[in] p  number of dimensions (rank) of the first input tensor with p > 0
874  * @param[in] n  pointer to the extents of input or output tensor
875  * @param[in] a  pointer to the first input tensor
876  * @param[in] wa pointer to the strides of input tensor a
877  * @param[in] b  pointer to the second input tensor
878  * @param[in] wb pointer to the strides of input tensor b
879  * @param[in] v  inital value
880  *
881  * @return   inner product of two tensors.
882 */
883 template <class PointerIn1, class PointerIn2, class value_t, class SizeType>
inner(const SizeType p,SizeType const * const n,const PointerIn1 a,SizeType const * const wa,const PointerIn2 b,SizeType const * const wb,value_t v)884 auto inner(const SizeType    p, SizeType const*const n,
885            const PointerIn1  a, SizeType const*const wa,
886            const PointerIn2  b, SizeType const*const wb,
887            value_t v)
888 {
889 	static_assert( std::is_pointer<PointerIn1>::value && std::is_pointer<PointerIn2>::value,
890 	               "Static error in boost::numeric::ublas::inner: Argument types for pointers must be pointer types.");
891 	if(p<2)
892 		throw std::length_error("Error in boost::numeric::ublas::inner: Rank must be greater than zero.");
893 	if(a == nullptr || b == nullptr)
894 		throw std::length_error("Error in boost::numeric::ublas::inner: Pointers shall not be null pointers.");
895 
896 	return detail::recursive::inner(p-1, n, a, wa, b, wb, v);
897 
898 }
899 
900 
901 /** @brief Computes the outer product of two tensors
902  *
903  * Implements C[i1,...,ip,j1,...,jq] = A[i1,i2,...,ip] * B[j1,j2,...,jq]
904  *
905  * @note calls detail::outer
906  *
907  * @param[out] c  pointer to the output tensor
908  * @param[in]  pc number of dimensions (rank) of the output tensor c with pc > 0
909  * @param[in]  nc pointer to the extents of output tensor c
910  * @param[in]  wc pointer to the strides of output tensor c
911  * @param[in]  a  pointer to the first input tensor
912  * @param[in]  pa number of dimensions (rank) of the first input tensor a with pa > 0
913  * @param[in]  na pointer to the extents of the first input tensor a
914  * @param[in]  wa pointer to the strides of the first input tensor a
915  * @param[in]  b  pointer to the second input tensor
916  * @param[in]  pb number of dimensions (rank) of the second input tensor b with pb > 0
917  * @param[in]  nb pointer to the extents of the second input tensor b
918  * @param[in]  wb pointer to the strides of the second input tensor b
919 */
920 template <class PointerOut, class PointerIn1, class PointerIn2, class SizeType>
outer(PointerOut c,SizeType const pc,SizeType const * const nc,SizeType const * const wc,const PointerIn1 a,SizeType const pa,SizeType const * const na,SizeType const * const wa,const PointerIn2 b,SizeType const pb,SizeType const * const nb,SizeType const * const wb)921 void outer(PointerOut c,       SizeType const pc, SizeType const*const nc, SizeType const*const wc,
922            const PointerIn1 a, SizeType const pa, SizeType const*const na, SizeType const*const wa,
923            const PointerIn2 b, SizeType const pb, SizeType const*const nb, SizeType const*const wb)
924 {
925 	static_assert( std::is_pointer<PointerIn1>::value & std::is_pointer<PointerIn2>::value & std::is_pointer<PointerOut>::value,
926 	               "Static error in boost::numeric::ublas::outer: argument types for pointers must be pointer types.");
927 	if(pa < 2u || pb < 2u)
928 		throw std::length_error("Error in boost::numeric::ublas::outer: number of extents of lhs and rhs tensor must be equal or greater than two.");
929 	if((pa + pb) != pc)
930 		throw std::length_error("Error in boost::numeric::ublas::outer: number of extents of lhs plus rhs tensor must be equal to the number of extents of C.");
931 	if(a == nullptr || b == nullptr || c == nullptr)
932 		throw std::length_error("Error in boost::numeric::ublas::outer: pointers shall not be null pointers.");
933 
934 	detail::recursive::outer(pa, pc-1, c, nc, wc,   pa-1, a, na, wa,   pb-1, b, nb, wb);
935 
936 }
937 
938 
939 
940 
941 }
942 }
943 }
944 
945 #endif
946