| 1368 | } |
| 1369 | |
| 1370 | shared_ptr<CoefficientFunction> |
| 1371 | EinsumCoefficientFunction::Diff( |
| 1372 | const CoefficientFunction *var, |
| 1373 | shared_ptr<CoefficientFunction> dir) const |
| 1374 | { |
| 1375 | if (this == var) |
| 1376 | return dir; |
| 1377 | |
| 1378 | // IMPORTANT NOTE: |
| 1379 | // use "original_index_signature" and "original_inputs" as only |
| 1380 | // these protect variables etc, i.e. they do not carry any |
| 1381 | // optimization! |
| 1382 | |
| 1383 | auto dres = ZeroCF(Array<int>{Dimensions()}); |
| 1384 | |
| 1385 | for (size_t i: Range(original_inputs.Size())) |
| 1386 | { |
| 1387 | auto new_inputs{original_inputs}; |
| 1388 | new_inputs[i] = original_inputs[i]->Diff(var, dir); |
| 1389 | if (new_inputs[i]->IsZeroCF()) |
| 1390 | continue; |
| 1391 | |
| 1392 | dres = dres + EinsumCF(original_index_signature, new_inputs, options); |
| 1393 | } |
| 1394 | // TODO: great potential for optimization when equivalent objects are |
| 1395 | // identified in Compile |
| 1396 | return dres; |
| 1397 | } |
| 1398 | |
| 1399 | shared_ptr<CoefficientFunction> |
| 1400 | EinsumCoefficientFunction::DiffJacobi( |