Add tests for autodiff of operators

[ckolbPTB]

Adds the gradient checks for operators from #307

[github-actions[bot]]

Coverage Report

File	Stmts	Miss	Cover	Missing
src/mrpro/algorithms/csm
inati.py	24	1	96%	44
walsh.py	16	1	94%	34
src/mrpro/algorithms/dcf
dcf_voronoi.py	53	4	92%	15, 48–49, 76
src/mrpro/algorithms/optimizers
adam.py	20	1	95%	69
src/mrpro/algorithms/reconstruction
DirectReconstruction.py	28	16	43%	51–71, 85
IterativeSENSEReconstruction.py	13	1	92%	76
Reconstruction.py	50	22	56%	42, 54–56, 80–87, 104–113
RegularizedIterativeSENSEReconstruction.py	41	17	59%	96–100, 114–139
src/mrpro/data
AcqInfo.py	128	3	98%	26, 169, 207
CsmData.py	29	3	90%	15, 82–84
DcfData.py	45	8	82%	18, 66, 78–83
IData.py	67	9	87%	119, 125, 129, 159–167
IHeader.py	75	7	91%	75, 109, 127–131
KHeader.py	153	17	89%	25, 119–123, 150, 199, 210, 217–218, 221, 228, 260–271
KNoise.py	31	15	52%	39–52, 56–61
KTrajectory.py	69	5	93%	178–182
MoveDataMixin.py	137	18	87%	15, 113, 129, 143–145, 207, 305–307, 320, 399, 419–420, 422, 437–438, 440
QData.py	39	7	82%	42, 65–73
Rotation.py	674	35	95%	100, 198, 335, 433, 477, 495, 581, 583, 592, 626, 628, 691, 768, 773, 776, 791, 808, 813, 889, 1077, 1082, 1085, 1109, 1113, 1240, 1242, 1250–1251, 1315, 1397, 1690, 1846, 1881, 1885, 1996
SpatialDimension.py	230	21	91%	33, 103, 128, 135, 141, 261–263, 276–278, 312, 330, 343, 356, 369, 382, 391–392, 407, 416
acq_filters.py	12	1	92%	47
src/mrpro/data/_kdata
KData.py	134	18	87%	109–110, 125, 132, 142, 150, 204–205, 243, 248–249, 268–279
KDataRemoveOsMixin.py	29	2	93%	44, 46
KDataSelectMixin.py	19	2	89%	48, 63
KDataSplitMixin.py	48	3	94%	53, 84, 93
src/mrpro/data/traj_calculators
KTrajectoryCalculator.py	25	2	92%	23, 45
KTrajectoryIsmrmrd.py	13	2	85%	41, 50
KTrajectoryPulseq.py	29	1	97%	54
src/mrpro/operators
CartesianSamplingOp.py	72	2	97%	118, 157
ConstraintsOp.py	60	2	97%	46, 48
EndomorphOperator.py	65	2	97%	228, 234
FiniteDifferenceOp.py	27	2	93%	40, 105
Functional.py	71	5	93%	20–22, 117, 119
GridSamplingOp.py	136	9	93%	72–73, 82–83, 90–91, 94, 96, 98
LinearOperator.py	171	12	93%	55, 91, 190, 220, 261, 270, 278, 287, 295, 320, 418, 423
LinearOperatorMatrix.py	158	16	90%	82, 119, 152, 161, 166, 175–178, 191–194, 203, 215, 304, 331, 359
MultiIdentityOp.py	13	2	85%	43, 48
Operator.py	78	2	97%	25, 74
ProximableFunctionalSeparableSum.py	39	3	92%	50, 103, 110
SliceProjectionOp.py	173	8	95%	44, 61, 63, 69, 206, 227, 260, 300
WaveletOp.py	120	5	96%	152, 170, 205, 210, 233
ZeroPadOp.py	16	1	94%	30
src/mrpro/utils
filters.py	62	2	97%	44, 49
slice_profiles.py	46	6	87%	20, 36, 113–116, 149
sliding_window.py	34	1	97%	34
split_idx.py	10	2	80%	43, 47
summarize_tensorvalues.py	11	9	18%	20–29
typing.py	18	11	39%	8–23
zero_pad_or_crop.py	31	6	81%	26, 30, 54, 57, 60, 63
TOTAL	4775	350	93%

Tests	Skipped	Failures	Errors	Time
1989	0 :zzz:	0 :x:	0 :fire:	1m 56s :stopwatch:

[ckolbPTB]

The MOLLI test fails. Currently we have: signal(a,b,t1) = a * (1 - b/a * torch.exp(ti / t1 * (1 - b/a)))

The b/a term is what is causing problems. My suggestion would be to change this to signal(a,c,t1) = a * (1 - c * torch.exp(ti / t1 * (1 - c)))

a and b don't have any physiological meaning and this should also make it easier to find good constraints for c.

See #406

[fzimmermann89]

remind me again, we we have no grad_check in the helpers, testing the numeric values of the gradients?

[ckolbPTB]

remind me again, we we have no grad_check in the helpers, testing the numeric values of the gradients?

I don't think we have discussed this yet. If we use pytorch autograd functionality, would this test not merely test pytorch functionality?

[ckolbPTB]

@fzimmermann89 could you have a look at this again please

[github-actions[bot]]

:books: Documentation

:file_folder: Download as zip :mag: View online

[fzimmermann89]

So far, what is there look fine to me

[ckolbPTB]

remind me, what was the plan here? should we add a test for each operator and its adjoint?

With this PR we wanted to add autodiff tests for all non-linear operators. autodiff (and some more) tests for linear operators would then we added in PR #407

[fzimmermann89]

Will need #515 to pass mypy

[fzimmermann89]

Will need #515 to pass mypy

I stand corrected -- #515 would make the type hints more useful, but it passes without the changes