BUG: antsRegistration command line failure

The antsRegistration program does not have a
named sampling strategy called "Dense".  In
order to get the 1 sample per voxel sampling
strategy (aka dense sampling) the user must
either not supply anything, or explicitly
supply the "None" name.

Perhaps this should have been called the
"subSamplingStrategy", but that is too
invasive of a change to ants.

Author: hjmjohnson

nipype/interfaces/ants/registration.py

@@ -233,7 +233,7 @@ class RegistrationInputSpec(ANTSCommandInputSpec):
         requires=['metric_weight'],
         desc='the number of bins in each stage for the MI and Mattes metric, '
         'the radius for other metrics')
-    sampling_strategy_item_trait = traits.Enum("Dense", "Regular", "Random", None)
+    sampling_strategy_item_trait = traits.Enum("None", "Regular", "Random", None)
     sampling_strategy_stage_trait = traits.Either(
         sampling_strategy_item_trait, traits.List(sampling_strategy_item_trait))
     sampling_strategy = traits.List(
@@ -390,9 +390,9 @@ class Registration(ANTSCommand):
     >>> reg5.inputs.sampling_strategy = ['Random', None] # use default strategy in second stage
     >>> reg5.inputs.sampling_percentage = [0.05, [0.05, 0.10]]
     >>> reg5.cmdline
-    'antsRegistration --collapse-linear-transforms-to-fixed-image-header 0 --collapse-output-transforms 0 --dimensionality 3 --initial-moving-transform [ trans.mat, 1 ] --interpolation Linear --output [ output_, output_warped_image.nii.gz ] --transform Affine[ 2.0 ] --metric CC[ fixed1.nii, moving1.nii, 1, 4, Random, 0.05 ] --convergence [ 1500x200, 1e-08, 20 ] --smoothing-sigmas 1.0x0.0vox --shrink-factors 2x1 --use-estimate-learning-rate-once 1 --use-histogram-matching 1 --transform SyN[ 0.25, 3.0, 0.0 ] --metric CC[ fixed1.nii, moving1.nii, 0.5, 32, Dense, 0.05 ] --metric Mattes[ fixed1.nii, moving1.nii, 0.5, 32, Dense, 0.1 ] --convergence [ 100x50x30, 1e-09, 20 ] --smoothing-sigmas 2.0x1.0x0.0vox --shrink-factors 3x2x1 --use-estimate-learning-rate-once 1 --use-histogram-matching 1 --winsorize-image-intensities [ 0.0, 1.0 ]  --write-composite-transform 1'
+    'antsRegistration --collapse-linear-transforms-to-fixed-image-header 0 --collapse-output-transforms 0 --dimensionality 3 --initial-moving-transform [ trans.mat, 1 ] --interpolation Linear --output [ output_, output_warped_image.nii.gz ] --transform Affine[ 2.0 ] --metric CC[ fixed1.nii, moving1.nii, 1, 4, Random, 0.05 ] --convergence [ 1500x200, 1e-08, 20 ] --smoothing-sigmas 1.0x0.0vox --shrink-factors 2x1 --use-estimate-learning-rate-once 1 --use-histogram-matching 1 --transform SyN[ 0.25, 3.0, 0.0 ] --metric CC[ fixed1.nii, moving1.nii, 0.5, 32, None, 0.05 ] --metric Mattes[ fixed1.nii, moving1.nii, 0.5, 32, None, 0.1 ] --convergence [ 100x50x30, 1e-09, 20 ] --smoothing-sigmas 2.0x1.0x0.0vox --shrink-factors 3x2x1 --use-estimate-learning-rate-once 1 --use-histogram-matching 1 --winsorize-image-intensities [ 0.0, 1.0 ]  --write-composite-transform 1'
     """
-    DEF_SAMPLING_STRATEGY = 'Dense'
+    DEF_SAMPLING_STRATEGY = 'None'
     """The default sampling stratey argument."""
 
     _cmd = 'antsRegistration'