TEST: Initial tests for dispfield module

tests/test_transform_dispfield.py

+#!/usr/bin/env python
+
+
+import numpy   as np
+import nibabel as nib
+
+import fsl.data.image                as fslimage
+import fsl.utils.transform           as transform
+import fsl.utils.transform.dispfield as dispfield
+
+
+def _random_field():
+    vx, vy, vz = np.random.randint(10, 50, 3)
+    dx, dy, dz = np.random.randint( 1, 10, 3)
+
+    field = (np.random.random((vx, vy, vz, 3)) - 0.5) * 10
+    aff   = transform.compose(
+        (dx, dy, dz),
+        np.random.randint(1, 100, 3),
+        np.random.random(3) * np.pi / 2)
+
+    return dispfield.DisplacementField(field, xform=aff)
+
+
+def _field_coords(field):
+    vx, vy, vz = field.shape[ :3]
+    coords     = np.meshgrid(np.arange(vx),
+                             np.arange(vy),
+                             np.arange(vz), indexing='ij')
+    coords = np.array(coords).transpose((1, 2, 3, 0))
+    return transform.transform(
+        coords.reshape(-1, 3),
+        field.getAffine('voxel', 'fsl')).reshape(field.shape)
+
+
+def test_detectType():
+    relfield = _random_field()
+    coords   = _field_coords(relfield)
+    absfield = dispfield.DisplacementField(
+        relfield.data + coords, xform=relfield.voxToWorldMat)
+
+    assert dispfield.detectType(relfield) == 'relative'
+    assert dispfield.detectType(absfield) == 'absolute'
+
+
+def test_convertType():
+    relfield = dispfield.DisplacementField(_random_field())
+    coords   = _field_coords(relfield)
+    absfield = fslimage.Image(
+        relfield.data + coords, xform=relfield.voxToWorldMat)
+
+    relfield = dispfield.DisplacementField(relfield)
+    absfield = dispfield.DisplacementField(absfield)
+
+    gotconvrel1 = dispfield.convertType(relfield)
+    gotconvabs1 = dispfield.convertType(absfield)
+    gotconvrel2 = dispfield.convertType(relfield, 'absolute')
+    gotconvabs2 = dispfield.convertType(absfield, 'relative')
+
+    assert np.all(np.isclose(gotconvrel1, absfield.data))
+    assert np.all(np.isclose(gotconvabs1, relfield.data))
+    assert np.all(np.isclose(gotconvrel2, absfield.data))
+    assert np.all(np.isclose(gotconvabs2, relfield.data))