fix problem travis caught, add appropriate unit test

Author: Shoshana Berleant

nipype/algorithms/confounds.py

@@ -339,7 +339,8 @@ def _run_interface(self, runtime):
         # removed [prior to ...]"
         if self.inputs.use_regress_poly:
             voxel_timecourses = regress_poly(self.inputs.regress_poly_degree,
-                                             voxel_timecourses, remove_mean=True)
+                                             voxel_timecourses)
+        voxel_timecourses = regress_poly(0, voxel_timecourses, remove_mean=True)
 
         # "Voxel time series from the noise ROI (either anatomical or tSTD) were
         # placed in a matrix M of size Nxm, with time along the row dimension

nipype/algorithms/tests/test_compcor.py

@@ -66,6 +66,14 @@ def test_tcompcor_no_percentile(self):
         num_nonmasked_voxels = np.count_nonzero(mask)
         assert_equal(num_nonmasked_voxels, 1)
 
+    def test_compcor_no_regress_poly(self):
+        self.run_cc(CompCor(realigned_file=self.realigned_file, mask_file=self.mask_file,
+                            use_regress_poly=False), [['0.4451946442', '-0.7683311482'],
+                                                      ['-0.4285129505', '-0.0926034137'],
+                                                      ['0.5721540256', '0.5608764842'],
+                                                      ['-0.5367548139', '0.0059943226'],
+                                                      ['-0.0520809054', '0.2940637551']])
+
     def run_cc(self, ccinterface, expected_components):
         # run
         ccresult = ccinterface.run()