Added known failures

MDAnalysis · Aug 1, 2016 · 0f62787 · 0f62787
1 parent 76ec586
commit 0f62787
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Showing 2 changed files with 16 additions and 4 deletions.
diff --git a/package/MDAnalysis/coordinates/src/dcd.c b/package/MDAnalysis/coordinates/src/dcd.c
@@ -535,7 +535,7 @@ __read_timeseries(PyObject *self, PyObject *args)
    for (i=0;i<n_frames;i++) {
       if (step > 1 && i>0) {
          // Check if we have fixed atoms
--        // XXX not done
+         // XXX not done
          /* Figure out how many steps to step over, if step = n, np array
             slicing treats this as skip over n-1, read the nth. */
          numskip = step -1;

diff --git a/testsuite/MDAnalysisTests/coordinates/test_dcd.py b/testsuite/MDAnalysisTests/coordinates/test_dcd.py
@@ -14,7 +14,7 @@
                                                    RefNAMDtriclinicDCD)
 from MDAnalysisTests.coordinates.base import BaseTimestepTest
 from MDAnalysisTests import module_not_found, tempdir
-
+from MDAnalysisTests.plugins.knownfailure import knownfailure
 
 @attr('issue')
 def TestDCD_Issue32():
@@ -137,18 +137,30 @@ def test_volume(self):
 
     def test_timeseries_slicing(self):
         # check that slicing behaves correctly
-        # should fail before issue #914 resolved
+        # should  before issue #914 resolved
         x = [(0, 1, 1), (1,1,1), (1, 2, 1), (1, 2, 2), (1, 4, 2), (1, 4, 4),
-             (0, 5, 5), (3, 5, 1), (5, 0, -2), (5, 0, -1), (None, None, None)]
+             (0, 5, 5), (3, 5, 1), (None, None, None)]
         for start, stop, step in x:
             yield self._slice_generation_test, start, stop, step
 
+    def test_backwards_stepping(self):
+        x = [(4, 0, -1), (5, 0, -2), (5, 0, -4)]
+        for start, stop, step in x:
+            yield self._failed_slices_test, start, stop, step
+
     def _slice_generation_test(self, start, stop, step):
         self.u = mda.Universe(PSF, DCD)
         ts = self.u.trajectory.timeseries(self.u.atoms)
         ts_skip = self.u.trajectory.timeseries(self.u.atoms, start, stop, step)
         assert_array_almost_equal(ts[:, start:stop:step,:], ts_skip, 5)
 
+    @knownfailure()
+    def _failed_slices_test(self, start, stop, step):
+        self.u = mda.Universe(PSF, DCD)
+        ts = self.u.trajectory.timeseries(self.u.atoms)
+        ts_skip = self.u.trajectory.timeseries(self.u.atoms, start, stop, step)
+        assert_array_almost_equal(ts[:, start:stop:step,:], ts_skip, 5)
+
 
 def test_DCDReader_set_dt(dt=100., frame=3):
     u = mda.Universe(PSF, DCD, dt=dt)