refs #11056. Fix exposing peak to python.

Keep changes to setQLabFrame as expoesed to python instep with what's changed on the c++ side and test it.

Code/Mantid/Framework/DataObjects/test/PeakTest.h

@@ -346,25 +346,14 @@ public:
 
       V3D qLab = qLabDir * wavenumber_in_angstrom_times_tof_in_microsec;
 
-
-      //Peak peak(minimalInstrument, 1 /* detector id */, x[0] /*wavelength*/);
-
-
-
       Peak peak; // Everything will be default
       peak.setInstrument(minimalInstrument); // Can't do anything without the instrument
       peak.setQLabFrame(qLab);
       auto detector = peak.getDetector();
 
       TSM_ASSERT("No detector", detector);
-      if(detector)
-      {
-          TS_ASSERT_EQUALS(1, detector->getID());
-          TS_ASSERT_EQUALS(detectorPos, detector->getPos());
-      }
-
-      // Test that wavelengths aggree firstly.
-      //TS_ASSERT_EQUALS(x[0], peak.getWavelength());
+      TS_ASSERT_EQUALS(1, detector->getID());
+      TS_ASSERT_EQUALS(detectorPos, detector->getPos());
   }
 
   /** Create peaks using Q in sample frame + a goniometer rotation matrix*/

Code/Mantid/Framework/PythonInterface/mantid/api/src/Exports/IPeak.cpp

@@ -6,9 +6,13 @@ using Mantid::API::IPeak;
 using namespace boost::python;
 
 namespace {
-Mantid::Geometry::PeakShape_sptr getPeakShape(IPeak& peak) {
-    // Use clone to make a copy of the PeakShape.
-    return Mantid::Geometry::PeakShape_sptr(peak.getPeakShape().clone());
+Mantid::Geometry::PeakShape_sptr getPeakShape(IPeak &peak) {
+  // Use clone to make a copy of the PeakShape.
+  return Mantid::Geometry::PeakShape_sptr(peak.getPeakShape().clone());
+}
+void setQLabFrame(IPeak &peak, Mantid::Kernel::V3D qLabFrame, double distance) {
+  // Set the qlab frame
+  return peak.setQLabFrame(qLabFrame, distance);
 }
 }
 
@@ -38,7 +42,8 @@ void export_IPeak()
          "Using the instrument set in the peak, perform ray tracing to find the exact detector.")
     .def("getQSampleFrame", &IPeak::getQSampleFrame, "Return the Q change (of the lattice, k_i - k_f) for this peak."
          "The Q is in the Sample frame: the goniometer rotation WAS taken out. ")
-    .def("setQLabFrame", &IPeak::setQLabFrame, "Set the peak using the peak's position in reciprocal space, in the lab frame.")
+    .def("setQLabFrame", (void (IPeak::*)(Mantid::Kernel::V3D))&IPeak::setQLabFrame)
+    .def("setQLabFrame", setQLabFrame, "Set the peak using the peak's position in reciprocal space, in the lab frame.")
     .def("setQSampleFrame", &IPeak::setQSampleFrame, "Set the peak using the peak's position in reciprocal space, in the sample frame.")
     .def("setWavelength", &IPeak::setWavelength, "Set the incident wavelength of the neutron. Calculates the energy from this assuming elastic scattering.")
     .def("getWavelength", &IPeak::getWavelength, "Return the incident wavelength")

Code/Mantid/Framework/PythonInterface/test/python/mantid/api/IPeaksWorkspaceTest.py

@@ -51,6 +51,22 @@ class IPeaksWorkspaceTest(unittest.TestCase):
         # Peaks workspace will not be integrated by default.
         self.assertTrue(not pws.hasIntegratedPeaks())
 
+    def test_peak_setQLab(self):
+        pws = WorkspaceCreationHelper.createPeaksWorkspace(1)
+        p = pws.getPeak(0)
+        try:
+            p.setQLabFrame(V3D(1,1,1))
+        except Exception:
+            self.fail("Tried setQLabFrame with one V3D argument")
+        
+        try:
+            p.setQLabFrame(V3D(1,1,1), 1)
+        except Exception:
+            self.fail("Tried setQLabFrame with one V3D argument and a double distance")
+        
+        
+
+
 if __name__ == '__main__':
     unittest.main()