Merge pull request #4440 from jzuhone/offaxis_particle

doc/source/visualizing/FITSImageData.ipynb

@@ -133,10 +133,7 @@
   {
    "cell_type": "markdown",
    "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%% md\n"
-    }
+    "collapsed": false
    },
    "source": [
     "## Making FITS images from Particle Projections"
@@ -149,10 +146,7 @@
     "`FITSParticleProjection`:"
    ],
    "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%% md\n"
-    }
+    "collapsed": false
    }
   },
   {
@@ -167,10 +161,7 @@
     "prjp_fits.writeto(\"prjp.fits\", overwrite=True)"
    ],
    "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
+    "collapsed": false
    }
   },
   {
@@ -183,10 +174,7 @@
     "for example), supply the ``density`` keyword argument:"
    ],
    "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%% md\n"
-    }
+    "collapsed": false
    }
   },
   {
@@ -200,10 +188,32 @@
     "prjpd_fits.writeto(\"prjpd.fits\", overwrite=True)"
    ],
    "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
+    "collapsed": false
+   }
+  },
+  {
+   "cell_type": "markdown",
+   "source": [
+    "`FITSParticleOffAxisProjection` can be used to make a projection along any arbitrary sight line:"
+   ],
+   "metadata": {
+    "collapsed": false
+   }
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "outputs": [],
+   "source": [
+    "L = [1, -1, 1]  # normal or \"line of sight\" vector\n",
+    "N = [0, 0, 1]  # north or \"up\" vector\n",
+    "poff_fits = yt.FITSParticleOffAxisProjection(\n",
+    "    dsp, L, (\"PartType1\", \"particle_mass\"), deposition=\"cic\", north_vector=N\n",
+    ")\n",
+    "poff_fits.writeto(\"poff.fits\", overwrite=True)"
+   ],
+   "metadata": {
+    "collapsed": false
    }
   },
   {
@@ -212,10 +222,7 @@
     "## Using `HDUList` Methods"
    ],
    "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%% md\n"
-    }
+    "collapsed": false
    }
   },
   {

doc/source/visualizing/plots.rst

@@ -2027,7 +2027,25 @@ domain:
    p.set_unit(("all", "particle_mass"), "Msun")
    p.save()
 
-and here is an example of using the ``data_source`` argument to :class:`~yt.visualization.particle_plots.ParticlePhasePlot`
+Using :class:`~yt.visualization.particle_plots.ParticleProjectionPlot`, you can also plot particles
+along an off-axis direction:
+
+.. python-script::
+
+   import yt
+
+   ds = yt.load("IsolatedGalaxy/galaxy0030/galaxy0030")
+
+   L = [1, 1, 1] # normal or "line of sight" vector
+   N = [0, 1, 0] # north or "up" vector
+
+    p = yt.ParticleProjectionPlot(
+        ds, L, [("all", "particle_mass")], width=(0.05, 0.05), depth=0.3, north_vector=N
+    )
+   p.set_unit(("all", "particle_mass"), "Msun")
+   p.save()
+
+Here is an example of using the ``data_source`` argument to :class:`~yt.visualization.particle_plots.ParticlePhasePlot`
 to only consider the particles that lie within a 50 kpc sphere around the domain center:
 
 .. python-script::

tests/tests.yaml

@@ -102,9 +102,10 @@ answer_tests:
     - yt/frontends/owls/tests/test_outputs.py:test_snapshot_033
     - yt/frontends/owls/tests/test_outputs.py:test_OWLS_particlefilter
 
-  local_pw_048:  # PR 4417
+  local_pw_049:  # PR 4440
     - yt/visualization/tests/test_plotwindow.py:test_attributes
     - yt/visualization/tests/test_particle_plot.py:test_particle_projection_answers
+    - yt/visualization/tests/test_particle_plot.py:test_particle_offaxis_projection_answers
     - yt/visualization/tests/test_particle_plot.py:test_particle_projection_filter
     - yt/visualization/tests/test_particle_plot.py:test_particle_phase_answers
     - yt/visualization/tests/test_callbacks.py:test_axis_manipulations

yt/__init__.py

@@ -118,6 +118,7 @@ def run_nose(*args, **kwargs):
     FITSImageData,
     FITSOffAxisProjection,
     FITSOffAxisSlice,
+    FITSParticleOffAxisProjection,
     FITSParticleProjection,
     FITSProjection,
     FITSSlice,

yt/utilities/lib/pixelization_routines.pyx

@@ -1781,24 +1781,13 @@ def pixelize_element_mesh_line(np.ndarray[np.float64_t, ndim=2] coords,
 
 @cython.boundscheck(False)
 @cython.wraparound(False)
-def off_axis_projection_SPH(np.float64_t[:] px,
-                            np.float64_t[:] py,
-                            np.float64_t[:] pz,
-                            np.float64_t[:] particle_masses,
-                            np.float64_t[:] particle_densities,
-                            np.float64_t[:] smoothing_lengths,
-                            bounds,
-                            center,
-                            width,
-                            np.float64_t[:] quantity_to_smooth,
-                            np.float64_t[:, :] projection_array,
-                            normal_vector,
-                            north_vector,
-                            weight_field=None):
-    # Do nothing in event of a 0 normal vector
-    if np.allclose(normal_vector, np.array([0., 0., 0.]), rtol=1e-09):
-        return
-
+def rotate_particle_coord(np.float64_t[:] px,
+                          np.float64_t[:] py,
+                          np.float64_t[:] pz,
+                          center,
+                          width,
+                          normal_vector,
+                          north_vector):
     # We want to do two rotations, one to first rotate our coordinates to have
     # the normal vector be the z-axis (i.e., the viewer's perspective), and then
     # another rotation to make the north-vector be the y-axis (i.e., north).
@@ -1839,6 +1828,34 @@ def off_axis_projection_SPH(np.float64_t[:] px,
         px_rotated[i] = rotated_coordinates[0]
         py_rotated[i] = rotated_coordinates[1]
 
+    return px_rotated, py_rotated, rot_bounds_x0, rot_bounds_x1, rot_bounds_y0, rot_bounds_y1
+
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+def off_axis_projection_SPH(np.float64_t[:] px,
+                            np.float64_t[:] py,
+                            np.float64_t[:] pz,
+                            np.float64_t[:] particle_masses,
+                            np.float64_t[:] particle_densities,
+                            np.float64_t[:] smoothing_lengths,
+                            bounds,
+                            center,
+                            width,
+                            np.float64_t[:] quantity_to_smooth,
+                            np.float64_t[:, :] projection_array,
+                            normal_vector,
+                            north_vector,
+                            weight_field=None):
+    # Do nothing in event of a 0 normal vector
+    if np.allclose(normal_vector, 0.):
+        return
+
+    px_rotated, py_rotated, \
+    rot_bounds_x0, rot_bounds_x1, \
+    rot_bounds_y0, rot_bounds_y1 = rotate_particle_coord(px, py, pz,
+                                                         center, width, normal_vector, north_vector)
+
     pixelize_sph_kernel_projection(projection_array,
                                    px_rotated,
                                    py_rotated,

yt/visualization/api.py

@@ -4,6 +4,7 @@
     FITSImageData,
     FITSOffAxisProjection,
     FITSOffAxisSlice,
+    FITSParticleOffAxisProjection,
     FITSParticleProjection,
     FITSProjection,
     FITSSlice,