matplotlib · mdboom · Oct 14, 2015 · Oct 15, 2015
diff --git a/lib/matplotlib/cbook.py b/lib/matplotlib/cbook.py
@@ -2241,6 +2241,21 @@ def _reshape_2D(X):
     return X
 
 
+def ensure_3d(arr):
+    """
+    Return a version of arr with ndim==3, with extra dimensions added
+    at the end of arr.shape as needed.
+    """
+    arr = np.asanyarray(arr)
+    if arr.ndim == 1:
+        arr = arr[:, None, None]
+    elif arr.ndim == 2:
+        arr = arr[:, :, None]
+    elif arr.ndim > 3 or arr.ndim < 1:
+        raise ValueError("cannot convert arr to 3-dimensional")
+    return arr
+
+
 def violin_stats(X, method, points=100):
     '''
     Returns a list of dictionaries of data which can be used to draw a series

diff --git a/lib/matplotlib/path.py b/lib/matplotlib/path.py
@@ -24,7 +24,7 @@
 from numpy import ma
 
 from matplotlib import _path
-from matplotlib.cbook import simple_linear_interpolation, maxdict
+from matplotlib.cbook import simple_linear_interpolation, maxdict, ensure_3d
 from matplotlib import rcParams
 
 
@@ -988,7 +988,7 @@ def get_path_collection_extents(
     if len(paths) == 0:
         raise ValueError("No paths provided")
     return Bbox.from_extents(*_path.get_path_collection_extents(
-        master_transform, paths, np.atleast_3d(transforms),
+        master_transform, paths, ensure_3d(transforms),
         offsets, offset_transform))
 
 

diff --git a/lib/matplotlib/tests/test_cbook.py b/lib/matplotlib/tests/test_cbook.py
@@ -376,3 +376,11 @@ def test_step_fails():
                   np.arange(12))
     assert_raises(ValueError, cbook._step_validation,
                   np.arange(12), np.arange(3))
+
+
+def test_ensure_3d():
+    assert_array_equal([[[1]], [[2]], [[3]]],
+                       cbook.ensure_3d([1, 2, 3]))
+    assert_array_equal([[[1], [2]], [[3], [4]]],
+                       cbook.ensure_3d([[1, 2], [3, 4]]))
+    assert_raises(ValueError, cbook.ensure_3d, [[[[1]]]])
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -48,6 +48,7 @@
     from sets import Set as set
 
 from .path import Path
+from .cbook import ensure_3d
 
 DEBUG = False
 # we need this later, but this is very expensive to set up
@@ -667,7 +668,7 @@ def count_overlaps(self, bboxes):
         bboxes is a sequence of :class:`BboxBase` objects
         """
         return count_bboxes_overlapping_bbox(
-            self, np.atleast_3d([np.array(x) for x in bboxes]))
+            self, ensure_3d([np.array(x) for x in bboxes]))
 
     def expanded(self, sw, sh):
         """

diff --git a/src/_backend_agg.h b/src/_backend_agg.h
@@ -922,22 +922,6 @@ inline void RendererAgg::_draw_path_collection_generic(GCAgg &gc,
     typedef agg::conv_curve<snapped_t> snapped_curve_t;
     typedef agg::conv_curve<clipped_t> curve_t;
 
-    if (offsets.dim(0) != 0 && offsets.dim(1) != 2) {
-        throw "Offsets array must be Nx2 or empty";
-    }
-
-    if (facecolors.dim(0) != 0 && facecolors.dim(1) != 4) {
-        throw "Facecolors array must be a Nx4 array or empty";
-    }
-
-    if (edgecolors.dim(0) != 0 && edgecolors.dim(1) != 4) {
-        throw "Edgecolors array must by Nx4 or empty";
-    }
-
-    if (transforms.dim(0) != 0 && (transforms.dim(1) != 3 || transforms.dim(2) != 3)) {
-        throw "Transforms array must by Nx3x3 or empty";
-    }
-
     size_t Npaths = path_generator.num_paths();
     size_t Noffsets = offsets.size();
     size_t N = std::max(Npaths, Noffsets);
@@ -1266,14 +1250,6 @@ inline void RendererAgg::draw_gouraud_triangle(GCAgg &gc,
     set_clipbox(gc.cliprect, theRasterizer);
     bool has_clippath = render_clippath(gc.clippath.path, gc.clippath.trans);
 
-    if (points.dim(0) != 3 || points.dim(1) != 2) {
-        throw "points must be a 3x2 array";
-    }
-
-    if (colors.dim(0) != 3 || colors.dim(1) != 4) {
-        throw "colors must be a 3x4 array";
-    }
-
     _draw_gouraud_triangle(points, colors, trans, has_clippath);
 }
 
@@ -1288,18 +1264,6 @@ inline void RendererAgg::draw_gouraud_triangles(GCAgg &gc,
     set_clipbox(gc.cliprect, theRasterizer);
     bool has_clippath = render_clippath(gc.clippath.path, gc.clippath.trans);
 
-    if (points.dim(1) != 3 || points.dim(2) != 2) {
-        throw "points must be a Nx3x2 array";
-    }
-
-    if (colors.dim(1) != 3 || colors.dim(2) != 4) {
-        throw "colors must be a Nx3x4 array";
-    }
-
-    if (points.dim(0) != colors.dim(0)) {
-        throw "points and colors arrays must be the same length";
-    }
-
     for (int i = 0; i < points.dim(0); ++i) {
         typename PointArray::sub_t point = points[i];
         typename ColorArray::sub_t color = colors[i];

diff --git a/src/_backend_agg_wrapper.cpp b/src/_backend_agg_wrapper.cpp
@@ -340,15 +340,15 @@ PyRendererAgg_draw_path_collection(PyRendererAgg *self, PyObject *args, PyObject
                           &convert_trans_affine,
                           &master_transform,
                           &pathobj,
-                          &transforms.converter,
+                          &convert_transforms,
                           &transforms,
-                          &offsets.converter,
+                          &convert_points,
                           &offsets,
                           &convert_trans_affine,
                           &offset_trans,
-                          &facecolors.converter,
+                          &convert_colors,
                           &facecolors,
-                          &edgecolors.converter,
+                          &convert_colors,
                           &edgecolors,
                           &linewidths.converter,
                           &linewidths,
@@ -411,14 +411,14 @@ static PyObject *PyRendererAgg_draw_quad_mesh(PyRendererAgg *self, PyObject *arg
                           &mesh_height,
                           &coordinates.converter,
                           &coordinates,
-                          &offsets.converter,
+                          &convert_points,
                           &offsets,
                           &convert_trans_affine,
                           &offset_trans,
-                          &facecolors.converter,
+                          &convert_colors,
                           &facecolors,
                           &antialiased,
-                          &edgecolors.converter,
+                          &convert_colors,
                           &edgecolors)) {
         return NULL;
     }
@@ -459,6 +459,21 @@ PyRendererAgg_draw_gouraud_triangle(PyRendererAgg *self, PyObject *args, PyObjec
         return NULL;
     }
 
+    if (points.dim(0) != 3 || points.dim(1) != 2) {
+        PyErr_Format(PyExc_ValueError,
+                     "points must be a 3x2 array, got %dx%d",
+                     points.dim(0), points.dim(1));
+        return NULL;
+    }
+
+    if (colors.dim(0) != 3 || colors.dim(1) != 4) {
+        PyErr_Format(PyExc_ValueError,
+                     "colors must be a 3x4 array, got %dx%d",
+                     colors.dim(0), colors.dim(1));
+        return NULL;
+    }
+
+
     CALL_CPP("draw_gouraud_triangle", (self->x->draw_gouraud_triangle(gc, points, colors, trans)));
 
     Py_RETURN_NONE;
@@ -485,6 +500,27 @@ PyRendererAgg_draw_gouraud_triangles(PyRendererAgg *self, PyObject *args, PyObje
         return NULL;
     }
 
+    if (points.dim(1) != 3 || points.dim(2) != 2) {
+        PyErr_Format(PyExc_ValueError,
+                     "points must be a Nx3x2 array, got %dx%dx%d",
+                     points.dim(0), points.dim(1), points.dim(2));
+        return NULL;
+    }
+
+    if (colors.dim(1) != 3 || colors.dim(2) != 4) {
+        PyErr_Format(PyExc_ValueError,
+                     "colors must be a Nx3x4 array, got %dx%dx%d",
+                     colors.dim(0), colors.dim(1), colors.dim(2));
+        return NULL;
+    }
+
+    if (points.dim(0) != colors.dim(0)) {
+        PyErr_Format(PyExc_ValueError,
+                     "points and colors arrays must be the same length, got %d and %d",
+                     points.dim(0), colors.dim(0));
+        return NULL;
+    }
+
     CALL_CPP("draw_gouraud_triangles", self->x->draw_gouraud_triangles(gc, points, colors, trans));
 
     Py_RETURN_NONE;

diff --git a/src/_path_wrapper.cpp b/src/_path_wrapper.cpp
@@ -69,7 +69,7 @@ static PyObject *Py_points_in_path(PyObject *self, PyObject *args, PyObject *kwd
 
     if (!PyArg_ParseTuple(args,
                           "O&dO&O&:points_in_path",
-                          &points.converter,
+                          &convert_points,
                           &points,
                           &r,
                           &convert_path,
@@ -128,7 +128,7 @@ static PyObject *Py_points_on_path(PyObject *self, PyObject *args, PyObject *kwd
 
     if (!PyArg_ParseTuple(args,
                           "O&dO&O&:points_on_path",
-                          &points.converter,
+                          &convert_points,
                           &points,
                           &r,
                           &convert_path,
@@ -200,7 +200,10 @@ static PyObject *Py_update_path_extents(PyObject *self, PyObject *args, PyObject
     }
 
     if (minpos.dim(0) != 2) {
-        PyErr_SetString(PyExc_ValueError, "minpos must be of length 2");
+        PyErr_Format(PyExc_ValueError,
+                     "minpos must be of length 2, got %d",
+                     minpos.dim(0));
+        return NULL;
     }
 
     extent_limits e;
@@ -263,9 +266,9 @@ static PyObject *Py_get_path_collection_extents(PyObject *self, PyObject *args,
                           &convert_trans_affine,
                           &master_transform,
                           &pathsobj,
-                          &transforms.converter,
+                          &convert_transforms,
                           &transforms,
-                          &offsets.converter,
+                          &convert_points,
                           &offsets,
                           &convert_trans_affine,
                           &offset_trans)) {
@@ -319,9 +322,9 @@ static PyObject *Py_point_in_path_collection(PyObject *self, PyObject *args, PyO
                           &convert_trans_affine,
                           &master_transform,
                           &pathsobj,
-                          &transforms.converter,
+                          &convert_transforms,
                           &transforms,
-                          &offsets.converter,
+                          &convert_points,
                           &offsets,
                           &convert_trans_affine,
                           &offset_trans,
@@ -464,7 +467,7 @@ static PyObject *Py_count_bboxes_overlapping_bbox(PyObject *self, PyObject *args
                           "O&O&:count_bboxes_overlapping_bbox",
                           &convert_rect,
                           &bbox,
-                          &bboxes.converter,
+                          &convert_bboxes,
                           &bboxes)) {
         return NULL;
     }

diff --git a/src/py_converters.cpp b/src/py_converters.cpp
@@ -518,4 +518,100 @@ int convert_face(PyObject *color, GCAgg &gc, agg::rgba *rgba)
 
     return 1;
 }
+
+int convert_points(PyObject *obj, void *pointsp)
+{
+    numpy::array_view<double, 2> *points = (numpy::array_view<double, 2> *)pointsp;
+
+    if (obj == NULL || obj == Py_None) {
+        return 1;
+    }
+
+    points->set(obj);
+
+    if (points->dim(0) == 0) {
+        return 1;
+    }
+
+    if (points->dim(1) != 2) {
+        PyErr_Format(PyExc_ValueError,
+                     "Points must be Nx2 array, got %dx%d",
+                     points->dim(0), points->dim(1));
+        return 0;
+    }
+
+    return 1;
+}
+
+int convert_transforms(PyObject *obj, void *transp)
+{
+    numpy::array_view<double, 3> *trans = (numpy::array_view<double, 3> *)transp;
+
+    if (obj == NULL || obj == Py_None) {
+        return 1;
+    }
+
+    trans->set(obj);
+
+    if (trans->dim(0) == 0) {
+        return 1;
+    }
+
+    if (trans->dim(1) != 3 || trans->dim(2) != 3) {
+        PyErr_Format(PyExc_ValueError,
+                     "Transforms must be Nx3x3 array, got %dx%dx%d",
+                     trans->dim(0), trans->dim(1), trans->dim(2));
+        return 0;
+    }
+
+    return 1;
+}
+
+int convert_bboxes(PyObject *obj, void *bboxp)
+{
+    numpy::array_view<double, 3> *bbox = (numpy::array_view<double, 3> *)bboxp;
+
+    if (obj == NULL || obj == Py_None) {
+        return 1;
+    }
+
+    bbox->set(obj);
+
+    if (bbox->dim(0) == 0) {
+        return 1;
+    }
+
+    if (bbox->dim(1) != 2 || bbox->dim(2) != 2) {
+        PyErr_Format(PyExc_ValueError,
+                     "Bbox array must be Nx2x2 array, got %dx%dx%d",
+                     bbox->dim(0), bbox->dim(1), bbox->dim(2));
+        return 0;
+    }
+
+    return 1;
+}
+
+int convert_colors(PyObject *obj, void *colorsp)
+{
+    numpy::array_view<double, 2> *colors = (numpy::array_view<double, 2> *)colorsp;
+
+    if (obj == NULL || obj == Py_None) {
+        return 1;
+    }
+
+    colors->set(obj);
+
+    if (colors->dim(0) == 0) {
+        return 1;
+    }
+
+    if (colors->dim(1) != 4) {
+        PyErr_Format(PyExc_ValueError,
+                     "Colors array must be Nx4 array, got %dx%d",
+                     colors->dim(0), colors->dim(1));
+        return 0;
+    }
+
+    return 1;
+}
 }
diff --git a/src/py_converters.h b/src/py_converters.h
@@ -38,6 +38,10 @@ int convert_snap(PyObject *obj, void *snapp);
 int convert_offset_position(PyObject *obj, void *offsetp);
 int convert_sketch_params(PyObject *obj, void *sketchp);
 int convert_gcagg(PyObject *pygc, void *gcp);
+int convert_points(PyObject *pygc, void *pointsp);
+int convert_transforms(PyObject *pygc, void *transp);
+int convert_bboxes(PyObject *pygc, void *bboxp);
+int convert_colors(PyObject *pygc, void *colorsp);
 
 int convert_face(PyObject *color, GCAgg &gc, agg::rgba *rgba);
 }