@@ -81,6 +81,40 @@ def strrepr(x): return repr(x) if isinstance(x, str) else str(x)
8181+ ")" )
8282
8383
84+ def matrix_transform (vertices ,mtx ):
85+ """
86+ Transforms a vertex or set of vertices with a matrix mtx of
87+ one dimension higher.
88+
89+ Parameters
90+ ----------
91+ vertices : n-element array or (m, n) array, with m vertices
92+ mtx : (n+1, n+1) matrix
93+ """
94+ values = np .asanyarray (vertices )
95+ _ ,input_dims = mtx .shape
96+ input_dims = input_dims - 1
97+
98+ if (len (values .shape )== 1 ):
99+ # single point
100+ if (values .shape == (input_dims ,)):
101+ point = mtx .dot (np .append (values , [1 ]))
102+ point = point / point [- 1 ]
103+ return point [:input_dims ]
104+ raise RuntimeError ("Invalid vertices provided to transform" )
105+
106+ # multiple points
107+ if (len (values .shape )== 2 and values .shape [1 ]== input_dims ):
108+ points = np .hstack ((values ,np .ones ((values .shape [0 ],1 ))))
109+ points = np .dot (mtx ,points .T ).T
110+ last_coords = points [:,- 1 ]
111+ points = points / last_coords [:,np .newaxis ]
112+ return points [:, :- 1 ]
113+
114+ raise ValueError ("Dimensions of input must match the input dimensions of "
115+ "the transform" )
116+
117+
84118class TransformNode :
85119"""
86120 The base class for anything that participates in the transform tree
@@ -1873,34 +1907,12 @@ def to_values(self):
18731907mtx = self .get_matrix ()
18741908return tuple (mtx [:self .input_dims ].swapaxes (0 ,1 ).flat )
18751909
1876- def _affine_transform (self ,vertices ,mtx ):
1877- """
1878- Default implementation of affine_transform if a C implementation isn't
1879- available
1880- """
1881- values = np .asanyarray (vertices )
1882-
1883- if (len (values .shape )== 1 ):
1884- # single point
1885- if (values .shape == (self .input_dims ,)):
1886- return mtx .dot (np .append (values , [1 ]))[:self .input_dims ]
1887- raise RuntimeError ("Invalid vertices provided to transform" )
1888-
1889- # multiple points
1890- if (len (values .shape )== 2 and values .shape [1 ]== self .input_dims ):
1891- homogeneous = np .hstack ((values ,np .ones ((values .shape [0 ],1 ))))
1892- return np .dot (mtx ,homogeneous .T ).T [:, :- 1 ]
1893-
1894- raise ValueError ("Dimensions of input must match the input dimensions of "
1895- "the transform" )
1896-
18971910@_api .rename_parameter ("3.8" ,"points" ,"values" )
18981911def transform_affine (self ,values ):
18991912mtx = self .get_matrix ()
19001913
19011914# Default to python implementation if C implementation isn't available
1902- transform_fn = (affine_transform if self .input_dims <= 2
1903- else self ._affine_transform )
1915+ transform_fn = (affine_transform if self .input_dims <= 2 else matrix_transform )
19041916
19051917if isinstance (values ,np .ma .MaskedArray ):
19061918tpoints = transform_fn (values .data ,mtx )