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<h1>Source code for matplotlib.tri.tritools</h1><div class="highlight"><pre>
<span></span><span class="sd">"""</span>
<span class="sd">Tools for triangular grids.</span>
<span class="sd">"""</span>
<span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>
<span class="kn">from</span> <span class="nn">matplotlib.tri</span> <span class="k">import</span> <span class="n">Triangulation</span>
<div class="viewcode-block" id="TriAnalyzer"><a class="viewcode-back" href="../../../api/tri_api.html#matplotlib.tri.TriAnalyzer">[docs]</a><span class="k">class</span> <span class="nc">TriAnalyzer</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Define basic tools for triangular mesh analysis and improvement.</span>
<span class="sd"> A TriAnalyzer encapsulates a :class:`~matplotlib.tri.Triangulation`</span>
<span class="sd"> object and provides basic tools for mesh analysis and mesh improvement.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> triangulation : :class:`~matplotlib.tri.Triangulation` object</span>
<span class="sd"> The encapsulated triangulation to analyze.</span>
<span class="sd"> Attributes</span>
<span class="sd"> ----------</span>
<span class="sd"> `scale_factors`</span>
<span class="sd"> """</span>
<span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">triangulation</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">triangulation</span><span class="p">,</span> <span class="n">Triangulation</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Expected a Triangulation object"</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span> <span class="o">=</span> <span class="n">triangulation</span>
<span class="nd">@property</span>
<span class="k">def</span> <span class="nf">scale_factors</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Factors to rescale the triangulation into a unit square.</span>
<span class="sd"> Returns *k*, tuple of 2 scale factors.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> k : tuple of 2 floats (kx, ky)</span>
<span class="sd"> Tuple of floats that would rescale the triangulation :</span>
<span class="sd"> ``[triangulation.x * kx, triangulation.y * ky]``</span>
<span class="sd"> fits exactly inside a unit square.</span>
<span class="sd"> """</span>
<span class="n">compressed_triangles</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">get_masked_triangles</span><span class="p">()</span>
<span class="n">node_used</span> <span class="o">=</span> <span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">bincount</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">ravel</span><span class="p">(</span><span class="n">compressed_triangles</span><span class="p">),</span>
<span class="n">minlength</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">x</span><span class="o">.</span><span class="n">size</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">0</span><span class="p">)</span>
<span class="k">return</span> <span class="p">(</span><span class="mi">1</span> <span class="o">/</span> <span class="n">np</span><span class="o">.</span><span class="n">ptp</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">x</span><span class="p">[</span><span class="n">node_used</span><span class="p">]),</span>
<span class="mi">1</span> <span class="o">/</span> <span class="n">np</span><span class="o">.</span><span class="n">ptp</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">y</span><span class="p">[</span><span class="n">node_used</span><span class="p">]))</span>
<div class="viewcode-block" id="TriAnalyzer.circle_ratios"><a class="viewcode-back" href="../../../api/tri_api.html#matplotlib.tri.TriAnalyzer.circle_ratios">[docs]</a> <span class="k">def</span> <span class="nf">circle_ratios</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">rescale</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Returns a measure of the triangulation triangles flatness.</span>
<span class="sd"> The ratio of the incircle radius over the circumcircle radius is a</span>
<span class="sd"> widely used indicator of a triangle flatness.</span>
<span class="sd"> It is always ``<= 0.5`` and ``== 0.5`` only for equilateral</span>
<span class="sd"> triangles. Circle ratios below 0.01 denote very flat triangles.</span>
<span class="sd"> To avoid unduly low values due to a difference of scale between the 2</span>
<span class="sd"> axis, the triangular mesh can first be rescaled to fit inside a unit</span>
<span class="sd"> square with :attr:`scale_factors` (Only if *rescale* is True, which is</span>
<span class="sd"> its default value).</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> rescale : boolean, optional</span>
<span class="sd"> If True, a rescaling will be internally performed (based on</span>
<span class="sd"> :attr:`scale_factors`, so that the (unmasked) triangles fit</span>
<span class="sd"> exactly inside a unit square mesh. Default is True.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> circle_ratios : masked array</span>
<span class="sd"> Ratio of the incircle radius over the</span>
<span class="sd"> circumcircle radius, for each 'rescaled' triangle of the</span>
<span class="sd"> encapsulated triangulation.</span>
<span class="sd"> Values corresponding to masked triangles are masked out.</span>
<span class="sd"> """</span>
<span class="c1"># Coords rescaling</span>
<span class="k">if</span> <span class="n">rescale</span><span class="p">:</span>
<span class="p">(</span><span class="n">kx</span><span class="p">,</span> <span class="n">ky</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">scale_factors</span>
<span class="k">else</span><span class="p">:</span>
<span class="p">(</span><span class="n">kx</span><span class="p">,</span> <span class="n">ky</span><span class="p">)</span> <span class="o">=</span> <span class="p">(</span><span class="mf">1.0</span><span class="p">,</span> <span class="mf">1.0</span><span class="p">)</span>
<span class="n">pts</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">vstack</span><span class="p">([</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">x</span><span class="o">*</span><span class="n">kx</span><span class="p">,</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">y</span><span class="o">*</span><span class="n">ky</span><span class="p">])</span><span class="o">.</span><span class="n">T</span>
<span class="n">tri_pts</span> <span class="o">=</span> <span class="n">pts</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">triangles</span><span class="p">]</span>
<span class="c1"># Computes the 3 side lengths</span>
<span class="n">a</span> <span class="o">=</span> <span class="n">tri_pts</span><span class="p">[:,</span> <span class="mi">1</span><span class="p">,</span> <span class="p">:]</span> <span class="o">-</span> <span class="n">tri_pts</span><span class="p">[:,</span> <span class="mi">0</span><span class="p">,</span> <span class="p">:]</span>
<span class="n">b</span> <span class="o">=</span> <span class="n">tri_pts</span><span class="p">[:,</span> <span class="mi">2</span><span class="p">,</span> <span class="p">:]</span> <span class="o">-</span> <span class="n">tri_pts</span><span class="p">[:,</span> <span class="mi">1</span><span class="p">,</span> <span class="p">:]</span>
<span class="n">c</span> <span class="o">=</span> <span class="n">tri_pts</span><span class="p">[:,</span> <span class="mi">0</span><span class="p">,</span> <span class="p">:]</span> <span class="o">-</span> <span class="n">tri_pts</span><span class="p">[:,</span> <span class="mi">2</span><span class="p">,</span> <span class="p">:]</span>
<span class="n">a</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">hypot</span><span class="p">(</span><span class="n">a</span><span class="p">[:,</span> <span class="mi">0</span><span class="p">],</span> <span class="n">a</span><span class="p">[:,</span> <span class="mi">1</span><span class="p">])</span>
<span class="n">b</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">hypot</span><span class="p">(</span><span class="n">b</span><span class="p">[:,</span> <span class="mi">0</span><span class="p">],</span> <span class="n">b</span><span class="p">[:,</span> <span class="mi">1</span><span class="p">])</span>
<span class="n">c</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">hypot</span><span class="p">(</span><span class="n">c</span><span class="p">[:,</span> <span class="mi">0</span><span class="p">],</span> <span class="n">c</span><span class="p">[:,</span> <span class="mi">1</span><span class="p">])</span>
<span class="c1"># circumcircle and incircle radii</span>
<span class="n">s</span> <span class="o">=</span> <span class="p">(</span><span class="n">a</span><span class="o">+</span><span class="n">b</span><span class="o">+</span><span class="n">c</span><span class="p">)</span><span class="o">*</span><span class="mf">0.5</span>
<span class="n">prod</span> <span class="o">=</span> <span class="n">s</span><span class="o">*</span><span class="p">(</span><span class="n">a</span><span class="o">+</span><span class="n">b</span><span class="o">-</span><span class="n">s</span><span class="p">)</span><span class="o">*</span><span class="p">(</span><span class="n">a</span><span class="o">+</span><span class="n">c</span><span class="o">-</span><span class="n">s</span><span class="p">)</span><span class="o">*</span><span class="p">(</span><span class="n">b</span><span class="o">+</span><span class="n">c</span><span class="o">-</span><span class="n">s</span><span class="p">)</span>
<span class="c1"># We have to deal with flat triangles with infinite circum_radius</span>
<span class="n">bool_flat</span> <span class="o">=</span> <span class="p">(</span><span class="n">prod</span> <span class="o">==</span> <span class="mf">0.</span><span class="p">)</span>
<span class="k">if</span> <span class="n">np</span><span class="o">.</span><span class="n">any</span><span class="p">(</span><span class="n">bool_flat</span><span class="p">):</span>
<span class="c1"># Pathologic flow</span>
<span class="n">ntri</span> <span class="o">=</span> <span class="n">tri_pts</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="n">circum_radius</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">empty</span><span class="p">(</span><span class="n">ntri</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">float64</span><span class="p">)</span>
<span class="n">circum_radius</span><span class="p">[</span><span class="n">bool_flat</span><span class="p">]</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">inf</span>
<span class="n">abc</span> <span class="o">=</span> <span class="n">a</span><span class="o">*</span><span class="n">b</span><span class="o">*</span><span class="n">c</span>
<span class="n">circum_radius</span><span class="p">[</span><span class="o">~</span><span class="n">bool_flat</span><span class="p">]</span> <span class="o">=</span> <span class="n">abc</span><span class="p">[</span><span class="o">~</span><span class="n">bool_flat</span><span class="p">]</span> <span class="o">/</span> <span class="p">(</span>
<span class="mf">4.0</span><span class="o">*</span><span class="n">np</span><span class="o">.</span><span class="n">sqrt</span><span class="p">(</span><span class="n">prod</span><span class="p">[</span><span class="o">~</span><span class="n">bool_flat</span><span class="p">]))</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># Normal optimized flow</span>
<span class="n">circum_radius</span> <span class="o">=</span> <span class="p">(</span><span class="n">a</span><span class="o">*</span><span class="n">b</span><span class="o">*</span><span class="n">c</span><span class="p">)</span> <span class="o">/</span> <span class="p">(</span><span class="mf">4.0</span><span class="o">*</span><span class="n">np</span><span class="o">.</span><span class="n">sqrt</span><span class="p">(</span><span class="n">prod</span><span class="p">))</span>
<span class="n">in_radius</span> <span class="o">=</span> <span class="p">(</span><span class="n">a</span><span class="o">*</span><span class="n">b</span><span class="o">*</span><span class="n">c</span><span class="p">)</span> <span class="o">/</span> <span class="p">(</span><span class="mf">4.0</span><span class="o">*</span><span class="n">circum_radius</span><span class="o">*</span><span class="n">s</span><span class="p">)</span>
<span class="n">circle_ratio</span> <span class="o">=</span> <span class="n">in_radius</span><span class="o">/</span><span class="n">circum_radius</span>
<span class="n">mask</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">mask</span>
<span class="k">if</span> <span class="n">mask</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">return</span> <span class="n">circle_ratio</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="n">np</span><span class="o">.</span><span class="n">ma</span><span class="o">.</span><span class="n">array</span><span class="p">(</span><span class="n">circle_ratio</span><span class="p">,</span> <span class="n">mask</span><span class="o">=</span><span class="n">mask</span><span class="p">)</span></div>
<div class="viewcode-block" id="TriAnalyzer.get_flat_tri_mask"><a class="viewcode-back" href="../../../api/tri_api.html#matplotlib.tri.TriAnalyzer.get_flat_tri_mask">[docs]</a> <span class="k">def</span> <span class="nf">get_flat_tri_mask</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">min_circle_ratio</span><span class="o">=</span><span class="mf">0.01</span><span class="p">,</span> <span class="n">rescale</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Eliminates excessively flat border triangles from the triangulation.</span>
<span class="sd"> Returns a mask *new_mask* which allows to clean the encapsulated</span>
<span class="sd"> triangulation from its border-located flat triangles</span>
<span class="sd"> (according to their :meth:`circle_ratios`).</span>
<span class="sd"> This mask is meant to be subsequently applied to the triangulation</span>
<span class="sd"> using :func:`matplotlib.tri.Triangulation.set_mask`.</span>
<span class="sd"> *new_mask* is an extension of the initial triangulation mask</span>
<span class="sd"> in the sense that an initially masked triangle will remain masked.</span>
<span class="sd"> The *new_mask* array is computed recursively; at each step flat</span>
<span class="sd"> triangles are removed only if they share a side with the current mesh</span>
<span class="sd"> border. Thus no new holes in the triangulated domain will be created.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> min_circle_ratio : float, optional</span>
<span class="sd"> Border triangles with incircle/circumcircle radii ratio r/R will</span>
<span class="sd"> be removed if r/R < *min_circle_ratio*. Default value: 0.01</span>
<span class="sd"> rescale : boolean, optional</span>
<span class="sd"> If True, a rescaling will first be internally performed (based on</span>
<span class="sd"> :attr:`scale_factors` ), so that the (unmasked) triangles fit</span>
<span class="sd"> exactly inside a unit square mesh. This rescaling accounts for the</span>
<span class="sd"> difference of scale which might exist between the 2 axis. Default</span>
<span class="sd"> (and recommended) value is True.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> new_mask : array-like of booleans</span>
<span class="sd"> Mask to apply to encapsulated triangulation.</span>
<span class="sd"> All the initially masked triangles remain masked in the</span>
<span class="sd"> *new_mask*.</span>
<span class="sd"> Notes</span>
<span class="sd"> -----</span>
<span class="sd"> The rationale behind this function is that a Delaunay</span>
<span class="sd"> triangulation - of an unstructured set of points - sometimes contains</span>
<span class="sd"> almost flat triangles at its border, leading to artifacts in plots</span>
<span class="sd"> (especially for high-resolution contouring).</span>
<span class="sd"> Masked with computed *new_mask*, the encapsulated</span>
<span class="sd"> triangulation would contain no more unmasked border triangles</span>
<span class="sd"> with a circle ratio below *min_circle_ratio*, thus improving the</span>
<span class="sd"> mesh quality for subsequent plots or interpolation.</span>
<span class="sd"> """</span>
<span class="c1"># Recursively computes the mask_current_borders, true if a triangle is</span>
<span class="c1"># at the border of the mesh OR touching the border through a chain of</span>
<span class="c1"># invalid aspect ratio masked_triangles.</span>
<span class="n">ntri</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">triangles</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="n">mask_bad_ratio</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">circle_ratios</span><span class="p">(</span><span class="n">rescale</span><span class="p">)</span> <span class="o"><</span> <span class="n">min_circle_ratio</span>
<span class="n">current_mask</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">mask</span>
<span class="k">if</span> <span class="n">current_mask</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">current_mask</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">zeros</span><span class="p">(</span><span class="n">ntri</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="nb">bool</span><span class="p">)</span>
<span class="n">valid_neighbors</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">copy</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">neighbors</span><span class="p">)</span>
<span class="n">renum_neighbors</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">arange</span><span class="p">(</span><span class="n">ntri</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">int32</span><span class="p">)</span>
<span class="n">nadd</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="k">while</span> <span class="n">nadd</span> <span class="o">!=</span> <span class="mi">0</span><span class="p">:</span>
<span class="c1"># The active wavefront is the triangles from the border (unmasked</span>
<span class="c1"># but with a least 1 neighbor equal to -1</span>
<span class="n">wavefront</span> <span class="o">=</span> <span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">min</span><span class="p">(</span><span class="n">valid_neighbors</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span> <span class="o">==</span> <span class="o">-</span><span class="mi">1</span><span class="p">)</span> <span class="o">&</span> <span class="o">~</span><span class="n">current_mask</span>
<span class="c1"># The element from the active wavefront will be masked if their</span>
<span class="c1"># circle ratio is bad.</span>
<span class="n">added_mask</span> <span class="o">=</span> <span class="n">wavefront</span> <span class="o">&</span> <span class="n">mask_bad_ratio</span>
<span class="n">current_mask</span> <span class="o">=</span> <span class="n">added_mask</span> <span class="o">|</span> <span class="n">current_mask</span>
<span class="n">nadd</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">sum</span><span class="p">(</span><span class="n">added_mask</span><span class="p">)</span>
<span class="c1"># now we have to update the tables valid_neighbors</span>
<span class="n">valid_neighbors</span><span class="p">[</span><span class="n">added_mask</span><span class="p">,</span> <span class="p">:]</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="n">renum_neighbors</span><span class="p">[</span><span class="n">added_mask</span><span class="p">]</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span>
<span class="n">valid_neighbors</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">where</span><span class="p">(</span><span class="n">valid_neighbors</span> <span class="o">==</span> <span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">,</span>
<span class="n">renum_neighbors</span><span class="p">[</span><span class="n">valid_neighbors</span><span class="p">])</span>
<span class="k">return</span> <span class="n">np</span><span class="o">.</span><span class="n">ma</span><span class="o">.</span><span class="n">filled</span><span class="p">(</span><span class="n">current_mask</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span></div>
<span class="k">def</span> <span class="nf">_get_compressed_triangulation</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">return_tri_renum</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span>
<span class="n">return_node_renum</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Compress (if masked) the encapsulated triangulation.</span>
<span class="sd"> Returns minimal-length triangles array (*compressed_triangles*) and</span>
<span class="sd"> coordinates arrays (*compressed_x*, *compressed_y*) that can still</span>
<span class="sd"> describe the unmasked triangles of the encapsulated triangulation.</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> return_tri_renum : boolean, optional</span>
<span class="sd"> Indicates whether a renumbering table to translate the triangle</span>
<span class="sd"> numbers from the encapsulated triangulation numbering into the</span>
<span class="sd"> new (compressed) renumbering will be returned.</span>
<span class="sd"> return_node_renum : boolean, optional</span>
<span class="sd"> Indicates whether a renumbering table to translate the nodes</span>
<span class="sd"> numbers from the encapsulated triangulation numbering into the</span>
<span class="sd"> new (compressed) renumbering will be returned.</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> compressed_triangles : array-like</span>
<span class="sd"> the returned compressed triangulation triangles</span>
<span class="sd"> compressed_x : array-like</span>
<span class="sd"> the returned compressed triangulation 1st coordinate</span>
<span class="sd"> compressed_y : array-like</span>
<span class="sd"> the returned compressed triangulation 2nd coordinate</span>
<span class="sd"> tri_renum : array-like of integers</span>
<span class="sd"> renumbering table to translate the triangle numbers from the</span>
<span class="sd"> encapsulated triangulation into the new (compressed) renumbering.</span>
<span class="sd"> -1 for masked triangles (deleted from *compressed_triangles*).</span>
<span class="sd"> Returned only if *return_tri_renum* is True.</span>
<span class="sd"> node_renum : array-like of integers</span>
<span class="sd"> renumbering table to translate the point numbers from the</span>
<span class="sd"> encapsulated triangulation into the new (compressed) renumbering.</span>
<span class="sd"> -1 for unused points (i.e. those deleted from *compressed_x* and</span>
<span class="sd"> *compressed_y*). Returned only if *return_node_renum* is True.</span>
<span class="sd"> """</span>
<span class="c1"># Valid triangles and renumbering</span>
<span class="n">tri_mask</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">mask</span>
<span class="n">compressed_triangles</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">get_masked_triangles</span><span class="p">()</span>
<span class="n">ntri</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">triangles</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="n">tri_renum</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_total_to_compress_renum</span><span class="p">(</span><span class="n">tri_mask</span><span class="p">,</span> <span class="n">ntri</span><span class="p">)</span>
<span class="c1"># Valid nodes and renumbering</span>
<span class="n">node_mask</span> <span class="o">=</span> <span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">bincount</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">ravel</span><span class="p">(</span><span class="n">compressed_triangles</span><span class="p">),</span>
<span class="n">minlength</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">x</span><span class="o">.</span><span class="n">size</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span><span class="p">)</span>
<span class="n">compressed_x</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">x</span><span class="p">[</span><span class="o">~</span><span class="n">node_mask</span><span class="p">]</span>
<span class="n">compressed_y</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_triangulation</span><span class="o">.</span><span class="n">y</span><span class="p">[</span><span class="o">~</span><span class="n">node_mask</span><span class="p">]</span>
<span class="n">node_renum</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_total_to_compress_renum</span><span class="p">(</span><span class="n">node_mask</span><span class="p">)</span>
<span class="c1"># Now renumbering the valid triangles nodes</span>
<span class="n">compressed_triangles</span> <span class="o">=</span> <span class="n">node_renum</span><span class="p">[</span><span class="n">compressed_triangles</span><span class="p">]</span>
<span class="c1"># 4 cases possible for return</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">return_tri_renum</span><span class="p">:</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">return_node_renum</span><span class="p">:</span>
<span class="k">return</span> <span class="n">compressed_triangles</span><span class="p">,</span> <span class="n">compressed_x</span><span class="p">,</span> <span class="n">compressed_y</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="p">(</span><span class="n">compressed_triangles</span><span class="p">,</span> <span class="n">compressed_x</span><span class="p">,</span> <span class="n">compressed_y</span><span class="p">,</span>
<span class="n">node_renum</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">return_node_renum</span><span class="p">:</span>
<span class="k">return</span> <span class="p">(</span><span class="n">compressed_triangles</span><span class="p">,</span> <span class="n">compressed_x</span><span class="p">,</span> <span class="n">compressed_y</span><span class="p">,</span>
<span class="n">tri_renum</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="p">(</span><span class="n">compressed_triangles</span><span class="p">,</span> <span class="n">compressed_x</span><span class="p">,</span> <span class="n">compressed_y</span><span class="p">,</span>
<span class="n">tri_renum</span><span class="p">,</span> <span class="n">node_renum</span><span class="p">)</span>
<span class="nd">@staticmethod</span>
<span class="k">def</span> <span class="nf">_total_to_compress_renum</span><span class="p">(</span><span class="n">mask</span><span class="p">,</span> <span class="n">n</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Parameters</span>
<span class="sd"> ----------</span>
<span class="sd"> mask : 1d boolean array or None</span>
<span class="sd"> mask</span>
<span class="sd"> n : integer</span>
<span class="sd"> length of the mask. Useful only id mask can be None</span>
<span class="sd"> Returns</span>
<span class="sd"> -------</span>
<span class="sd"> renum : integer array</span>
<span class="sd"> array so that (`valid_array` being a compressed array</span>
<span class="sd"> based on a `masked_array` with mask *mask*) :</span>
<span class="sd"> - For all i such as mask[i] = False:</span>
<span class="sd"> valid_array[renum[i]] = masked_array[i]</span>
<span class="sd"> - For all i such as mask[i] = True:</span>
<span class="sd"> renum[i] = -1 (invalid value)</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="n">n</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">n</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">size</span><span class="p">(</span><span class="n">mask</span><span class="p">)</span>
<span class="k">if</span> <span class="n">mask</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">renum</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">full</span><span class="p">(</span><span class="n">n</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">int32</span><span class="p">)</span> <span class="c1"># Default num is -1</span>
<span class="n">valid</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">arange</span><span class="p">(</span><span class="n">n</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">int32</span><span class="p">)[</span><span class="o">~</span><span class="n">mask</span><span class="p">]</span>
<span class="n">renum</span><span class="p">[</span><span class="n">valid</span><span class="p">]</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">arange</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">size</span><span class="p">(</span><span class="n">valid</span><span class="p">,</span> <span class="mi">0</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">int32</span><span class="p">)</span>
<span class="k">return</span> <span class="n">renum</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="n">np</span><span class="o">.</span><span class="n">arange</span><span class="p">(</span><span class="n">n</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">int32</span><span class="p">)</span></div>
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