first approx to grapher

trees/Snode_graph.py

@@ -0,0 +1,49 @@
+'''
+__author__ = "Ricardo Montañana Gómez"
+__copyright__ = "Copyright 2020, Ricardo Montañana Gómez"
+__license__ = "MIT"
+__version__ = "0.9"
+Plot 3D views of nodes in Stree
+'''
+
+import numpy as np
+import matplotlib.pyplot as plt
+from mpl_toolkits.mplot3d import Axes3D
+from trees.Snode import Snode
+from trees.Stree import Stree
+
+
+class Snode_graph(Snode):
+
+    def __init__(self, node: Stree):
+        self._plot_size = (8, 8)
+        n = Snode.copy(node)
+        super().__init__(n._clf, n._X, n._y, n._title)
+
+    def set_plot_size(self, size):
+        self._plot_size = size
+
+    def plot_hyperplane(self):
+        # get the splitting hyperplane
+        def hyperplane(x, y): return (-self._interceptor - self._vector[0][0] * x
+                                      - self._vector[0][1] * y) / self._vector[0][2]
+        fig = plt.figure(figsize=self._plot_size)
+        ax = fig.add_subplot(1, 1, 1, projection='3d')
+        tmpx = np.linspace(self._X[:, 0].min(), self._X[:, 0].max())
+        tmpy = np.linspace(self._X[:, 1].min(), self._X[:, 1].max())
+        xx, yy = np.meshgrid(tmpx, tmpy)
+        ax.plot_surface(xx, yy, hyperplane(xx, yy), alpha=.5, antialiased=True,
+                        rstride=1, cstride=1, cmap='seismic')
+        plt.title(self._title)
+        self.plot_distribution(ax)
+        return ax
+
+    def plot_distribution(self, ax: Axes3D = None):
+        if ax is None:
+            fig = plt.figure(figsize=self._plot_size)
+            ax = fig.add_subplot(1, 1, 1, projection='3d')
+        ax.scatter(self._X[:, 0], self._X[:, 1], self._X[:, 2], c=self._y)
+        ax.set_xlabel('X0')
+        ax.set_ylabel('X1')
+        ax.set_zlabel('X2')
+        plt.show()