Files
stree/trees/Snode_graph.py

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3.2 KiB
Python

'''
__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)
self._xlimits = (None, None)
self._ylimits = (None, None)
self._zlimits = (None, None)
n = Snode.copy(node)
super().__init__(n._clf, n._X, n._y, n._title)
def set_plot_size(self, size: tuple):
self._plot_size = size
def _is_pure(self) -> bool:
"""is considered pure a leaf node with one label
"""
if self.is_leaf():
return self._belief == 1.
return False
def set_axis_limits(self, limits: tuple):
self._xlimits = limits[0]
self._ylimits = limits[1]
self._zlimits = limits[2]
def _set_graphics_axis(self, ax: Axes3D):
ax.set_xlim(self._xlimits)
ax.set_ylim(self._ylimits)
ax.set_zlim(self._zlimits)
def save_hyperplane(self, save_folder: str = './', save_prefix: str = '', save_seq: int = 1):
_, fig = self.plot_hyperplane()
name = f"{save_folder}{save_prefix}STnode{save_seq}.png"
fig.savefig(name, bbox_inches='tight')
plt.close(fig)
def _get_cmap(self):
cmap = 'jet'
if self._is_pure():
if self._class == 1:
cmap = 'jet_r'
return cmap
def _graph_title(self):
n_class, card = np.unique(self._y, return_counts=True)
return f"{self._title} {n_class} {card}"
def plot_hyperplane(self, plot_distribution: bool = True):
fig = plt.figure(figsize=self._plot_size)
ax = fig.add_subplot(1, 1, 1, projection='3d')
if not self._is_pure():
# Can't plot hyperplane of leaves with one label because it hasn't classiffier
# 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]
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')
self._set_graphics_axis(ax)
if plot_distribution:
self.plot_distribution(ax)
else:
plt.title(self._graph_title())
plt.show()
return ax, fig
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')
plt.title(self._graph_title())
cmap = self._get_cmap()
ax.scatter(self._X[:, 0], self._X[:, 1],
self._X[:, 2], c=self._y, cmap=cmap)
ax.set_xlabel('X0')
ax.set_ylabel('X1')
ax.set_zlabel('X2')
plt.show()