add issequence function to data and plot functions and examples for geometry

examples/geometry_pyramidal_frustum.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""Example geometry of a pyramidal frustum.
+
+:Date: 2019-12-23
+
+.. module:: geometry_pyramidal_frustum
+  :platform: *nix, Windows
+  :synopsis: Example geometry of a pyramidal frustum.
+
+.. moduleauthor:: Daniel Weschke <daniel.weschke@directbox.de>
+"""
+from pylib.geometry import World, Point, Polygon, Hexahedron
+from pylib.geometry_plot_pylab import cad_wireframe
+
+def geometry():
+  w = World()
+  p0 = Point()
+  p1 = Point(1.00, 0, 0)
+  p2 = Point(1.00, 1, 0)
+  p3 = Point(0.00, 1, 0)
+  p4 = Point(0.25, 0.25, 1)
+  p5 = Point(0.75, 0.25, 1)
+  p6 = Point(0.75, 0.75, 1)
+  p7 = Point(0.25, 0.75, 1)
+  pg0 = Polygon(p0, p1, p2, p3)
+  pg1 = Polygon(p4, p5, p6, p7)
+  pg2 = Polygon(p0, p1, p5, p4)
+  pg3 = Polygon(p2, p3, p7, p6)
+  w.add(pg0, pg1, pg2, pg3)
+  h = Hexahedron()
+  w.add(h)
+  return w
+
+
+if __name__ == "__main__":
+  w = geometry()
+  print(*w)
+  print(w.wireframes_xyz())
+  cad_wireframe(w)