examples/squares.py

   1 #!/usr/bin/env python3
   2
   3 from pypol import *
   4
   5 a, x, y, z = symbols('a x y z')
   6
   7 sq1 = Le(0, x) & Le(x, 2) & Le(0, y) & Le(y, 2)
   8 sq2 = Le(2, x) & Le(x, 4) & Le(2, y) & Le(y, 4)
   9 sq3 = Le(0, x) & Le(x, 3) & Le(0, y) & Le(y, 3)
  10 sq4 = Le(1, x) & Le(x, 2) & Le(1, y) & Le(y, 2)
  11 sq5 = Le(1, x) & Le(x, 2) & Le(1, y)
  12 sq6 = Le(1, x) & Le(x, 2) & Le(1, y) & Eq(y, 3)
  13 sq7 = Le(0, x) & Le(x, 2) & Le(0, y) & Eq(z, 2) & Le(a, 3)
  14 u = Polyhedron([])
  15 x = sq1 - sq2
  16
  17 print('sq1 =', sq1) #print correct square
  18 print('sq2 =', sq2) #print correct square
  19 print('sq3 =', sq3) #print correct square
  20 print('sq4 =', sq4) #print correct square
  21 print('u =', u) #print correct square
  22 print()
  23 print('¬sq1 =', ~sq1) #test compliment
  24 print()
  25 print('sq1 + sq1 =', sq1 + sq2) #test addition
  26 print('sq1 + sq2 =', Polyhedron(sq1 + sq2)) #test addition
  27 print()
  28 print('u + u =', u + u)#test addition
  29 print('u - u =', u - u) #test subtraction
  30 print()
  31 print('sq2 - sq1 =', sq2 - sq1) #test subtraction
  32 print('sq2 - sq1 =', Polyhedron(sq2 - sq1)) #test subtraction
  33 print('sq1 - sq1 =', Polyhedron(sq1 - sq1)) #test subtraction
  34 print()
  35 print('sq1 ∩ sq2 =', sq1 & sq2) #test intersection
  36 print('sq1 ∪ sq2 =', sq1 | sq2) #test union
  37 print()
  38 print('sq1 ⊔ sq2 =', Polyhedron(sq1 | sq2)) # test convex union
  39 print()
  40 print('check if sq1 and sq2 disjoint:', sq1.isdisjoint(sq2)) #should return false
  41 print()
  42 print('sq1 disjoint:', sq1.disjoint()) #make disjoint
  43 print('sq2 disjoint:', sq2.disjoint()) #make disjoint
  44 print()
  45 print('is square 1 universe?:', sq1.isuniverse()) #test if square is universe
  46 print('is u universe?:', u.isuniverse()) #test if square is universe
  47 print()
  48 print('is sq1 a subset of sq2?:', sq1.issubset(sq2)) #test issubset()
  49 print('is sq4 less than sq3?:', sq4.__lt__(sq3)) # test lt(), must be a strict subset
  50 print()
  51 print('lexographic min of sq1:', sq1.lexmin()) #test lexmin()
  52 print('lexographic max of sq1:', sq1.lexmax()) #test lexmin()
  53 print()
  54 print('lexographic min of sq2:', sq2.lexmin()) #test lexmax()
  55 print('lexographic max of sq2:', sq2.lexmax()) #test lexmax()
  56 print()
  57 print('Polyhedral hull of sq1 + sq2 is:', x.polyhedral_hull()) #test polyhedral hull, returns same
  58                                                                #value as Polyhedron(sq1 + sq2)
  59 print()
  60 print('is sq1 bounded?', sq1.isbounded()) #unbounded should return True
  61 print('is sq5 bounded?', sq5.isbounded()) #unbounded should return False
  62 print()
  63 print('sq6:', sq6)
  64 print('sq6 simplified:', sq6.sample())
  65 print()
  66 print('sq7 with out constraints involving y and a', sq7.drop_dims('y a'))
  67