def test_operations_poly(model):
m, x, y, z = model
expr = x * x * x + 2 * y * y
assert isinstance(expr, Expr)
assert expr[x] == 0.0
assert expr[y] == 0.0
assert expr[CONST] == 0.0
assert expr[Term(x, x, x)] == 1.0
assert expr[Term(y, y)] == 2.0
assert expr.terms == (x**3 + 2 * y**2).terms
def _import_objective(self):
picosSense, picosObjective = self.ext.objective
# Retrieve objective sense.
if picosSense in ("find", "min"):
minimize = True
scipSense = "minimize"
elif picosSense == "max":
minimize = False
scipSense = "maximize"
else:
raise NotImplementedError(
"Objective sense '{0}' not supported by SCIP.".format(
picosSense))
# Import objective function.
if isinstance(picosObjective, AffinExp):
scipObjective = self._scalar_affinexp_pic2scip(picosObjective)
elif isinstance(picosObjective, QuadExp):
scipObjective = self._convert_quadratic_objective(
picosObjective, minimize)
else:
raise NotImplementedError(
"Objective of type '{0}' not supported by SCIP.".format(
type(picosObjective)))
# HACK: Remove a constant term from the objective as this is not allowed
# by SCIP under Python 2. (Not sure if the term is stored or
# dropped under Python 3, but no exception is thrown there.)
from pyscipopt.scip import Term
constantTerm = Term()
if constantTerm in scipObjective.terms:
scipObjective.terms.pop(constantTerm)
self.int.setObjective(scipObjective, scipSense)
def test_power_for_quadratic(model):
m, x, y, z = model
expr = x**2 + x + 1
assert isinstance(expr, Expr)
assert expr[Term(x, x)] == 1.0
assert expr[x] == 1.0
assert expr[CONST] == 1.0
assert len(expr.terms) == 3
assert (x**2).terms == (x * x).terms
assert ((x + 3)**2).terms == (x**2 + 6 * x + 9).terms
def test_operations_quadratic(model):
m, x, y, z = model
expr = x * x
assert isinstance(expr, Expr)
assert expr[x] == 0.0
assert expr[y] == 0.0
assert expr[CONST] == 0.0
assert expr[Term(x, x)] == 1.0
expr = x * y
assert isinstance(expr, Expr)
assert expr[x] == 0.0
assert expr[y] == 0.0
assert expr[CONST] == 0.0
assert expr[Term(x, y)] == 1.0
expr = (x - 1) * (y + 1)
assert isinstance(expr, Expr)
assert expr[x] == 1.0
assert expr[y] == -1.0
assert expr[CONST] == -1.0
assert expr[Term(x, y)] == 1.0
import pytest
from pyscipopt import Model, sqrt, log, exp
from pyscipopt.scip import Expr, GenExpr, ExprCons, Term, quicksum
@pytest.fixture(scope="module")
def model():
m = Model()
x = m.addVar("x")
y = m.addVar("y")
z = m.addVar("z")
return m, x, y, z
CONST = Term()
def test_upgrade(model):
m, x, y, z = model
expr = x + y
assert isinstance(expr, Expr)
expr += exp(z)
assert isinstance(expr, GenExpr)
expr = x + y
assert isinstance(expr, Expr)
expr -= exp(z)
assert isinstance(expr, GenExpr)
expr = x + y