Commit 4c4344ae authored by Taddeus Kroes's avatar Taddeus Kroes

Added rule that generates a quadrants addition.

parent 9396116f
...@@ -17,13 +17,18 @@ def match_add_quadrants(node): ...@@ -17,13 +17,18 @@ def match_add_quadrants(node):
scope = Scope(node) scope = Scope(node)
for sin_q, cos_q in permutations(scope, 2): for sin_q, cos_q in permutations(scope, 2):
if sin_q.is_power(2) and cos_q.is_power(2) \ if sin_q.is_power(2) and cos_q.is_power(2):
and not sin_q.negated and not cos_q.negated:
s, c = sin_q[0], cos_q[0] s, c = sin_q[0], cos_q[0]
if s.is_op(OP_SIN) and c.is_op(OP_COS) and not s.negated \ if not s.is_op(OP_SIN) or not c.is_op(OP_COS) or s.negated \
and not c.negated and s[0] == c[0]: or c.negated or s[0] != c[0]:
continue
if not sin_q.negated and not cos_q.negated:
p.append(P(node, add_quadrants, (scope, sin_q, cos_q))) p.append(P(node, add_quadrants, (scope, sin_q, cos_q)))
elif sin_q.negated == 1 and cos_q.negated == 1:
p.append(P(node, factor_out_quadrant_negation,
(scope, sin_q, cos_q)))
return p return p
...@@ -42,6 +47,21 @@ def add_quadrants(root, args): ...@@ -42,6 +47,21 @@ def add_quadrants(root, args):
MESSAGES[add_quadrants] = _('Add the sinus and cosinus quadrants to 1.') MESSAGES[add_quadrants] = _('Add the sinus and cosinus quadrants to 1.')
def factor_out_quadrant_negation(root, args):
"""
-sin(t) ^ 2 - cos(t) ^ 2 -> -(sin(t) ^ 2 + cos(t) ^ 2) # -> -1
"""
scope, s, c = args
scope.replace(s, -(+s + +c))
scope.remove(c)
return scope.as_nary_node()
MESSAGES[factor_out_quadrant_negation] = _('Factor out the negations of {2} ' \
'and {3} to be able to reduce the quadrant addition to 1.')
def match_negated_parameter(node): def match_negated_parameter(node):
""" """
sin(-t) -> -sin(t) sin(-t) -> -sin(t)
......
# vim: set fileencoding=utf-8 : # vim: set fileencoding=utf-8 :
from src.rules.goniometry import match_add_quadrants, add_quadrants, \ from src.rules.goniometry import match_add_quadrants, add_quadrants, \
match_negated_parameter, negated_sinus_parameter, is_pi_frac, \ factor_out_quadrant_negation, match_negated_parameter, \
negated_cosinus_parameter, match_standard_radian, standard_radian negated_sinus_parameter, is_pi_frac, negated_cosinus_parameter, \
match_standard_radian, standard_radian
from src.node import PI, OP_SIN, OP_COS, OP_TAN, sin, cos, tan, Scope from src.node import PI, OP_SIN, OP_COS, OP_TAN, sin, cos, tan, Scope
from src.possibilities import Possibility as P from src.possibilities import Possibility as P
from tests.rulestestcase import RulesTestCase, tree from tests.rulestestcase import RulesTestCase, tree
...@@ -38,6 +39,10 @@ class TestRulesGoniometry(RulesTestCase): ...@@ -38,6 +39,10 @@ class TestRulesGoniometry(RulesTestCase):
root = tree('sin(t) ^ 2 - cos(t) ^ 2') root = tree('sin(t) ^ 2 - cos(t) ^ 2')
self.assertEqualPos(match_add_quadrants(root), []) self.assertEqualPos(match_add_quadrants(root), [])
s, c = root = tree('-sin(t) ^ 2 - cos(t) ^ 2')
self.assertEqualPos(match_add_quadrants(root),
[P(root, factor_out_quadrant_negation, (Scope(root), s, c))])
def test_add_quadrants(self): def test_add_quadrants(self):
s, c = root = tree('sin(t) ^ 2 + cos(t) ^ 2') s, c = root = tree('sin(t) ^ 2 + cos(t) ^ 2')
self.assertEqual(add_quadrants(root, (Scope(root), s, c)), 1) self.assertEqual(add_quadrants(root, (Scope(root), s, c)), 1)
...@@ -46,6 +51,11 @@ class TestRulesGoniometry(RulesTestCase): ...@@ -46,6 +51,11 @@ class TestRulesGoniometry(RulesTestCase):
(c, a), s = root (c, a), s = root
self.assertEqual(add_quadrants(root, (Scope(root), s, c)), expect) self.assertEqual(add_quadrants(root, (Scope(root), s, c)), expect)
def test_factor_out_quadrant_negation(self):
r, e = tree('-sin(t) ^ 2 - cos(t) ^ 2, -(sin(t) ^ 2 + cos(t) ^ 2)')
s, c = r
self.assertEqual(factor_out_quadrant_negation(r, (Scope(r), s, c)), e)
def test_match_negated_parameter(self): def test_match_negated_parameter(self):
s, c = tree('sin -t, cos -t') s, c = tree('sin -t, cos -t')
t = s[0] t = s[0]
......
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