From 5d87aa262c407b183f7edeab607b836051dae20b Mon Sep 17 00:00:00 2001
From: Martin Bauer <martin.bauer@fau.de>
Date: Wed, 17 Jan 2018 09:09:30 +0100
Subject: [PATCH] More robust moment specification (now supports non-rational
coefficients)
---
moments.py | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/moments.py b/moments.py
index 84429c4a..14a18329 100644
--- a/moments.py
+++ b/moments.py
@@ -195,18 +195,20 @@ def polynomialToExponentRepresentation(polynomial, dim=3):
x, y, z = MOMENT_SYMBOLS
polynomial = polynomial.expand()
coeffExpTupleRepresentation = []
- for expr, coefficient in polynomial.as_coefficients_dict().items():
+
+ summands = [polynomial] if polynomial.func != sp.Add else polynomial.args
+ for expr in summands:
if len(expr.atoms(sp.Symbol) - set(MOMENT_SYMBOLS)) > 0:
raise ValueError("Invalid moment polynomial: " + str(expr))
- x_exp, y_exp, z_exp = sp.Wild('xexp'), sp.Wild('yexp'), sp.Wild('zc')
- matchRes = expr.match(x**x_exp * y**y_exp * z**z_exp)
+ c, x_exp, y_exp, z_exp = sp.Wild('c'), sp.Wild('xexp'), sp.Wild('yexp'), sp.Wild('zc')
+ matchRes = expr.match(c * x**x_exp * y**y_exp * z**z_exp)
assert matchRes[x_exp].is_integer and matchRes[y_exp].is_integer and matchRes[z_exp].is_integer
expTuple = (int(matchRes[x_exp]), int(matchRes[y_exp]), int(matchRes[z_exp]),)
if dim < 3:
for i in range(dim, 3):
assert expTuple[i] == 0, "Used symbols in polynomial are not representable in that dimension"
expTuple = expTuple[:dim]
- coeffExpTupleRepresentation.append((coefficient, expTuple))
+ coeffExpTupleRepresentation.append((matchRes[c], expTuple))
return coeffExpTupleRepresentation
--
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