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Dictionary convolution

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lafrite 2014-01-18 16:42:03 +01:00
parent 039f27c4fc
commit 12b29be0d9
1 changed files with 36 additions and 0 deletions
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36
generic.py
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@ -143,6 +143,42 @@ def remove_in_dict(d, value = 0):
new_dict[k] = v
return new_dict
def convolution_dict(D1, D2, op = lambda x,y:x*y,\
commutative = True, op_twice = lambda x,y: x + y):
"""Convolution of two dictionaries
:param D1: First dictionary
:param D2: Second dictionary
:param op: Operation of perform in value
:param commutative: keys are commutative?
:param op_twice: operation on value if the key appear twice
>>> convolution_dict({"a": 1, "b":3}, {"a":2, "":4}) == {"aa":2, "a": 4, "ba":6, "b":12}
True
>>> convolution_dict({"a": 1, "b":3}, {"a":2, "b":4}) == {"aa":2, "ab":10, "bb":12}
True
>>> convolution_dict({"a": 1, "b":3}, {"a":2, "b":4}, commutative = False) == {"aa":2, "ab":10, "bb":12}
False
>>> convolution_dict({"a": 1, "b":3}, {"a":2, "b":4}, commutative = False) == {"aa":2, "ab":4,"ba":6, "bb":12}
True
>>> convolution_dict({"a": 1, "b":3}, {"a":2, "b":4}, \
op_twice = lambda x,y:[x,y]) == {"aa":2, "ab":[4,6], "bb":12}
True
"""
new_dict = {}
for k1 in sorted(D1.keys()):
for k2 in sorted(D2.keys()):
if k1+k2 in new_dict.keys():
new_dict[k1+k2] = op_twice(new_dict[k1+k2], op(D1[k1],D2[k2]))
elif k2+k1 in new_dict.keys() and commutative:
new_dict[k2+k1] = op_twice(new_dict[k2+k1], op(D1[k1],D2[k2]))
else:
new_dict[k1+k2] = op(D1[k1],D2[k2])
return new_dict
if __name__ == '__main__':
import doctest
doctest.testmod()