54 lines
1.6 KiB
Python
54 lines
1.6 KiB
Python
#!/usr/bin/env python3
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r"""
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This package contains calculations of signature functions for knots (cable sums)
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It can be run as a sage script from the terminal or used in interactive mode.
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A knot (cable sum) is encoded as a list where each element (also a list)
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corresponds to a cable knot, e.g. a list
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[[1, 3], [2], [-1, -2], [-3]] encodes
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T(2, 3; 2, 7) # T(2, 5) # -T(2, 3; 2, 5) # -T(2, 7).
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To calculate the number of characters for which signature function vanish use
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the function .
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sage: eval_cable_for_null_signature([[1, 3], [2], [-1, -2], [-3]])
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T(2, 3; 2, 7) # T(2, 5) # -T(2, 3; 2, 5) # -T(2, 7)
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Zero cases: 1
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All cases: 1225
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Zero theta combinations:
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(0, 0, 0, 0)
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sage:
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The numbers given to the function eval_cable_for_null_signature are k-values
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for each component/cable in a direct sum.
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To calculate signature function for a knot and a theta value, use function
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get_signature_as_function_of_theta (see help/docstring for details).
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About notation:
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Cables that we work with follow a schema:
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T(2, q_1; 2, q_2; 2, q_4) # -T(2, q_2; 2, q_4) #
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# T(2, q_3; 2, q_4) # -T(2, q_1; 2, q_3; 2, q_4)
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In knot_formula each k[i] is related with some q_i value, where
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q_i = 2*k[i] + 1.
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So we can work in the following steps:
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1) choose a schema/formula by changing the value of knot_formula
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2) set each q_i all or choose range in which q_i should varry
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3) choose vector v / theata vector.
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"""
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from .utility import import_sage
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import os
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package = __name__.split('.')[0]
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path = os.path.dirname(__file__)
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import_sage('signature', package=package, path=path)
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# import_sage('cable_signature', package=package, path=path)
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# import_sage('main', package=package, path=path)
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