Re: Python: How to find out values of all feasible x under constraints.
On 15/05/2015 13:35, Mark Lawrence wrote: On 15/05/2015 04:58, Xiang Zhang wrote: Dear all, I am writing a code using Python now. I want to know how to find out values of all feasible x under constraints. x = [x_1, x_2, x_3,..., x_10] constraints: x_i = 0,1,2,3 or 4, where i=1,2,10 x_1 + x_2 + x_3 +...+x_10 <= 15 How to find out all the feasible solutions x (domain of x) using python, like [0,0,0,0,0,0,0,0,0,0], [1,1,1,1,1,1,1,1,1,1] etc ? What should be the code? Any hint or help would be highly appreciated! Sincerely, Xiang Zhang There are several constraint libraries on pypi if you don't want to roll your own. See for example https://pypi.python.org/pypi/python-constraint/1.2 Forgot to mention this http://numberjack.ucc.ie/ Maybe of general interest see also http://www.csplib.org/ http://www.hakank.org/constraint_programming_blog/ -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence -- https://mail.python.org/mailman/listinfo/python-list
Re: Python: How to find out values of all feasible x under constraints.
On 15/05/2015 04:58, Xiang Zhang wrote: Dear all, I am writing a code using Python now. I want to know how to find out values of all feasible x under constraints. x = [x_1, x_2, x_3,..., x_10] constraints: x_i = 0,1,2,3 or 4, where i=1,2,10 x_1 + x_2 + x_3 +...+x_10 <= 15 How to find out all the feasible solutions x (domain of x) using python, like [0,0,0,0,0,0,0,0,0,0], [1,1,1,1,1,1,1,1,1,1] etc ? What should be the code? Any hint or help would be highly appreciated! Sincerely, Xiang Zhang There are several constraint libraries on pypi if you don't want to roll your own. See for example https://pypi.python.org/pypi/python-constraint/1.2 -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence -- https://mail.python.org/mailman/listinfo/python-list
Re: Python: How to find out values of all feasible x under constraints.
Xiang Zhang wrote: > I want to know how to find out values of all feasible x under constraints. > > x = [x_1, x_2, x_3,..., x_10] > > > constraints: > x_i = 0,1,2,3 or 4, where i=1,2,10 > x_1 + x_2 + x_3 +...+x_10 <= 15 That are 5**10 == 9765625 candidates. That's still feasible to check using brute force. > How to find out all the feasible solutions x (domain of x) using python, > like [0,0,0,0,0,0,0,0,0,0], [1,1,1,1,1,1,1,1,1,1] etc ? What should be the > code? > > Any hint or help would be highly appreciated! >>> solutions = [x for x in itertools.product(range(5), repeat=10) if sum(x) <= 15] >>> len(solutions) 1556215 The first ten solutions: >>> solutions[:10] [(0, 0, 0, 0, 0, 0, 0, 0, 0, 0), (0, 0, 0, 0, 0, 0, 0, 0, 0, 1), (0, 0, 0, 0, 0, 0, 0, 0, 0, 2), (0, 0, 0, 0, 0, 0, 0, 0, 0, 3), (0, 0, 0, 0, 0, 0, 0, 0, 0, 4), (0, 0, 0, 0, 0, 0, 0, 0, 1, 0), (0, 0, 0, 0, 0, 0, 0, 0, 1, 1), (0, 0, 0, 0, 0, 0, 0, 0, 1, 2), (0, 0, 0, 0, 0, 0, 0, 0, 1, 3), (0, 0, 0, 0, 0, 0, 0, 0, 1, 4)] -- https://mail.python.org/mailman/listinfo/python-list
Python: How to find out values of all feasible x under constraints.
Dear all, I am writing a code using Python now. I want to know how to find out values of all feasible x under constraints. x = [x_1, x_2, x_3,..., x_10] constraints: x_i = 0,1,2,3 or 4, where i=1,2,10 x_1 + x_2 + x_3 +...+x_10 <= 15 How to find out all the feasible solutions x (domain of x) using python, like [0,0,0,0,0,0,0,0,0,0], [1,1,1,1,1,1,1,1,1,1] etc ? What should be the code? Any hint or help would be highly appreciated! Sincerely, Xiang Zhang -- https://mail.python.org/mailman/listinfo/python-list
