Jip J. Dekker
b5f0d64642
git-subtree-dir: prototype git-subtree-split: 91f7db00d45e7f991b5587ee07f09977ae311ee7
68 lines
1.7 KiB
MiniZinc
68 lines
1.7 KiB
MiniZinc
% RUNS ON mzn20_fd
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% RUNS ON mzn-fzn_fd
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% RUNS ON mzn20_fd_linear
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% RUNS ON mzn20_mip
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%
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% Constraint Programming: Mortgage
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%
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%
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% This Minizinc program is written by Hakan Kjellerstrand, hakank@bonetmail.com,
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% and is commented in the (swedish) blog post
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% Constraint Programming: Minizinc, Gecode/flatzinc och ECLiPSe/minizinc
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% http://www.hakank.org/webblogg/archives/001209.html
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%
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% See also my MiniZinc page: http://www.hakank.org/minizinc
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%
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% Marriot & Stuckey: Programming with Constraints, page 175f
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% (famous early example)
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%
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% Since Minizinc don't allow recursion, it is implemented as an array.
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%
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% This example shows the flexibility of Minizinc:
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% the same code can calculate P, R _or_ I with just a simple change of the declarations.
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%
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%
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% Calculates P, given I and R:
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% P: 373.02779864763335
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%
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% Calculates R, given P and I:
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% R: 149.944102252456 (which is close to 150)
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%
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% Calculates I, given R and P:
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% I: 0.099995922287248337__0.10000424331679297 (close to 0.1)
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% Note: As of 2008-06-23 this don't work in version >= 0.8.
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% It may work with later version, though.
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int: T = 3; % time period
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% comment one of the initiations to calculate it:
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var 0.0..10000.0: I = 10.0/100.0;
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var 0.0..10000.0: R = 150.0;
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var 0.0..10000.0: P; % = 373.02779864763318;
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array[1..T] of var float: mortgage;
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solve satisfy;
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% solve minimize P;
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constraint
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% start value:
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mortgage[1] = P + (P * I) - R /\
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forall(i in 2..T) (
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% calculate the next value using a local variable
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let {
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var float: NP = mortgage[i-1] + (mortgage[i-1] * I) - R
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}
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in
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mortgage[i] = NP /\ NP >= 0.0
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)
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;
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output [
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"P: ", show(P), "\n",
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"I: ", show(I), "\n",
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"R: ", show(R), "\n",
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"mortgage: ", show(mortgage),"\n" % is not especially interesting
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];
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