Merge branch 'negatives_in_polynomials'

This commit is contained in:
Hugo Sales 2018-11-23 15:37:24 +00:00
commit 899313cf19
2 changed files with 98 additions and 78 deletions

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@ -26,6 +26,7 @@
* reversing of a predicate. * reversing of a predicate.
*/ */
:- use_module(library(clpfd)). :- use_module(library(clpfd)).
%% :- use_module(library(clpr)).
/******************************* /*******************************
@ -38,21 +39,24 @@
argument) and vice-versa. argument) and vice-versa.
*/ */
poly2list(P, L) :- poly2list(P, L) :-
polynomial_to_list(P, L). polynomial_to_list(P, L),
!.
/* /*
simpolylist/2 simplifies a polynomial represented as a list into simpolylist/2 simplifies a polynomial represented as a list into
another polynomial as a list. another polynomial as a list.
*/ */
simpoly_list(L, S) :- simpoly_list(L, S) :-
simplify_polynomial_list(L, S). simplify_polynomial_as_list(L, S),
!.
/* /*
simpoly/2 simplifies a polynomial represented as an expression simpoly/2 simplifies a polynomial represented as an expression
as another polynomial as an expression. as another polynomial as an expression.
*/ */
simpoly(P, S) :- simpoly(P, S) :-
simplify_polynomial(P, S). simplify_polynomial(P, S),
!.
/* /*
scalepoly/3 multiplies a polynomial represented as an expression by a scalar scalepoly/3 multiplies a polynomial represented as an expression by a scalar
@ -60,7 +64,8 @@ simpoly(P, S) :-
be ground. The polynomial resulting from the sum is in simplified form. be ground. The polynomial resulting from the sum is in simplified form.
*/ */
scalepoly(P1, P2, S) :- scalepoly(P1, P2, S) :-
scale_polynomial(P1, P2, S). scale_polynomial(P1, P2, S),
!.
/* /*
addpoly/3 adds two polynomials as expressions resulting in a addpoly/3 adds two polynomials as expressions resulting in a
@ -68,7 +73,8 @@ scalepoly(P1, P2, S) :-
The polynomial resulting from the sum is in simplified form. The polynomial resulting from the sum is in simplified form.
*/ */
addpoly(P1, P2, S) :- addpoly(P1, P2, S) :-
add_polynomial(P1, P2, S). add_polynomial(P1, P2, S),
!.
/******************************* /*******************************
@ -99,12 +105,13 @@ polynomial_variable(X) :-
% Returns true if X is a power term, false otherwise. % Returns true if X is a power term, false otherwise.
% %
power(P^N) :- power(P^N) :-
( (
zcompare((<), 0, N), N #>= 1,
polynomial_variable(P) %% zcompare((<), -1, N),
; polynomial_variable(P)
fail ;
). fail
).
power(X) :- power(X) :-
polynomial_variable(X). polynomial_variable(X).
%% Tests: %% Tests:
@ -119,12 +126,12 @@ power(X) :-
%% ?- power(x^(-3)). %% ?- power(x^(-3)).
%@ false. %@ false.
%% ?- power(X). %% ?- power(X).
%@ X = x^_7334, %@ X = x^_2420,
%@ _7334 in 1..sup ; %@ _2420 in 0..sup ;
%@ X = y^_7334, %@ X = y^_2420,
%@ _7334 in 1..sup ; %@ _2420 in 0..sup ;
%@ X = z^_7334, %@ X = z^_2420,
%@ _7334 in 1..sup ; %@ _2420 in 0..sup ;
%@ X = x ; %@ X = x ;
%@ X = y ; %@ X = y ;
%@ X = z. %@ X = z.
@ -134,14 +141,19 @@ power(X) :-
% Returns true if N is a term, false otherwise. % Returns true if N is a term, false otherwise.
% %
term(N) :- term(N) :-
number(N). (nonvar(N),
%% N in inf..sup. number(N));
(not(compound(N)),
var(N),
N in inf..sup).
%% {N >= -1000, N =< 1000}.
%% N ::= inf..sup.
%% (var(N), N in inf..sup).
term(X) :- term(X) :-
power(X). power(X).
term(L * R) :- term(L * R) :-
term(L), term(L),
term(R). term(R).
%% append_two_atoms_with_star(L, R, T).
%% Tests: %% Tests:
%% ?- term(2*x^3). %% ?- term(2*x^3).
%@ true . %@ true .
@ -156,9 +168,31 @@ term(L * R) :-
%% ?- term(3.2*x). %% ?- term(3.2*x).
%@ true . %@ true .
%% ?- term(X). %% ?- term(X).
%@ X in inf..sup ;
%@ X = x^_1242,
%@ _1242 in 1..sup ;
%@ X = y^_1242,
%@ _1242 in 1..sup ;
%@ X = z^_1242,
%@ _1242 in 1..sup ;
%@ X = x ;
%@ X = y ;
%@ X = z ;
%@ X = _1330*_1332,
%@ _1330 in inf..sup,
%@ _1332 in inf..sup ;
%@ X = _1406*x^_1414,
%@ _1406 in inf..sup,
%@ _1414 in 1..sup ;
%@ X = _1406*y^_1414,
%@ _1406 in inf..sup,
%@ _1414 in 1..sup ;
%@ X = _1406*z^_1414,
%@ _1406 in inf..sup,
%@ _1414 in 1..sup ;
%@ X = _1188*x,
%@ _1188 in inf..sup .
%% Doesn't give all possible terms, because number(N) is not reversible %% Doesn't give all possible terms, because number(N) is not reversible
%% The ic library seems to be able to help here, but it's not a part of
%% SwiPL by default
%% is_term_valid_in_predicate(+T, +F) is det %% is_term_valid_in_predicate(+T, +F) is det
% %
@ -247,6 +281,8 @@ term_to_list(P, [P2]) :-
%@ X = [1] . %@ X = [1] .
%% ?- term_to_list(-1, X). %% ?- term_to_list(-1, X).
%@ X = [-1] . %@ X = [-1] .
%% ?- term_to_list(2 * 3, X).
%@ X = [3, 2] .
%% ?- term_to_list(1*2*y*z*23*x*y*x^3*x, X). %% ?- term_to_list(1*2*y*z*23*x*y*x^3*x, X).
%@ X = [x^1, x^3, y^1, x^1, 23, z^1, y^1, 2, 1] . %@ X = [x^1, x^3, y^1, x^1, 23, z^1, y^1, 2, 1] .
%% ?- term_to_list(X, [-1]). %% ?- term_to_list(X, [-1]).
@ -343,17 +379,8 @@ simplify_polynomial(0, 0) :-
!. !.
simplify_polynomial(P, P2) :- simplify_polynomial(P, P2) :-
polynomial_to_list(P, L), polynomial_to_list(P, L),
maplist(term_to_list, L, L2), simplify_polynomial_as_list(L, L2),
maplist(sort(0, @>=), L2, L3), polynomial_to_list(P2, L2),
sort(0, @>=, L3, L4),
maplist(join_similar_parts_of_term, L4, L5),
maplist(sort(0, @=<), L5, L6),
join_similar_terms(L6, L7),
maplist(reverse, L7, L8),
maplist(term_to_list, L9, L8),
delete(L9, 0, L10),
sort(0, @=<, L10, L11),
list_to_polynomial(L11, P2),
!. !.
%% Tests: %% Tests:
%% ?- simplify_polynomial(1, X). %% ?- simplify_polynomial(1, X).
@ -454,49 +481,53 @@ add_terms([NL | TL], [NR | TR], [N2 | TL2]) :-
%% ?- add_terms([2, x^3], [3, x^3], R). %% ?- add_terms([2, x^3], [3, x^3], R).
%@ R = [5, x^3]. %@ R = [5, x^3].
%% simplify_polynomial_list(+L:list, -S:list) is det %% simplify_polynomial_as_list(+L1:List,-L3:List) is det
% %
% Simplifies a polynomial represented as a list % Simplifies a polynomial represented as a list
% %
simplify_polynomial_list(L, S) :- simplify_polynomial_as_list(L, L11) :-
polynomial_to_list(P1, L), maplist(term_to_list, L, L2),
simplify_polynomial(P1, P2), maplist(sort(0, @>=), L2, L3),
polynomial_to_list(P2, S). sort(0, @>=, L3, L4),
maplist(join_similar_parts_of_term, L4, L5),
maplist(sort(0, @=<), L5, L6),
join_similar_terms(L6, L7),
maplist(reverse, L7, L8),
maplist(term_to_list, L9, L8),
delete(L9, 0, L10),
sort(0, @=<, L10, L11).
%% polynomial_to_list(+P:polynomial, -L:List) %% polynomial_to_list(+P:polynomial, -L:List) is det
% %
% Converts a polynomial in a list. % Converts a polynomial in a list.
% %
polynomial_to_list(L - T, [T2 | LS]) :- polynomial_to_list(L - T, [T2 | LS]) :-
term(T), term(T),
negate_term(T, T2), negate_term(T, T2),
polynomial_to_list(L, LS). polynomial_to_list(L, LS),
!.
polynomial_to_list(L + T, [T | LS]) :- polynomial_to_list(L + T, [T | LS]) :-
term(T), term(T),
polynomial_to_list(L, LS). polynomial_to_list(L, LS),
!.
polynomial_to_list(T, [T]) :- polynomial_to_list(T, [T]) :-
term(T). term(T),
!.
%% Tests: %% Tests:
%% ?- polynomial_to_list(2, S). %% ?- polynomial_to_list(2, S).
%@ S = [2] . %@ S = [2].
%% ?- polynomial_to_list(x^2, S). %% ?- polynomial_to_list(x^2, S).
%@ S = [x^2] . %@ S = [x^2].
%% ?- polynomial_to_list(x^2 + x^2, S). %% ?- polynomial_to_list(x^2 + x^2, S).
%@ S = [x^2, x^2] . %@ S = [x^2, x^2].
%% ?- polynomial_to_list(2*x^2+5+y*2, S). %% ?- polynomial_to_list(2*x^2+5+y*2, S).
%@ S = [y*2, 5, 2*x^2] . %@ S = [y*2, 5, 2*x^2].
%% ?- polynomial_to_list(2*x^2+5-y*2, S). %% ?- polynomial_to_list(2*x^2+5-y*2, S).
%@ S = [-2*y, 5, 2*x^2] . %@ S = [-2*y, 5, 2*x^2].
%% ?- polynomial_to_list(2*x^2-5-y*2, S). %% ?- polynomial_to_list(2*x^2-5-y*2, S).
%@ S = [-2*y, -5, 2*x^2] . %@ S = [-2*y, -5, 2*x^2].
%% ?- polynomial_to_list(P, [2]). %% ?- polynomial_to_list(2*x^2+3*x+5*x^17-7*x^21+3*x^3-23*x^4+25*x^5-4.3, S).
%@ P = 2 . %@ S = [-4.3, 25*x^5, -23*x^4, 3*x^3, -7*x^21, 5*x^17, 3*x, 2* ... ^ ...].
%% ?- polynomial_to_list(P, [x]).
%@ P = x .
%% ?- polynomial_to_list(P, [x^2, x, 2.3]).
%@ Action (h for help) ? abort
%@ % Execution Aborted
%@ P = -2.3+x+x^2 .
%% list_to_polynomial(+P:polynomial, -L:List) %% list_to_polynomial(+P:polynomial, -L:List)
% %
@ -551,36 +582,23 @@ negate_term(T, T2) :-
%% ?- negate_term(3*x*y^2, R). %% ?- negate_term(3*x*y^2, R).
%@ R = -3*x*y^2. %@ R = -3*x*y^2.
%% append_two_atoms_with_star(+V1, +V2, -R) is det
%
% Returns R = V1 * V2
%
append_two_atoms_with_star(V1, V2, R) :-
% Convert term V2 into a string V3
term_string(V2, V3),
% Concat atom V1 with * into a compound V4
atom_concat(V1, *, V4),
% Concat atom V4 with V3 into a compound S
atom_concat(V4, V3, S),
% Convert compound S into a term R
term_string(R, S).
%% Tests:
% ?- append_two_atoms_with_star(2, x^2, R).
%@ R = 2*x^2.
%@ R = 2*x^2.
%@ R = 2*3.
%% scale_polynomial(+P:polynomial,+C:constant,-S:polynomial) is det %% scale_polynomial(+P:polynomial,+C:constant,-S:polynomial) is det
% %
% Scales a polynomial with a constant % Scales a polynomial with a constant
% %
scale_polynomial(P, C, S) :- scale_polynomial(P, C, S) :-
polynomial_to_list(P, L), polynomial_to_list(P, L),
maplist(append_two_atoms_with_star(C), L, L2), maplist(term_to_list, L, L2),
list_to_polynomial(L2, S). maplist(cons(C), L2, L3),
maplist(term_to_list, L4, L3),
simplify_polynomial_as_list(L4, L5),
list_to_polynomial(L5, S),
!.
%% Tests: %% Tests:
%% ?- scale_polynomial(3*x^2, 2, S). %% ?- scale_polynomial(3*x^2, 2, S).
%@ S = 2*3*x^2. %@ S = 6*x^2.
cons(C, L, [C | L]).
%% add_polynomial(+P1:polynomial,+P2:polynomial,-S:polynomial) is det %% add_polynomial(+P1:polynomial,+P2:polynomial,-S:polynomial) is det
% %

2
test.pl Normal file
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@ -0,0 +1,2 @@
:- use_module(library(clpfd)).
foo(N) :- (nonvar(N), number(N));(var(N), N in inf..sup).