improvements

main
Matthew Butterick 10 years ago
parent 260f934c55
commit b6102f22ee

@ -55,7 +55,7 @@
[_variables (make-hash)]) [_variables (make-hash)])
(define (repr) (format "<Problem ~v>" _variables)) (define (repr) (format "<Problem ~a>" (hash-keys _variables)))
(define/public (custom-print out quoting-depth) (print (repr) out)) (define/public (custom-print out quoting-depth) (print (repr) out))
(define/public (custom-display out) (displayln (repr) out)) (define/public (custom-display out) (displayln (repr) out))
(define/public (custom-write out) (write (repr) out)) (define/public (custom-write out) (write (repr) out))
@ -270,19 +270,18 @@
(define return-result #t) (define return-result #t)
(define unassignedvariable _unassigned) (define unassignedvariable _unassigned)
(report assignments) ;(report assignments)
(let/ec break (let/ec break
(for ([variable (in-list (report variables))]) (for ([variable (in-list variables)])
(when (not (variable . in? . assignments)) (when (not (variable . in? . assignments))
(if (equal? unassignedvariable _unassigned) (if (equal? unassignedvariable _unassigned)
(begin (displayln "boom") (set! unassignedvariable variable)
(set! unassignedvariable variable))
(break)))) (break))))
(when (not (equal? unassignedvariable _unassigned)) (when (not (equal? unassignedvariable _unassigned))
;; Remove from the unassigned variable domain's all ;; Remove from the unassigned variable domain's all
;; values which break our variable's constraints. ;; values which break our variable's constraints.
(define domain (hash-ref domains unassignedvariable)) (define domain (hash-ref domains unassignedvariable))
(report domain domain-fc) ;(report domain domain-fc)
(when (not (null? (get-field _list domain))) (when (not (null? (get-field _list domain)))
(for ([value (in-list (get-field _list domain))]) (for ([value (in-list (get-field _list domain))])
(hash-set! assignments unassignedvariable value) (hash-set! assignments unassignedvariable value)
@ -304,22 +303,20 @@
(field [_func func][_assigned assigned]) (field [_func func][_assigned assigned])
(inherit forwardCheck) (inherit forwardCheck)
(define/override (call variables domains assignments [forwardcheck #f] [_unassigned Unassigned]) (define/override (call variables domains assignments [forwardcheck #f] [_unassigned Unassigned])1
(displayln "in call") ;(report assignments assignments-before)
(report assignments assignments-before)
(define parms (for/list ([x (in-list variables)]) (define parms (for/list ([x (in-list variables)])
(if (hash-has-key? assignments x) (hash-ref assignments x) _unassigned))) (if (hash-has-key? assignments x) (hash-ref assignments x) _unassigned)))
(report assignments assignments-after) ;(report assignments assignments-after)
(define missing (length (filter (λ(v) (equal? v _unassigned)) parms))) (define missing (length (filter (λ(v) (equal? v _unassigned)) parms)))
(displayln "dang")
(if (> missing 0) (if (> missing 0)
(begin (begin
(report missing) ;(report missing)
(report _assigned) ;(report _assigned)
(report parms) ;(report parms)
(report (apply _func parms)) ;(report (apply _func parms))
(report forwardcheck) ;(report forwardcheck)
(report assignments assignments-to-fc) ;(report assignments assignments-to-fc)
(and (or _assigned (apply _func parms)) (and (or _assigned (apply _func parms))
(or (not forwardcheck) (not (= missing 1)) (or (not forwardcheck) (not (= missing 1))
(forwardCheck variables domains assignments)))) (forwardCheck variables domains assignments))))
@ -333,7 +330,6 @@
;; Variables ;; Variables
;; ---------------------------------------------------------------------- ;; ----------------------------------------------------------------------
(define Variable (define Variable
(class* object% (printable<%>) (class* object% (printable<%>)
(super-new) (super-new)
@ -381,7 +377,7 @@
(let/ec break-loop1 (let/ec break-loop1
(set! return-k break-loop1) (set! return-k break-loop1)
(let loop1 () (let loop1 ()
(displayln "starting while loop 1") ;(displayln "starting while loop 1")
;; Mix the Degree and Minimum Remaing Values (MRV) heuristics ;; Mix the Degree and Minimum Remaing Values (MRV) heuristics
@ -389,14 +385,14 @@
(list (* -1 (length (hash-ref vconstraints variable))) (list (* -1 (length (hash-ref vconstraints variable)))
(length (get-field _list (hash-ref domains variable))) (length (get-field _list (hash-ref domains variable)))
variable)) list-comparator)) variable)) list-comparator))
(report lst) ;(report lst)
(let/ec break-for-loop (let/ec break-for-loop
(for ([item (in-list lst)]) (for ([item (in-list lst)])
(when (not ((last item) . in? . assignments)) (when (not ((last item) . in? . assignments))
; Found unassigned variable ; Found unassigned variable
(set! variable (last item)) (set! variable (last item))
(report variable unassigned-variable) ;(report variable unassigned-variable)
(set! values (send (hash-ref domains variable) copy)) (set! values (send (hash-ref domains variable) copy))
(set! pushdomains (set! pushdomains
(if forwardcheck (if forwardcheck
@ -421,15 +417,15 @@
(for ([domain (in-list pushdomains)]) (for ([domain (in-list pushdomains)])
(send domain popState))) (send domain popState)))
(report variable variable-preloop-2) ;(report variable variable-preloop-2)
(report assignments assignments-preloop-2) ;(report assignments assignments-preloop-2)
(let/ec break-loop2 (let/ec break-loop2
(let loop2 () (let loop2 ()
(displayln "starting while loop 2") ;(displayln "starting while loop 2")
;; We have a variable. Do we have any values left? ;; We have a variable. Do we have any values left?
(report values values-tested) ;(report values values-tested)
(when (null? (get-field _list values)) (when (null? (get-field _list values))
;; No. Go back to last variable, if there's one. ;; No. Go back to last variable, if there's one.
@ -457,20 +453,21 @@
(for ([domain (in-list pushdomains)]) (for ([domain (in-list pushdomains)])
(send domain pushState)) (send domain pushState))
(report pushdomains pushdomains1) ;(report pushdomains pushdomains1)
(report domains domains1) ;(report domains domains1)
(let/ec break-for-loop (let/ec break-for-loop
(for ([cvpair (in-list (hash-ref vconstraints variable))]) (for ([cvpair (in-list (hash-ref vconstraints variable))])
(match-define (cons constraint variables) cvpair) (match-define (cons constraint variables) cvpair)
(define the_result (send constraint call variables domains assignments pushdomains)) (define the_result (send constraint call variables domains assignments pushdomains))
(report pushdomains pushdomains2) ;(report pushdomains pushdomains2)
(report domains domains2) ;(report domains domains2)
(report the_result) ;(report the_result)
(when (not the_result) (when (not the_result)
;; Value is not good. ;; Value is not good.
(break-for-loop))) (break-for-loop)))
(begin (displayln "now breaking loop 2") (break-loop2))) (begin ;(displayln "now breaking loop 2")
(break-loop2)))
(for ([domain (in-list pushdomains)]) (for ([domain (in-list pushdomains)])
(send domain popState)) (send domain popState))
@ -479,7 +476,7 @@
;; Push state before looking for next variable. ;; Push state before looking for next variable.
(py-append! queue (list variable (get-field _list (send values copy)) pushdomains)) (py-append! queue (list variable (get-field _list (send values copy)) pushdomains))
(report queue new-queue) ;(report queue new-queue)
(loop1))) (loop1)))
(if want-to-return (if want-to-return
@ -502,14 +499,15 @@
(module+ main (module+ main
(define problem (new Problem)) (define problem (new Problem))
(send problem addVariables '("a" "b") '(1 2 3 4)) (send problem addVariables '("a" "b" "c") (range 1 10))
(define (func a b) ; (send problem addConstraint (λ(a b) (and (> a 0) (= b (* 211 a)))) '("a" "b"))
(cond
[(and (real? b) (real? a)) (> b a)]
[(Variable? b) #t]
[else #f]))
(send problem addConstraint func '("a" "b"))
(displayln (format "The solution to ~a is ~a" (displayln (format "The solution to ~a is ~a"
problem problem
(send problem getSolutions))) (argmin (λ(h)
) (let ([a (hash-ref h "a")]
[b (hash-ref h "b")]
[c (hash-ref h "c")])
(/ (+ (* 100 a) (* 10 b) c) (+ a b c))))
(send problem getSolutions)))))

@ -376,7 +376,7 @@ class Solver(object):
constraints affecting the given variables. constraints affecting the given variables.
@type vconstraints: dict @type vconstraints: dict
""" """
raise NotImplementedError, \ NotImplementedError, \
"%s is an abstract class" % self.__class__.__name__ "%s is an abstract class" % self.__class__.__name__
def getSolutions(self, domains, constraints, vconstraints): def getSolutions(self, domains, constraints, vconstraints):
@ -456,18 +456,18 @@ class BacktrackingSolver(Solver):
queue = [] queue = []
while True: while True:
print "starting while loop 1" #print "starting while loop 1"
# Mix the Degree and Minimum Remaing Values (MRV) heuristics # Mix the Degree and Minimum Remaing Values (MRV) heuristics
lst = [(-len(vconstraints[variable]), lst = [(-len(vconstraints[variable]),
len(domains[variable]), variable) for variable in domains] len(domains[variable]), variable) for variable in domains]
lst.sort() lst.sort()
print "lst", lst #print "lst", lst
for item in lst: for item in lst:
if item[-1] not in assignments: if item[-1] not in assignments:
# Found unassigned variable # Found unassigned variable
variable = item[-1] variable = item[-1]
print "unassigned variable", variable #print "unassigned variable", variable
values = domains[variable][:] values = domains[variable][:]
if forwardcheck: if forwardcheck:
pushdomains = [domains[x] for x in domains pushdomains = [domains[x] for x in domains
@ -479,10 +479,10 @@ class BacktrackingSolver(Solver):
else: else:
# No unassigned variables. We've got a solution. Go back # No unassigned variables. We've got a solution. Go back
# to last variable, if there's one. # to last variable, if there's one.
print "solution time" #print "solution time"
print "solution assignments", assignments #print "solution assignments", assignments
yield assignments.copy() yield assignments.copy()
print "queue", queue #print "queue", queue
if not queue: if not queue:
return return
variable, values, pushdomains = queue.pop() variable, values, pushdomains = queue.pop()
@ -490,12 +490,12 @@ class BacktrackingSolver(Solver):
for domain in pushdomains: for domain in pushdomains:
domain.popState() domain.popState()
print "variable-preloop-2", variable #print "variable-preloop-2", variable
print "assignments-preloop-2", assignments #print "assignments-preloop-2", assignments
while True: while True:
print "starting while loop 2" #print "starting while loop 2"
# We have a variable. Do we have any values left? # We have a variable. Do we have any values left?
print "values tested", values #print "values tested", values
if not values: if not values:
# No. Go back to last variable, if there's one. # No. Go back to last variable, if there's one.
del assignments[variable] del assignments[variable]
@ -516,21 +516,20 @@ class BacktrackingSolver(Solver):
if pushdomains: if pushdomains:
for domain in pushdomains: for domain in pushdomains:
domain.pushState() domain.pushState()
print "pushdomains1", pushdomains #print "pushdomains1", pushdomains
print "domains1", domains #print "domains1", domains
for constraint, variables in vconstraints[variable]: for constraint, variables in vconstraints[variable]:
the_result = constraint(variables, domains, assignments, the_result = constraint(variables, domains, assignments,
pushdomains) pushdomains)
print "pushdomains2", pushdomains #print "pushdomains2", pushdomains
print "domains2", domains #print "domains2", domains
print "the_result", the_result #print "the_result", the_result
raise KeyError("stop")
if not the_result: if not the_result:
# Value is not good. # Value is not good.
break break
else: else:
print "now breaking loop 2" #print "now breaking loop 2"
break break
if pushdomains: if pushdomains:
@ -539,7 +538,7 @@ class BacktrackingSolver(Solver):
# Push state before looking for next variable. # Push state before looking for next variable.
queue.append((variable, values, pushdomains)) queue.append((variable, values, pushdomains))
print "new queue", queue #print "new queue", queue
raise RuntimeError, "Can't happen" raise RuntimeError, "Can't happen"
@ -899,11 +898,11 @@ class Constraint(object):
@rtype: bool @rtype: bool
"""#""" """#"""
unassignedvariable = _unassigned unassignedvariable = _unassigned
print "assignments", assignments #print "assignments", assignments
for variable in variables: for variable in variables:
if variable not in assignments: if variable not in assignments:
if unassignedvariable is _unassigned: if unassignedvariable is _unassigned:
print "boom" #print "boom"
unassignedvariable = variable unassignedvariable = variable
else: else:
break break
@ -912,7 +911,7 @@ class Constraint(object):
# Remove from the unassigned variable domain's all # Remove from the unassigned variable domain's all
# values which break our variable's constraints. # values which break our variable's constraints.
domain = domains[unassignedvariable] domain = domains[unassignedvariable]
print "domain-fc", domain #print "domain-fc", domain
if domain: if domain:
for value in domain[:]: for value in domain[:]:
assignments[unassignedvariable] = value assignments[unassignedvariable] = value
@ -959,19 +958,19 @@ class FunctionConstraint(Constraint):
def __call__(self, variables, domains, assignments, forwardcheck=False, def __call__(self, variables, domains, assignments, forwardcheck=False,
_unassigned=Unassigned): _unassigned=Unassigned):
print "in call" #print "in call"
print "assignments-before", assignments #print "assignments-before", assignments
parms = [assignments.get(x, _unassigned) for x in variables] parms = [assignments.get(x, _unassigned) for x in variables]
print "assignments-after", assignments #print "assignments-after", assignments
missing = parms.count(_unassigned) missing = parms.count(_unassigned)
print "dang" #print "dang"
if missing: if missing:
print "missing", missing #print "missing", missing
print "self._assigned", self._assigned #print "self._assigned", self._assigned
print "parms", parms #print "parms", parms
print "self._func(*parms)", self._func(*parms) #print "self._func(*parms)", self._func(*parms)
print "forwardcheck", forwardcheck #print "forwardcheck", forwardcheck
print "assignments-to-fc", assignments #print "assignments-to-fc", assignments
return ((self._assigned or self._func(*parms)) and return ((self._assigned or self._func(*parms)) and
(not forwardcheck or missing != 1 or (not forwardcheck or missing != 1 or
self.forwardCheck(variables, domains, assignments))) self.forwardCheck(variables, domains, assignments)))

@ -13,7 +13,7 @@ from constraint import *
def main(): def main():
problem = Problem() problem = Problem()
problem.addVariables("abc", range(1,10)) problem.addVariables("abc", range(1,10))
problem.getSolutions() print min(problem.getSolutions())
minvalue = 999/(9*3) minvalue = 999/(9*3)
minsolution = {} minsolution = {}
for solution in problem.getSolutions(): for solution in problem.getSolutions():

@ -8,8 +8,8 @@ from constraint import *
#print p.getSolutions() #print p.getSolutions()
problem = Problem() problem = Problem()
problem.addVariables(["a", "b"], [1, 2]) problem.addVariables(["a", "b"], range(500))
def func(a, b): def func(a, b):
return b > a return a > 0 and b == 211 * a
problem.addConstraint(func, ["a", "b"]) problem.addConstraint(func, ["a", "b"])
problem.getSolution() print problem.getSolutions()

@ -13,18 +13,17 @@ from constraint import *
def main(): def main():
problem = Problem() problem = Problem()
problem.addVariables("abc", range(1,10)) problem.addVariables("abc", range(1,10))
problem.getSolutions() results = []
minvalue = 999/(9*3) for solution in problem.getSolutions():
minsolution = {}
for solution in problem.getSolutions():
a = solution["a"] a = solution["a"]
b = solution["b"] b = solution["b"]
c = solution["c"] c = solution["c"]
value = (a*100+b*10+c)/(a+b+c) results.append((((a*100) + (b*10) + c) / (a + b + c + 0.0), (a*100) + (b*10) + c))
if value < minvalue:
minsolution = solution results.sort()
print (minsolution["a"]*100+minsolution["b"]*10+minsolution["c"])/(minsolution["a"]+minsolution["b"]+minsolution["c"])
print minsolution print results[0]
if __name__ == "__main__": if __name__ == "__main__":
main() main()

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