Using (nb_)setarg/3 with gnu.prolog in Java -


i'm trying use prolog out of java using gnu.prolog (http://www.gnu.org/software/gnuprologjava/).

thanks great of capellic have prolog program works perfect purpose. problem gnu.prolog not support reverse/2 nor support nb_setarg/3. java throw error:

exception in thread "game" java.lang.illegalargumentexception: goal not active

it isn't big issue implement reverse/2 on own have no idea how replace nb_setarg/3 (setarg/3 doesn't work)

here prolog code:

findpath(_limit, [goal | rest], goal, temp, temp, [goal | rest]) :- !.  findpath(limit, [a | rest], goal, cost, temp, path) :-     path(a,b,c),     \+member(b, rest),     newcosts (temp + c),     newcosts < limit,     findpath(limit, [b, | rest], goal, cost, newcosts, path).  searchpath(start, goal, path_to_goal) :-     s = path_len([], 50),     repeat,     arg(2, s, limit),     (   findpath(limit, [start], goal, cost, 0, path)     ->  (   cost < limit         ->  nb_setarg(1, s, path),         nb_setarg(2, s, cost),         fail         )     ;   true     ),     arg(1, s, rev),     reverse(rev, path_to_goal).

i tried use jpl swi prolog wasn't able run because of severel exceptions pointing out, eclipse wasn't able find library correctly. 1 of following exceptions:

exception in thread "main" java.lang.unsatisfiedlinkerror: no jpl in java.library.path   unsatisfiedlinkerror: d:\program files\prolog\bin\jpl.dll: can't find dependent libraries  swi-prolog: [fatal error:     not find system resources]

even after following this , this guide wasn't able resolve problems. neither on windows (32bit) nor on ubuntu (64bit).

do have solutions me how can either jpl running or how able use nb_setarg/3? spent 1 , half days without results. quite frustrating...

i'm sorry, suggestion use gprolog setarg replacement swi-prolog nb_setarg wrong. reworked code in simpler , (i hope) more effective way, working under iso prolog.

% data original prolog dijkstra' algorithm implementation :- initialization( consult(salesman) ).  :- dynamic(best_so_far/2).  path(x,y,z) :- dist(x, y, z). path(x,y,z) :- dist(y, x, z).  findpath([goal | rest], goal, temp, temp, [goal | rest]) :-     !. findpath([a | rest], goal, cost, temp, path) :-     path(a, b, c),     \+ member(b, rest),     newcost temp + c,     best_so_far(limit, _),     newcost < limit,     findpath([b, | rest], goal, cost, newcost, path).  % ?- searchpath(aberdeen, glasgow, l, p). % searchpath(start, goal, bestlen, bestpath) :-     retractall(best_so_far(_, _)),     asserta(best_so_far(1000000, [])),     findpath([start], goal, cost, 0, path),     % if here, it's because lower cost exists     retractall(best_so_far(_, _)),     asserta(best_so_far(cost, path)),     fail     ;     best_so_far(bestlen, bestpath).

if want fasten bit, there simple heuristic should applicable: namely make findpath greedy, selecting first lower cost branchs. can done setof+member...


Comments

Post a Comment

Popular posts from this blog

monitor web browser programmatically in Android? -

i've got tricky question here. need users make payment bank (namely barclaycard) in uk. so, have https url , add parameters (such amount pay, order reference, etc) url, start http connection intent.actionview, redirect user browser can enter credit card details on bank's webpage , make payment our account successfully. far ? the code use below (i changed values privacy reasons) problem is, need app when user has completed/failed/cancelled payment. barclaycardautomatically redirects particular url when payment has succeeded, 1 if failed. there no way of knowing when barclaycard payment has succeeded go android app somehow ? button cardbutton = (button) findviewbyid(r.id.card_button); cardbutton.setonclicklistener(new view.onclicklistener() { @override public void onclick(view arg0) { string prehashstring = new string(); string prohashstring = new string(); string shapassphrase = new string(); shapassphrase = "gsvth£h70zkh...
Read more

Shrink a YouTube video to responsive width -

i have youtube video embedded on our website , when shrink screen tablet or phone sizes stops shrinking @ around 560px in width. standard youtube videos or there can add code make go smaller? you can make youtube videos responsive css. wrap iframe in div class of "videowrapper" , apply following styles: .videowrapper { float: none; clear: both; width: 100%; position: relative; padding-bottom: 56.25%; padding-top: 25px; height: 0; } .videowrapper iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; } the .videowrapper div should inside responsive element. padding on .videowrapper necessary keep video collapsing. may have tweak numbers depending upon layout.
Read more

wpf - PdfWriter.GetInstance throws System.NullReferenceException -

i'm trying create pdf document using itextsharp 5.3.4 using following document document = new document(); filestream stm = new filestream(filename, filemode.create); pdfwriter writer = pdfwriter.getinstance(document, stm); i'm getting system.nullreferenceexception following stack trace: system.nullreferenceexception occurred hresult=-2147467261 message=la référence d'objet n'est pas définie à une instance d'un objet. source=itextsharp stacktrace: à itextsharp.text.version.getinstance() innerexception: i've verified neither document nor stm null, , if select "continue" in vs12 document created - exception thrown. updated itextsharp 5.4.0 , it's still occurring. can't find information on anywhere - got ideas? make sure not catching exceptions. nullreferenceexception can 1 caught , handled inside itextsharp, don't care it. fact can continue supports theory. change following setting verify: debug -> exceptions ...
Read more