标题: VRP问题的lingo程序(多旅行商问题) [打印本页] 作者: taowenbao 时间: 2012-9-1 15:21
本主题需向作者支付 5 点体力 才能浏览
作者: 王冰清 时间: 2012-9-1 16:28 作者: taowenbao 时间: 2012-9-6 15:55
很好的喔~~~~~~~~~~作者: jiaqing 时间: 2012-10-27 20:18
付钱了。作者: 问安少年 时间: 2012-10-28 20:14
muqian...................作者: 一只想死的鱼 时间: 2012-10-29 08:52
这个模型不是很清晰吧,你应该把模型写出来,可供参考的。表面上看很普通的程序,而多旅行商和VRP有区别的,你这里的约束也不够。。。太少了作者: yinfeng0814 时间: 2012-12-6 18:33
看看楼主的程序,学习学习作者: yinfeng0814 时间: 2012-12-7 10:22
5个体力点对新人来说太贵了啊作者: liyunan220 时间: 2012-12-13 09:23
我下载了 去哪里找啊作者: liyunan220 时间: 2012-12-18 09:13
MODEL: " K1 P) K. c+ S2 ~9 u6 M ) \+ B! t0 u1 A! The Vehicle Routing Problem (VRP); 2 U* V- t$ B( G$ m! R( l( ]
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!************************************; ! p/ i6 ^/ X r/ G. c! WARNING: Runtimes for this model ;9 O! y: {( b! U2 \. I" n4 a. ^ N
! increase dramatically as the number;$ i: w/ ]/ ^. k4 ^3 U8 ^
! of cities increase. Formulations ; 7 m F4 _: F N! j! with more than a dozen cities ;+ K/ w, c, X3 S" k
! WILL NOT SOLVE in a reasonable ; $ p' H% G" P; n* |3 Z& B; A8 U! amount of time! ; 9 U W9 x3 Q' J' _) P+ b9 X- @!************************************; " x" E0 B& \' u+ x0 l! i. m2 p% X) P6 n5 c4 `) O$ [* Z
SETS:6 z0 R' V+ K2 C
! Q(I) is the amount required at city I,+ V E: x; K* ~! C/ C1 W
U(I) is the accumulated delivers at city I ;" Y: R g2 [1 h
CITY/1..8/: Q, U;& T5 Y. M8 j6 v, M0 @3 f
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! DIST(I,J) is the distance from city I to city J . T; Y7 p3 O, _8 U& f5 ] X(I,J) is 0-1 variable: It is 1 if some vehicle5 V( Y5 C* ~9 `4 \2 A6 X
travels from city I to J, 0 if none;9 }: }/ I! i" b0 ^8 S, M2 G1 v9 @
CXC( CITY, CITY): DIST, X;' k3 F8 C7 p' c" z# w
ENDSETS! h5 @2 }6 y/ M
A& [) k- P3 `" H, V x% v DATA:- c. |6 Z' Z3 _' C0 T
! city 1 represent the common depo; ; Z! W) N! P K Q = 0 6 3 7 7 18 4 5;0 g+ @) Z& e2 l' d
4 x; q% Q" Y0 U! Z; X ! distance from city I to city J is same from city4 L& w9 J& q6 [7 X7 J$ T/ ?
J to city I distance from city I to the depot is ; N( U2 `, e) F7 Y" ] 0, since the vehicle has to return to the depot; 7 y$ Y: N. I6 m$ Q; R9 u) ]3 T$ I
DIST = ! To City;% T! C& |" j2 l2 ?
! Chi Den Frsn Hous KC LA Oakl Anah From; / C: W9 A3 a9 Y* v( g( m } 0 996 2162 1067 499 2054 2134 2050!Chicago; 9 t3 K6 h* P- t 0 0 1167 1019 596 1059 1227 1055!Denver; - K9 \4 Q5 `) e& d4 t 0 1167 0 1747 1723 214 168 250!Fresno; 7 i( }5 p x% D$ } 0 1019 1747 0 710 1538 1904 1528!Houston;: H& c0 e1 y. I, ], q: B# g2 e
0 596 1723 710 0 1589 1827 1579!K. City; g* L* s$ |5 n q! ^( S+ B
0 1059 214 1538 1589 0 371 36!L. A.; ) Q5 m: M/ { o/ h+ ? 0 1227 168 1904 1827 371 0 407!Oakland; 3 P0 I6 i% x. y3 T 0 1055 250 1528 1579 36 407 0;!Anaheim;4 b: ~- h' e( o6 u% v: }
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! VCAP is the capacity of a vehicle ;' D% |% z o! u8 G5 {9 c; g! p
VCAP = 18; 6 r* {/ M5 s8 [. B: R e( r3 C ENDDATA " V8 U' ~' y" l4 T+ ~( P5 q $ @! v6 }* D! E& ~( _ ! Minimize total travel distance; 4 T2 ~3 {5 u; i7 E% v" s2 ^ MIN = @SUM( CXC: DIST * X); * y) D r; a5 }' s4 t7 N; b; i6 k' b, X% n; p
! For each city, except depot....;, H3 f: u7 d7 M6 M5 V4 t/ O
@FOR( CITY( K)| K #GT# 1:1 q0 X- J& o V) y
* U5 x/ W8 U! p9 q& P ! a vehicle does not travel inside itself,...; 4 i2 M F9 H8 O7 q9 T X( K, K) = 0;, j! x! p2 S7 M2 u( h
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! a vehicle must enter it,... ;, r. x# z" k# @
@SUM( CITY( I)| I #NE# K #AND# ( I #EQ# 1 #OR# ( Y1 V2 n' f L* B% T Q( I) + Q( K) #LE# VCAP): X( I, K)) = 1;6 `/ j" S" P8 R) H3 i
/ I- I; V. Y" |6 I0 n ! a vehicle must leave it after service ; , E# ^3 O5 \4 T5 f1 h8 x @SUM( CITY( J)| J #NE# K #AND# ( J #EQ# 1 #OR#" @/ V6 ]- R+ K
Q( J) + Q( K) #LE# VCAP): X( K, J)) = 1; ) Y6 o. U @7 C/ B! I " y: w% K) W0 d \5 ~ ! U( K) is at least amount needed at K but can't , ~- B+ y+ I: d/ G% x( i& @; x exceed capacity;/ W7 N2 D- {5 Y* ?, ~9 ~; T
@BND( Q( K), U( K), VCAP);7 H. ]7 {- b: Q" a: k n: U$ i
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! If K follows I, then can bound U( K) - U( I); / V& k$ Z# p; \# X- o, X @FOR( CITY( I)| I #NE# K #AND# I #NE# 1: 2 A! [2 ]. l! K( q+ m: A W% ^0 Z. @ U( K) >= U( I) + Q( K) - VCAP + VCAP * 0 S' m) J, G) j( }. b/ F% r7 j
( X( K, I) + X( I, K)) - ( Q( K) + Q( I))+ g* y" Q. Y- c1 F; J$ Y! V
* X( K, I); v' }8 k0 q! `3 ~" z4 Q4 ` );' g# a( Z! W9 a4 Z( o
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! If K is 1st stop, then U( K) = Q( K);8 \8 H7 h( [* m/ c, M Z" Q+ c
U( K) <= VCAP - ( VCAP - Q( K)) * X( 1, K);( P; b/ {/ d) \+ p* {2 `