VRP问题的lingo程序（多旅行商问题）

王冰清

taowenbao

很好的喔~~~~~~~~~~

jiaqing

付钱了。

问安少年

muqian...................

一只想死的鱼

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

yinfeng0814

看看楼主的程序，学习学习

yinfeng0814

5个体力点对新人来说太贵了啊

liyunan220

我下载了 去哪里找啊

liyunan220

MODEL:
6 J2 F* H) D$ M1 g& j, n7 I
* M- h0 O9 W$ s. d, [- z- ^! The Vehicle Routing Problem (VRP);

!************************************;
% n" U5 c  E/ N% Z4 D# _! WARNING: Runtimes for this model   ;
. Z0 f6 Q3 O7 E/ M  K7 n/ _  [! increase dramatically as the number;
! of cities increase. Formulations   ;
! with more than a dozen cities      ;
) Y* r$ @, L6 k# x1 Q7 [' D3 I( {! WILL NOT SOLVE in a reasonable     ;
! amount of time!                    ;
!************************************;

# B& q) R0 R2 A- {4 g SETS:
2 i9 S% n1 G" s) T  ! Q(I) is the amount required at city I,
    U(I) is the accumulated delivers at city I ;
   CITY/1..8/: Q, U;

  ! DIST(I,J) is the distance from city I to city J
# X% ?5 R% n( K7 v    X(I,J) is 0-1 variable: It is 1 if some vehicle
: ]6 a2 v3 M" U; L    travels from city I to J, 0 if none;
. H* K1 N  ^+ Y5 Q   CXC( CITY, CITY): DIST, X;
ENDSETS

DATA:
' G! K! ^+ d6 {& q1 t  ! city 1 represent the common depo;
   Q  =  0    6    3    7    7   18    4    5;
, r! U/ W# [: O! `- A  @' e  P
- v  }: _6 a' o% T/ _  ! distance from city I to city J is same from city
+ u: ]" {$ D' _7 s0 ?! U    J to city I distance from city I to the depot is
5 `6 ]( p# m3 h* @    0, since the vehicle has to return to the depot;
% t' [+ K3 p+ p. e2 @
5 @3 }9 E' _# v! }5 k  }   DIST =  ! To City;
  ! Chi  Den Frsn Hous   KC   LA Oakl Anah   From;
      0  996 2162 1067  499 2054 2134 2050!Chicago;
      0    0 1167 1019  596 1059 1227 1055!Denver;
' T1 \* j1 @0 i0 [3 I      0 1167    0 1747 1723  214  168  250!Fresno;
      0 1019 1747    0  710 1538 1904 1528!Houston;
6 S1 d& Y5 |2 C" n$ p0 O- M7 V      0  596 1723  710    0 1589 1827 1579!K. City;
* @* R% W) [" ]& L0 K# V      0 1059  214 1538 1589    0  371   36!L. A.;
      0 1227  168 1904 1827  371    0  407!Oakland;
6 p- Q! K" o& w% h* _2 X- C: u( M8 C      0 1055  250 1528 1579   36  407    0;!Anaheim;
% J& h6 H2 o/ L
" e) ^) l# |5 _2 V; @  ! VCAP is the capacity of a vehicle ;
! L/ Z; A. h* u+ G* C( W4 g   VCAP = 18;
% t+ o& V4 _. a; z ENDDATA

  ! Minimize total travel distance;
   MIN = @SUM( CXC: DIST * X);
6 e- X. R' ]/ p6 a9 g
  ! For each city, except depot....;
   @FOR( CITY( K)| K #GT# 1:
" H$ {, W7 G9 ^* q3 C3 c
0 m' V; ?2 Q3 V9 i. D  ! a vehicle does not travel inside itself,...;
# d5 q3 z: s! J0 p, r     X( K, K) = 0;

0 Y2 P4 b2 e6 h( A  ! a vehicle must enter it,... ;
. k$ x$ e7 l8 ?     @SUM( CITY( I)| I #NE# K #AND# ( I #EQ# 1 #OR#
' _( \5 D% O9 N# E) h5 N      Q( I) + Q( K) #LE# VCAP): X( I, K)) = 1;
7 r8 m# e! J) K' u0 f' p
  ! a vehicle must leave it after service ;
3 K1 N  O* R) Q" f     @SUM( CITY( J)| J #NE# K #AND# ( J #EQ# 1 #OR#
$ A! G3 ]# i4 W; M' f* m% P1 h      Q( J) + Q( K) #LE# VCAP): X( K, J)) = 1;

  ! U( K) is at least amount needed at K but can't
" u' z, ?* T% A) E    exceed capacity;
) L. [, [( m) z9 s$ e8 J     @BND( Q( K), U( K), VCAP);
# h* R7 }* d! c* p3 l. H$ {1 N
) j& H  t' X5 u  a  ! If K follows I, then can bound U( K) - U( I);
     @FOR( CITY( I)| I #NE# K #AND# I #NE# 1:
7 j$ w* e8 h0 ^% v/ X1 m. b      U( K) >= U( I) + Q( K) - VCAP + VCAP *
       ( X( K, I) + X( I, K)) - ( Q( K) + Q( I))
        * X( K, I);
9 _9 m' ?8 \1 _     );
* \8 F$ W5 d- U: U
  ! If K is 1st stop, then U( K) = Q( K);
     U( K) <= VCAP - ( VCAP - Q( K)) * X( 1, K);
' Z) K: {3 r6 {, ]
  ! If K is not 1st stop...;
     U( K)>= Q( K)+ @SUM( CITY( I)|
% c5 g2 F% K3 k, |# F( Y      I #GT# 1: Q( I) * X( I, K));
. V4 @0 o' ^& N1 ~; [% y0 n; m, d   );
+ I2 H6 l* Z- n$ d5 D( v
5 P+ Z8 Z( b; f5 _  ! Make the X's binary;
8 Q! y5 r# T- h5 o+ t0 q/ {. Q   @FOR( CXC: @BIN( X));
& W* N8 {; c& P0 `8 ]& I( r
  ! Minimum no. vehicles required, fractional
    and rounded;
0 ]0 E2 r5 \$ P3 \   VEHCLF = @SUM( CITY( I)| I #GT# 1: Q( I))/ VCAP;
   VEHCLR = VEHCLF + 1.999 -
    @WRAP( VEHCLF - .001, 1);
% b3 _" w$ e0 e9 _
$ C% u; ~. x1 N- G, {3 z& D  ! Must send enough vehicles out of depot;
; r, s) F; T: {8 G7 i! h* O   @SUM( CITY( J)| J #GT# 1: X( 1, J)) >= VEHCLR;
END
请问大家里面U(I)的公式如何理解啊 U(I)是城市I 的累积交付量么？谢谢