|
|
新手,在看netlogo自带的例子时,有几行程序看不懂,希望高手能够指点。1 h% a% J, O* a8 L# k/ R
netlogo自带的social science--traffic grid这一例子当中,% ^5 I8 Z' S" x2 [* o5 X+ y
globals6 S. s# k- P7 F. n/ n% G R
[
/ e' S& d. l1 w) f grid-x-inc ;; the amount of patches in between two roads in the x direction+ Z1 @( G7 N6 N
grid-y-inc ;; the amount of patches in between two roads in the y direction6 _% X2 h" i2 c* M2 b2 `% B9 V9 K
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ K, z! K0 I: d6 H6 F5 W ;; it is to accelerate or decelerate' K, R4 n) [# D4 n2 P% p+ e# b
phase ;; keeps track of the phase
. O7 {6 K' y) P! B2 g num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" F; @ B2 j" R6 c/ C current-light ;; the currently selected light
: q$ Z; K" |, i& h* ^" v6 @
h$ t- C) D0 E- h ;; patch agentsets
% f5 F& A' j/ N1 R intersections ;; agentset containing the patches that are intersections
9 u( I* P8 j/ |4 ~ b roads ;; agentset containing the patches that are roads
1 A' K" u: l0 t. i1 m2 t]$ c: Y9 C8 R! d$ [0 J
! a {( a8 v6 |8 z4 f# Vturtles-own2 F2 R# Q( S& n! I2 Z) C1 n6 d4 j
[
/ @: g7 S X" c( g1 Q speed ;; the speed of the turtle
X! ?3 u6 ^' ^1 v( ]0 t7 d up-car? ;; true if the turtle moves downwards and false if it moves to the right" l E+ y) L" o1 f/ R
wait-time ;; the amount of time since the last time a turtle has moved
) g6 G" \" d. m) j5 {. {$ V w7 o]
0 [' H" o) ?( I
- r7 P- L! T' U" K0 t- y' E% T* n) A2 tpatches-own
% ?; S, e4 H* f3 u. e3 D[( Y# I9 v! H6 f" b$ L$ V2 F
intersection? ;; true if the patch is at the intersection of two roads! L- n" C9 ^0 I
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' _" W: C* E% Z# _ ;; false for a non-intersection patches.) ]* S y& e8 w; G z7 s
my-row ;; the row of the intersection counting from the upper left corner of the
4 v0 u7 U- x/ }& W) \ ;; world. -1 for non-intersection patches., _! _, e/ l1 r% P) d
my-column ;; the column of the intersection counting from the upper left corner of the
. I+ ?( A3 }+ y4 \; k ;; world. -1 for non-intersection patches.
9 x$ t1 n1 ^( A& y) c$ g my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 ?* C' }* p3 I5 r auto? ;; whether or not this intersection will switch automatically.! o1 u, R4 ^; a4 b" A
;; false for non-intersection patches.% w! q* w) n8 ?8 J
]
2 h- H3 a% h6 m1 y/ `
4 s! j9 W. u0 L5 X- C+ ]& g
, N8 I& F) g4 ^% M& @; K;;;;;;;;;;;;;;;;;;;;;;
7 _5 M0 x7 c5 E; T# R;; Setup Procedures ;;
9 v) A) g0 c9 R' q4 l- c% |;;;;;;;;;;;;;;;;;;;;;;+ f& r, D. Q, ^) y
0 `0 ?" B' A, k, U! x
;; Initialize the display by giving the global and patch variables initial values.0 d/ I" ^: p: R+ f) x. q$ ], h
;; Create num-cars of turtles if there are enough road patches for one turtle to2 I6 F9 Z9 J6 I/ I* @
;; be created per road patch. Set up the plots.
5 [# U1 S7 d0 [to setup
* O( M3 w4 e7 Q2 n0 j6 |( W4 T ca
" p% U: y ]& d: {- c setup-globals( v% B$ u1 i- ~" O
0 ~9 J# r" ?, ?- w9 l ;; First we ask the patches to draw themselves and set up a few variables+ O6 t; |* B" D: C
setup-patches
, I1 Q2 z H( Q" X3 H+ D! R make-current one-of intersections
3 x9 \8 t4 f$ \2 R3 S/ M' R label-current1 N) ?# G* D' x$ i) D' f3 r% g) g) B
4 p) r/ ]. {. j' ^9 V set-default-shape turtles "car"
a/ a; j: n3 @
8 r: Y: Z8 Z$ c$ H! v if (num-cars > count roads)2 m2 w7 U9 l+ ^% h; m& M
[
. ]; ~" ^; B8 `1 z user-message (word "There are too many cars for the amount of "$ L) {* O# @* J g- n/ m0 Z
"road. Either increase the amount of roads "* P. [2 s( Z+ a7 f$ l
"by increasing the GRID-SIZE-X or "2 _3 ?, b8 o2 D
"GRID-SIZE-Y sliders, or decrease the "
/ ~. R& V4 \0 j "number of cars by lowering the NUMBER slider.\n"* d! K+ c* r- P& M5 y @( [# d
"The setup has stopped.")
+ N' \+ j5 A) @3 S! @ stop
( U5 [& e: B5 F+ v) g$ L, g ]
( Z# S( ^$ b3 N P% n2 B6 C& D: K1 r9 q1 C
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 O0 c2 s( X& v: P1 y8 v
crt num-cars' D: A7 T3 i, |" o, o/ Q. z
[) m/ x8 J9 f) U$ s' R; W3 ?
setup-cars* `2 m) W( E" L) p
set-car-color
5 l. d" o. ?! Y: ]" M1 T record-data( `1 f3 D$ w: T, p; f
]
/ `) M5 O- d$ y- _3 F7 C: t# B* a& X
;; give the turtles an initial speed% V# C+ J9 y) _" k1 F g I
ask turtles [ set-car-speed ]. D M$ g3 V+ }
0 w- ]) G/ b- F: |4 ` reset-ticks
5 H C9 l, P. \+ Dend
6 F% R' b' ~, I9 x4 q* h+ Y9 ]. | J6 {* p
;; Initialize the global variables to appropriate values, M. I& d) x5 f% q0 O1 u& A4 \2 k
to setup-globals
" }0 t( L5 x! p7 ^/ { set current-light nobody ;; just for now, since there are no lights yet
" @' l3 N, E% T. I% r; i set phase 0
2 Q- ^4 }3 U& f0 k set num-cars-stopped 0; A5 O. |( U, {( w" l! u
set grid-x-inc world-width / grid-size-x5 o# p8 Q$ S% k; l/ J3 E
set grid-y-inc world-height / grid-size-y
3 g4 N/ i' u& Z; R' F6 Q/ \! U9 o5 r# q _, ^6 o
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( `* o: l: G2 q/ i# l! v set acceleration 0.099
r: D, ~0 {: s1 v! Dend! b# G P- g1 S& r; N( M! j
$ { V* e( m* h6 f. S
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 M* A5 m+ b" Y;; and initialize the traffic lights to one setting% v4 Y% O" b3 R) N6 v
to setup-patches
3 e4 O( f$ E7 G% E) J% P6 S) [0 l/ P ;; initialize the patch-owned variables and color the patches to a base-color
- {! P6 A# W9 I' H$ E( g ask patches
7 P# A! d/ H; @0 [' O) d4 F [3 b# k$ Y/ Y* A( K P9 P" H
set intersection? false4 L$ ~( j1 R! U# _ e
set auto? false6 k9 h& S5 i: D! {
set green-light-up? true5 m& y# K' I3 M! p* @( I/ p& K
set my-row -15 x! W( k2 c1 U% U' Q @
set my-column -1
2 w! ^1 {0 f$ v5 ` set my-phase -1
$ K$ h8 n7 w5 V- e1 s set pcolor brown + 3( B6 | G/ C4 V" j/ R& D$ X
]
' J5 C3 a/ |! U' n0 h: A9 t0 w l% I. v J8 ^. i
;; initialize the global variables that hold patch agentsets
) Q- {/ {9 r! k' z set roads patches with
, j1 y$ r, w. C$ X, n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 [$ f3 a+ A @7 n$ X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' X) ]5 I; g* J3 d2 d set intersections roads with( @! W/ ?5 t6 b5 A3 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 U3 t2 w3 x3 w8 u$ j8 {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* x7 G% A B" g7 C
" J u2 ~4 A+ Y ask roads [ set pcolor white ]
9 H6 v5 M, |/ o+ R9 n0 W setup-intersections; S& s% |4 n2 S$ S9 V6 M8 h" g
end9 ^. T% R$ E1 O c% l$ V, m6 Q
其中定义道路的句子,如下所示,是什么意思啊?
) B) Y( ]- {4 r3 F set roads patches with
8 b0 a- v& `4 {- H+ [, i6 V3 f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 J0 { @: Z2 z4 W1 d1 B* E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 p; ]' S: Z- u/ U谁能帮我解释一下[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0)是什么意思吗? |
|