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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。
4 d' X( |. w2 c: I( |' Y; }netlogo自带的social science--traffic grid这一例子当中,
5 E1 }+ d% ?( f( ~globals
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2 [9 _4 M( x" @4 Z2 ^ grid-x-inc ;; the amount of patches in between two roads in the x direction
2 Q% b- k* Z/ i grid-y-inc ;; the amount of patches in between two roads in the y direction
9 G/ M. Z6 ~3 _1 B3 d1 c acceleration ;; the constant that controls how much a car speeds up or slows down by if- _. D, s6 c: P
;; it is to accelerate or decelerate/ O/ P9 k; i: I- F' C' x/ [2 \8 i
phase ;; keeps track of the phase6 R2 e, w! @8 o" T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, u4 [* t7 X+ I
current-light ;; the currently selected light
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8 r" c m! h1 d/ V) R7 B ;; patch agentsets
* E5 z9 \4 |& X8 W intersections ;; agentset containing the patches that are intersections: [7 K3 ^0 k9 ~6 _/ }+ v- @
roads ;; agentset containing the patches that are roads3 K# X6 \. z, V4 s* W! f' ^ U
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, ~; H" _6 y$ b p! Bturtles-own
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speed ;; the speed of the turtle
2 ?. J2 Q. }1 j. m up-car? ;; true if the turtle moves downwards and false if it moves to the right) O; C" t8 b( r: d/ }! w6 d& |" H' }
wait-time ;; the amount of time since the last time a turtle has moved! u( q1 O$ }6 `/ f% ]
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads. G9 X, x( A% w; V
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% z: `8 G4 {# j9 u ;; false for a non-intersection patches.6 N4 E2 L% D! @+ ]
my-row ;; the row of the intersection counting from the upper left corner of the0 T; q" @) N! s7 G5 z5 R
;; world. -1 for non-intersection patches.7 G* w* c5 `% I5 l! f4 c
my-column ;; the column of the intersection counting from the upper left corner of the j9 h- B2 S4 }1 a/ I8 G4 u
;; world. -1 for non-intersection patches.
2 p3 `- l0 }9 V9 p& |0 j my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 \2 g" N- g7 {& q, q. }& Y
auto? ;; whether or not this intersection will switch automatically.
& `, u2 ?0 n% G/ J! ~1 H# w% I ;; false for non-intersection patches., O# l3 |( Q! N9 q- G
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5 |( o9 \, f! q" G6 i;;;;;;;;;;;;;;;;;;;;;;
! z7 o, R, `2 N2 w4 b- w% ^;; Setup Procedures ;;
; K1 D: |* M& ~& ?2 I# h! l/ `2 O# f6 d;;;;;;;;;;;;;;;;;;;;;;) H- G# _# z6 O& l/ i% N( o
6 J8 i' Q% x$ c2 L3 v% g0 b) ^;; Initialize the display by giving the global and patch variables initial values.
; m$ }) _& G# v;; Create num-cars of turtles if there are enough road patches for one turtle to
; h9 ^3 p1 |! [. H) e;; be created per road patch. Set up the plots.
$ k% d G7 j2 V3 _4 e9 Y6 X9 fto setup
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2 M! r& q& H2 L setup-globals8 y0 `1 F. @* U" M0 M
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;; First we ask the patches to draw themselves and set up a few variables
, }" p0 Q* m& P6 }( r( A setup-patches
* S2 |7 g! I2 X& b' G8 h+ T [ make-current one-of intersections( p% o5 g. }! ?' ?
label-current' O0 y- c1 h4 k }
* i( L* G8 n5 e set-default-shape turtles "car"
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if (num-cars > count roads)' h8 h G3 T" e$ v q- q
[
. p) U/ b L/ K" ^ user-message (word "There are too many cars for the amount of "3 t6 d+ H4 @5 |) O! A V! I
"road. Either increase the amount of roads ") M/ x g0 r# ]' V5 U# f- X
"by increasing the GRID-SIZE-X or "5 J7 B) E/ r% V# ~. _
"GRID-SIZE-Y sliders, or decrease the "
4 `) l& T' ?! ~# m! I; Z- b- ~ "number of cars by lowering the NUMBER slider.\n"- q2 {0 A$ W; ^9 f# G/ D+ H! @
"The setup has stopped.")0 N; c9 n% l# n) ]
stop
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/ y" v, @: a, c) \- P( k ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 ]3 H# w5 l) d- q: ^7 x. A crt num-cars
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setup-cars
1 `% @- |. H) W set-car-color
) E: L: `* a5 P/ J8 n record-data+ g" z3 x0 r( h% z9 W5 @
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& K: |6 H$ w: f3 Y5 j ;; give the turtles an initial speed
1 r# H& P0 q. N4 M ask turtles [ set-car-speed ], T) R& R' ?$ m
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reset-ticks
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4 t0 w/ ?) N5 `3 [( n;; Initialize the global variables to appropriate values5 j B3 H, }$ b, k7 T1 ^
to setup-globals
. T$ ` |0 A9 H5 z7 }* O5 r set current-light nobody ;; just for now, since there are no lights yet
; T D- Q( @5 d/ p; H set phase 0
h9 X: w5 c, W* S9 ] set num-cars-stopped 05 `) X/ f- {; m. W7 [$ P& H/ g5 V
set grid-x-inc world-width / grid-size-x) H5 s9 q2 }2 N9 h" _
set grid-y-inc world-height / grid-size-y) K' H# r/ m( j% Z, n5 e, Y8 X
% x" d1 R$ {& m; L ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& ?" Q2 `- B, n set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 R7 @7 t! g$ ^9 t' J;; and initialize the traffic lights to one setting
( g, ?6 m( r, Q9 Uto setup-patches
9 ]4 a6 v1 i+ d ;; initialize the patch-owned variables and color the patches to a base-color
2 G+ C7 k2 b( c ask patches8 X! e: R* F6 n9 z C$ ?7 j1 O
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* [4 n* |5 A2 f/ r. n" L. {1 U1 R& g set intersection? false7 l: j) c1 L& |
set auto? false5 r: |/ ^/ @7 _
set green-light-up? true
9 d1 g$ T# m/ b2 x' i set my-row -1: l0 t& @* u; E6 `6 ^
set my-column -1, S7 i2 u0 L) D9 p! w& q0 l; d' u* C
set my-phase -1
0 ?; m9 c, v% y3 v" S+ q4 d set pcolor brown + 3& T( @( Q! p! L' ?- Y( ]' O
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% J$ c( i) {* G, g- [1 H ;; initialize the global variables that hold patch agentsets
' H+ l) r+ A8 i" E; ? G- h. A set roads patches with
: m8 Z2 I" T9 }9 N J1 U. l% ]. F) y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 f5 \9 q) M& T# b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( u4 w8 o2 q& G& B$ K- M! j3 b
set intersections roads with. F6 W7 B6 ^& G2 H$ _) ~: Y! X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 I4 f' O% C/ O3 T* t0 p, L" Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 h5 q0 O( X, i5 H' N. q- F
+ h& v3 }2 b1 T ask roads [ set pcolor white ]
Y* j/ `- W1 {& i: @+ `4 `8 I: V2 S setup-intersections4 q* G2 p% J0 V! Y4 F, @! K3 ?+ i
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其中定义道路的句子,如下所示,是什么意思啊?
& R2 H+ v9 k# X! ^8 f0 ? set roads patches with
6 ^% _4 P& ~4 t- K4 i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 _" W$ q" a3 I5 X1 x/ u [4 K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" _/ c# X) n/ q+ H' J. Z
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? |
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