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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。
; n* q* Y3 s% P/ p: X A$ P' g7 Enetlogo自带的social science--traffic grid这一例子当中,$ m# U( p; g- w- L( N
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( S' F1 R# f7 X" g1 ]+ j1 P, x grid-y-inc ;; the amount of patches in between two roads in the y direction+ V$ J v+ t! Q, u$ U
acceleration ;; the constant that controls how much a car speeds up or slows down by if0 t+ Z" x8 ?$ f( q$ V G- m: h
;; it is to accelerate or decelerate
* S( }9 |7 ?$ W8 O: Q: m phase ;; keeps track of the phase
- W$ G1 a8 v1 u3 p% v num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' G- {: I' c8 s4 u2 S; e8 \ current-light ;; the currently selected light
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8 y' T5 y" \5 @6 h/ V ;; patch agentsets8 @# F+ b6 W Z' U" d" ^# G
intersections ;; agentset containing the patches that are intersections7 S- x: A# F6 k7 `
roads ;; agentset containing the patches that are roads
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turtles-own
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' T; ^2 ?4 A$ f2 |3 ^. A- i, \ speed ;; the speed of the turtle" g% |4 v; g; v+ w
up-car? ;; true if the turtle moves downwards and false if it moves to the right
, Y, Z; @! c, E/ L6 q wait-time ;; the amount of time since the last time a turtle has moved
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5 z/ ~. t* x/ W. j |0 Jpatches-own' m5 K" ]6 u1 p* Q
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intersection? ;; true if the patch is at the intersection of two roads
1 I4 o1 P! A5 d% q/ z green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 a$ _% `5 R9 d
;; false for a non-intersection patches.4 v1 k! V# x; G, h, `
my-row ;; the row of the intersection counting from the upper left corner of the
* M% z5 O6 j$ N# K; ^1 x5 f/ \1 W ;; world. -1 for non-intersection patches.
. a( x d" I" |: N- H" W" T0 `" ? my-column ;; the column of the intersection counting from the upper left corner of the- h! D) [3 o# c4 q
;; world. -1 for non-intersection patches.
; n! M C/ N8 B1 @ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& D, g7 t: \3 r, V auto? ;; whether or not this intersection will switch automatically.
+ g4 |$ [ c0 n8 [/ N$ `' ^9 }, Q; _ ;; false for non-intersection patches.
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3 a2 U& J! h) E0 p% h2 C( D;;;;;;;;;;;;;;;;;;;;;;% a, z6 i. g1 K& {. [4 y
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values." o, \# Q4 x* F" [/ }8 `1 g
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 j' n4 Q' W% D# C' g+ v;; be created per road patch. Set up the plots.
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ca
# F) b% s1 K. `- \* ^ setup-globals) n. ]/ Z7 S, {; t9 }3 ^ |8 Q
- w$ `5 ^3 m0 |4 O) x; p ;; First we ask the patches to draw themselves and set up a few variables
" K* C5 s9 P \, t0 c P! i setup-patches
9 b5 A2 u1 |( D# u0 |1 i4 e2 d make-current one-of intersections
& k% H# B! h# j* ?0 l$ _ label-current$ N# D! Z6 O9 g- {8 D& K' b
/ V5 F# M: ^- D5 T3 e* |" i set-default-shape turtles "car"# v8 z( m1 ~3 ~* M% k. V1 j
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if (num-cars > count roads)
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7 A$ {. t- A. b4 `9 P user-message (word "There are too many cars for the amount of "
- X0 f: F2 [+ ] "road. Either increase the amount of roads "
6 D( N* c8 [) h" s "by increasing the GRID-SIZE-X or " W K1 B( q+ ?0 X. Y; k9 o2 X, e
"GRID-SIZE-Y sliders, or decrease the "
# w6 C8 l4 Q1 g" G( N' Z "number of cars by lowering the NUMBER slider.\n"
/ }4 {0 o9 r$ U% i& m6 i "The setup has stopped.")
q3 v3 J, O3 `3 e# E% G2 X stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ X# f- t' _: c5 ^" O1 p
crt num-cars
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: v4 n+ l' L: m" U setup-cars
m% n- |5 A- A8 Q1 h, B4 r set-car-color
& B$ ?) G1 {3 c5 ^ record-data" q3 W& q0 } g' w7 O! a8 T" |
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;; give the turtles an initial speed
' K! O' k5 j9 w2 s& a ask turtles [ set-car-speed ]1 Z5 }, K3 \; o& T% b
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reset-ticks" V+ F/ l( A) W% _+ r8 C
end9 c9 F" V+ _% p
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;; Initialize the global variables to appropriate values# ?( U: k9 v, C
to setup-globals
) k7 b+ P+ a, i: l8 d( b/ |2 q4 ~ set current-light nobody ;; just for now, since there are no lights yet
$ O- X. @2 N# r set phase 06 Q! w% N! ]! ]7 Y( V. b
set num-cars-stopped 0+ K. g* M. @ |& B9 ?, t! a
set grid-x-inc world-width / grid-size-x/ u& d1 j Y- @! t. O/ S
set grid-y-inc world-height / grid-size-y v! m% Y: }6 I" ~7 Y) F
! L2 U5 V8 S- x4 D+ Z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 ~+ b4 b1 \' I M) W# @ set acceleration 0.099
3 Q4 c7 e0 r+ ?& g$ k6 Lend
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7 Z9 ^1 {! ]; _5 W6 [5 B% E/ ?* D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 w& d8 I2 ^- r0 D;; and initialize the traffic lights to one setting) Q/ p; \+ L* p
to setup-patches% b# g. n8 p8 l& z* G$ {2 x J
;; initialize the patch-owned variables and color the patches to a base-color+ X2 y- [' Y6 u6 {
ask patches
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9 a; A% s; ^& r( V# x set intersection? false
9 ?5 \2 H5 X% y( \ set auto? false
# \" [$ Z" ^! J. l set green-light-up? true
c2 G" F) h! g& C* F6 } set my-row -1
- d1 m- h- z; J, C* U set my-column -1
& i( k3 ]3 s2 i set my-phase -1
$ k: T0 s/ Y3 n set pcolor brown + 36 w" r+ x$ m1 B- i2 f
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' K q$ S( X6 c6 L* F3 _5 u: B ;; initialize the global variables that hold patch agentsets
* ]7 o% y* g X- U9 e set roads patches with
2 O; A( |2 K0 X9 v% d8 g: E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: G2 G( w; G( d( V* R3 V) g# {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 m/ J) V. d$ z/ H% i' u set intersections roads with, v$ w0 c- s/ S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, ^: y9 g% t6 | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( r+ c7 {9 d+ Z/ {+ L" x, t4 {% [; v
! c n& y' k' Y: { ask roads [ set pcolor white ]
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# N# y- a: p3 Q3 b C) c- p8 R其中定义道路的句子,如下所示,是什么意思啊?
: |. C* Z: I9 e) W$ ? J! [ set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ s. I! A5 O T) b) _" H
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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