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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 a2 s+ f! m2 _/ b0 b# F% ?' j
netlogo自带的social science--traffic grid这一例子当中,
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1 }2 m4 `9 w# Q. S grid-x-inc ;; the amount of patches in between two roads in the x direction5 d6 w; X0 [0 s m d t
grid-y-inc ;; the amount of patches in between two roads in the y direction
% O2 i/ ?# l4 T3 p R acceleration ;; the constant that controls how much a car speeds up or slows down by if
- m9 h2 o' R$ J3 y ;; it is to accelerate or decelerate
8 N4 U# n' M9 J; R/ p phase ;; keeps track of the phase
9 ]. ^- I0 V& s0 |& l num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' \1 L m7 C" N- ?
current-light ;; the currently selected light
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;; patch agentsets2 V, Z2 Z! }$ v- W& |8 y1 W
intersections ;; agentset containing the patches that are intersections
/ j) R9 M3 e# v0 {# J9 u5 |. y roads ;; agentset containing the patches that are roads) L$ t+ z" C1 K( w- y
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turtles-own
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speed ;; the speed of the turtle0 a# g5 l' X! X2 y/ R/ s, A7 H! ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right: c/ {- ~$ S/ c* E& V0 p) Z
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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+ k( O8 K: ?+ M6 G, u1 Y intersection? ;; true if the patch is at the intersection of two roads
1 I% B7 ]) c; A: f) j" a. H7 ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 W# \* n3 U! q4 N6 \' F ;; false for a non-intersection patches.. h/ h! q: b* _0 r" V
my-row ;; the row of the intersection counting from the upper left corner of the
3 O% X+ y8 A: D2 V ;; world. -1 for non-intersection patches.& Q, X2 y2 [1 s
my-column ;; the column of the intersection counting from the upper left corner of the
5 f7 D( E/ s8 c7 D* o7 ^0 W6 Y$ d ;; world. -1 for non-intersection patches.& H2 Z' D; W/ g2 d
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 _% {$ j3 @, ~5 S$ P* e3 | auto? ;; whether or not this intersection will switch automatically.( v# ^& h. o a1 t
;; false for non-intersection patches.9 d* j# Q" D% n( f
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! f( a6 s( x1 H;;;;;;;;;;;;;;;;;;;;;;: U: B7 Y1 e7 S* U h' s- E
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.4 F! @% c7 p: A, ^
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 X) n5 j9 E! v9 x2 L) Z2 m; y;; be created per road patch. Set up the plots.
% K8 y) Y$ z5 f, Mto setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
+ f9 b$ I% R7 s* T5 Z5 ` setup-patches
1 B e7 A! O3 M4 \2 @ make-current one-of intersections$ }3 P8 i) H! Z: F, l7 C
label-current/ G. p" i7 F! }: a. c) N
4 G2 u8 Z" M) U/ v; X9 y set-default-shape turtles "car"2 L1 f; o' s: W- f& A: y1 q( p
4 P' Q. W3 k% _# v6 N9 O if (num-cars > count roads)" o! u. O: s* g3 G
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% _2 g# d- e/ r- }- }( s- }- a6 s user-message (word "There are too many cars for the amount of "$ C z5 J/ ~! \: O
"road. Either increase the amount of roads " W) B$ [' |+ s- F. H/ ?
"by increasing the GRID-SIZE-X or "8 M( h' i+ Q6 q z+ r$ t9 {
"GRID-SIZE-Y sliders, or decrease the "
4 p& b5 m1 {8 r# H) } "number of cars by lowering the NUMBER slider.\n"
4 X( M2 z/ N4 e" G "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- C: k$ `% F+ |4 l crt num-cars4 `; P4 Q. |6 E N: v, j
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setup-cars2 n/ E; X* z; }! S* D) v
set-car-color1 r& x% A/ b. R, _. ]; m
record-data! ]: r8 C; M+ Z' {! X1 z/ k! u
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/ \) O* p0 z$ T# C% M* T; ~ ;; give the turtles an initial speed
/ q1 D" K0 U0 q8 n j! \ ask turtles [ set-car-speed ]6 M& T; A X8 ~( g; [. g( \9 ^& @
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reset-ticks! r( q. E' l# K) d Z9 ]
end* W% O4 {7 {' R( J$ V6 p0 m
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;; Initialize the global variables to appropriate values1 A1 g* W- T% H& {$ }
to setup-globals
V: y- c+ `' S) \( l% o set current-light nobody ;; just for now, since there are no lights yet! d) U4 k3 R$ c) X
set phase 0
. |& t- ~( z) S2 e" z) G5 z/ X set num-cars-stopped 0. r/ G& G3 w, b' v# f# `: L2 ^2 z; b
set grid-x-inc world-width / grid-size-x h( \" e' {* f* b( f' a) T5 g4 i' ?
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 ~/ M8 G6 E2 O8 W5 Y) X2 N+ G set acceleration 0.099! {, J4 q& j: D! A! M% a
end
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6 s1 X/ T8 ?; C' A$ g! ];; Make the patches have appropriate colors, set up the roads and intersections agentsets,* n4 p4 `, p6 M4 I- @, m6 e( G
;; and initialize the traffic lights to one setting
" X# T/ l! F' C0 e. @to setup-patches
/ h3 u Y! f+ |2 |$ R( U7 T ;; initialize the patch-owned variables and color the patches to a base-color
7 C4 K* l' o, V9 p/ b3 e" O ask patches
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set intersection? false
I I) l9 {5 P# N set auto? false# i' _/ h0 F% V# }) ]. b0 ^
set green-light-up? true- {0 w% B& H# i X6 k. Q8 W- W
set my-row -11 x/ T4 F* [ @8 A# l$ R
set my-column -16 K; w9 b! I' w" _: |& D3 u
set my-phase -1: D: v% M$ d$ f- [# ^
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets; g- V- D8 W% ~& e
set roads patches with
4 k% c9 O( B+ B) O0 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 z2 k$ h- O9 c7 f, I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, s, f0 R% D2 {0 k5 p; e set intersections roads with; }# A. D. P. U' u" \9 Z/ N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and" `6 d# {- r7 {6 m C
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; |# }: G9 c3 o& C" F" V# j
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?5 Z' a* C/ Z; w$ r b* K
set roads patches with: {! ]5 t1 t7 Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' I% ]2 B$ h$ O2 f1 { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* y" \. n0 S- [9 \4 m; L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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