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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 {( s4 P4 |0 ?/ t+ ?, f3 u/ Snetlogo自带的social science--traffic grid这一例子当中,( M1 A; z* L# T' G4 u3 ]
globals$ ?) s5 w# t; w& s6 o E7 l
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grid-x-inc ;; the amount of patches in between two roads in the x direction
8 ~) A$ A- ^. C3 Q! W! G+ I) L grid-y-inc ;; the amount of patches in between two roads in the y direction
1 |6 Q, D* U0 D" v acceleration ;; the constant that controls how much a car speeds up or slows down by if* N# w, Z t8 {! V$ {
;; it is to accelerate or decelerate
5 ? D' y7 V9 F. v) R( a phase ;; keeps track of the phase9 ? H- f, P H
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ p8 D5 t5 V& R7 `9 Y current-light ;; the currently selected light2 T9 V' { x4 Y: e/ ]% u% O
. I' ?+ A) w' L' s5 ^, y; T ;; patch agentsets
- f% y: P" ?; U intersections ;; agentset containing the patches that are intersections2 b, }/ P/ T- ]4 |# u" P
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
" m7 ~# u. s( H# p; q3 x up-car? ;; true if the turtle moves downwards and false if it moves to the right. B! Z g, F+ V7 J8 }- n$ b
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own7 Z9 \1 g! }- J' `
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intersection? ;; true if the patch is at the intersection of two roads
- ]) C- U, l8 i green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 f, `! U V" g2 a. K
;; false for a non-intersection patches.
) w* B0 x$ y$ T' z Q8 F my-row ;; the row of the intersection counting from the upper left corner of the
( A2 X$ y, ~3 O% e% u ;; world. -1 for non-intersection patches." ?6 s4 z8 f J- R5 M
my-column ;; the column of the intersection counting from the upper left corner of the& w* ]6 O' l9 ^9 ?0 [
;; world. -1 for non-intersection patches.! D0 Z- n g5 y1 I) Q$ K$ m) j; }% Z) g
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; U& O( H* n8 j7 g" @: ~' B auto? ;; whether or not this intersection will switch automatically.; K" ^0 M: ]1 }( h5 j& Y" z
;; false for non-intersection patches.
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+ y7 k: Q) {+ D& A& q$ L;;;;;;;;;;;;;;;;;;;;;;6 G' X. i/ Q0 l0 U9 n
;; Setup Procedures ;;
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. w; {6 H5 V1 Z7 s, `;; Initialize the display by giving the global and patch variables initial values.* H f7 } R: z; L
;; Create num-cars of turtles if there are enough road patches for one turtle to4 i. f+ ^6 v# R2 j- C
;; be created per road patch. Set up the plots.) d2 I1 V: V, X; }" V, V, Y ~8 C
to setup
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setup-globals
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$ I! H0 ^ R7 c7 c, D$ s ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
^7 V3 T1 O2 f9 e, d8 c/ Q label-current
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7 u; R& t5 J8 e/ H9 K; t set-default-shape turtles "car"
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if (num-cars > count roads)3 G: Z( t# k: [6 e! L
[
" y6 j/ w8 C* G2 g& Y/ c" @6 [. u user-message (word "There are too many cars for the amount of "
( S7 f2 `! t& H \ "road. Either increase the amount of roads "- G- l! s% C% Y! H0 [) h, [7 T
"by increasing the GRID-SIZE-X or "
/ \; I+ Z: i D+ v) {4 J0 n2 S0 X "GRID-SIZE-Y sliders, or decrease the "( ]7 v" b" `- ^" y7 {4 ?( H
"number of cars by lowering the NUMBER slider.\n"
|5 u0 S2 F: D. m" Q; U2 q7 R1 _ "The setup has stopped.")- J( a0 o9 ~1 a, L) `6 ~1 j
stop. L) y2 B2 I6 ?% d9 S- \
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 z' q( x! c! Z7 A5 I
crt num-cars( R0 f+ r) ?: @+ H% {5 c
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setup-cars7 _; b. |3 g6 u. [: S ?; r' j) x& o
set-car-color& b* B0 o# r' o+ a8 O2 A9 g; n3 A8 C
record-data$ V$ f- C1 ~2 p% r4 S1 P' Z
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;; give the turtles an initial speed
. r7 B* H+ A; F* \& a3 J ask turtles [ set-car-speed ]: j4 C7 d; B* O! B' J
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reset-ticks
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+ l4 u1 X7 H# l/ X$ |6 o% t;; Initialize the global variables to appropriate values
& a7 a3 _. C( |$ W2 O$ Ito setup-globals
; N; O1 Q4 B5 e* N6 L% f' o. q$ s, k set current-light nobody ;; just for now, since there are no lights yet4 l5 A) X2 k) T4 _8 E
set phase 0) N( V- x& R5 B; J) r. `; z
set num-cars-stopped 0
0 W9 E) N& v# O set grid-x-inc world-width / grid-size-x( }; Q W) R5 `9 L( H. H: {$ y
set grid-y-inc world-height / grid-size-y
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! V+ ]" v: ~# @9 ]% |, }6 b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 I, r8 t1 e7 a8 s8 E# @/ C
set acceleration 0.0995 l% |! T$ L* [. ]. e- ~
end9 B* h- I8 q# s% P
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets," Y2 P7 z: q% d+ F
;; and initialize the traffic lights to one setting
# v6 D, @4 {% W8 B3 L& Oto setup-patches7 t& C7 R! ^* a( ^
;; initialize the patch-owned variables and color the patches to a base-color& X4 x b& ?' Y/ g, O' Q- b
ask patches
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set intersection? false7 K$ T& n# z/ q7 L$ X) d& @
set auto? false' C8 I h& e) C2 k
set green-light-up? true4 L% e/ }9 j- E+ i: O
set my-row -1- s: B8 p9 Y& b4 W/ O# S
set my-column -1
. `7 _) B* |& G/ f7 l) b set my-phase -1
% H' X0 r9 S& X; Y" g6 Z2 H set pcolor brown + 3# v4 D# c' f$ p4 g
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. e' A2 V f8 f$ b ;; initialize the global variables that hold patch agentsets3 q, T6 h/ j( T4 B9 J) |
set roads patches with
+ v: Z/ P9 y$ w6 e, x) |0 } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) b- e; R, u3 l: }5 d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. H3 {5 @! R* I8 S7 A4 _5 M" ]5 t set intersections roads with! k) k3 ]+ |% L) [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' e7 E8 E' A/ t' `4 i" w$ d4 G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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* k8 `" Z3 V1 B9 m* W5 \- q ask roads [ set pcolor white ]
2 p5 O+ g2 D) l) f setup-intersections* e3 U# m- A9 c' S# K
end' `# X7 r+ C, Z, ^1 W+ I
其中定义道路的句子,如下所示,是什么意思啊?+ O3 C0 }: _7 N
set roads patches with+ b% T+ m$ Y0 S" f/ \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 C8 U2 L3 U6 A! i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 S$ `, O/ z$ S. `6 V2 U0 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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