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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。1 Q2 c! W# h% v; E! @7 s% w
netlogo自带的social science--traffic grid这一例子当中,& r+ F0 W. ^* Q6 r; T Q
globals4 W- d& i6 {3 ]& F4 |, r
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grid-x-inc ;; the amount of patches in between two roads in the x direction
- g( D/ c6 ^+ m( B' a' M( l; T grid-y-inc ;; the amount of patches in between two roads in the y direction
" Z& _5 B; r. y/ E acceleration ;; the constant that controls how much a car speeds up or slows down by if1 G. E7 ?( `7 z4 N0 |
;; it is to accelerate or decelerate
! {* T/ ~3 ?# I' x ] phase ;; keeps track of the phase
- o8 m7 }: @+ ]5 x1 \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! `9 v8 J8 R8 Q8 b
current-light ;; the currently selected light7 @, `9 G6 g5 [, K8 ^ ^
; _% {; {1 N- Z+ o4 x; I ;; patch agentsets
, v+ ~8 b( _, R# M- }1 j& O intersections ;; agentset containing the patches that are intersections
% g, W! i0 I$ `* Z6 K roads ;; agentset containing the patches that are roads# i4 y: L4 x' R- P( W
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turtles-own! u3 D( L0 b9 N5 A' U
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speed ;; the speed of the turtle* q+ u$ Y ^$ u p/ m
up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 a6 s* M% C: U; u wait-time ;; the amount of time since the last time a turtle has moved
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. W+ w6 N2 h' |9 Mpatches-own
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* A% i& P: P2 }, _3 E intersection? ;; true if the patch is at the intersection of two roads
/ r8 z* v5 A) m d green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. Q1 v' z+ m# l$ S5 Q) K- b' V: ? ;; false for a non-intersection patches.: \: g8 N/ n( k; p9 H2 f( ^+ b
my-row ;; the row of the intersection counting from the upper left corner of the( p! m1 U4 }9 N) C* d0 r
;; world. -1 for non-intersection patches.! D+ @6 L- L* z% W9 n/ s }
my-column ;; the column of the intersection counting from the upper left corner of the; O1 y2 z; E7 V# ?
;; world. -1 for non-intersection patches.
* r2 Z t/ e4 f my-phase ;; the phase for the intersection. -1 for non-intersection patches.! v# E8 |% c* @4 E5 a" A0 F
auto? ;; whether or not this intersection will switch automatically., U6 C/ {2 V8 q3 v# S0 S
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;6 {$ k' @: ~8 e; t8 m9 q) |. x
;; Setup Procedures ;;
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) f0 k" G2 I' P9 j; [8 P* @ ~;; Initialize the display by giving the global and patch variables initial values.. I9 d' W# Y; o' c
;; Create num-cars of turtles if there are enough road patches for one turtle to2 O2 c: d, Z Z' P M. Q
;; be created per road patch. Set up the plots.
; q4 C4 Z0 Y. s, {4 b" Qto setup! I% T: C. R! I% g. U3 i; R
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setup-globals/ |) W7 P9 }$ N; z" L% [
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;; First we ask the patches to draw themselves and set up a few variables9 `' g4 ?8 _9 h
setup-patches Q5 N+ V$ O: m# q9 E8 R
make-current one-of intersections0 S2 {: N* G; q$ ~
label-current+ g/ ?1 n# h$ i$ S7 e/ K+ _
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set-default-shape turtles "car"
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2 l4 d+ q; L# [ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
: ^( A2 N% F; V& Q. a$ \+ w "road. Either increase the amount of roads "
# d' A; c$ o' F; u "by increasing the GRID-SIZE-X or "
: ~$ }3 H! f A- q5 n+ t "GRID-SIZE-Y sliders, or decrease the " y/ B8 n3 a6 R! G+ C
"number of cars by lowering the NUMBER slider.\n"
& y U' p% K; n; l' v0 ^ "The setup has stopped.")6 O* `/ B! g; j! H8 `" \
stop
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2 Q* h$ z8 Q4 ?' |4 l ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ E! F& S' J, L' q; p crt num-cars
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; F, i6 Q! v) T2 S; L7 O setup-cars- W& g: v b3 g- S: D
set-car-color8 {7 K* w8 s3 F( l7 v E: m
record-data4 h5 t; D. u) ~" U s
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6 Q- N Q& u+ A3 | ;; give the turtles an initial speed! Q4 `9 B+ Y) l# F: c, V: Z& t
ask turtles [ set-car-speed ]4 ]) J+ x) H, u, N
. u" r5 E& j# N reset-ticks
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0 i! n1 k; G: c \' i% n& p; t& G;; Initialize the global variables to appropriate values; L( c3 ^& ^/ q
to setup-globals1 U* A7 b6 Y7 j7 Y
set current-light nobody ;; just for now, since there are no lights yet8 N: l4 o) @! e. }; x& P
set phase 0
1 p& W3 B6 u9 }# K$ E* N D! E set num-cars-stopped 00 ?' G- f J( i' N6 M( U# w
set grid-x-inc world-width / grid-size-x
3 n9 w# ^1 U* D/ n3 B5 B set grid-y-inc world-height / grid-size-y. m' T) @2 j* i; _7 R* K. c" G5 t' j+ L
5 ^: h+ J( I8 U; T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 u& X" P6 S: o& O
set acceleration 0.099' t+ K+ D8 ^; }$ A4 \
end2 @# Z# a7 Q7 C% K/ X
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! J2 A: {1 P4 K8 `
;; and initialize the traffic lights to one setting7 y) X: i. n$ W* f5 T3 j; t4 b
to setup-patches
% x9 G) z; i9 }8 \- I0 k* j' ?/ R$ R ;; initialize the patch-owned variables and color the patches to a base-color. e$ o/ g' X5 I2 e0 S; ]) \
ask patches
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set intersection? false, C; o: Z0 } f) y( q% n( K5 q* D, \; L
set auto? false) O3 v' X' z: X3 f& p) O+ o9 f
set green-light-up? true
5 {# q$ A2 P# x4 w ?: ~6 B4 i set my-row -1% N: k2 V1 `. E5 c& R2 ]; m# n) O
set my-column -1% X T/ D6 [: {0 ~
set my-phase -1
7 \, G# \5 Z/ z& f- E set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets7 J) o4 r+ A7 C/ b
set roads patches with$ {$ c4 @ Y5 l- x3 z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 t7 m. u# ~$ z% `$ l( c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 I' d) q# L4 H set intersections roads with9 Z. g+ O$ r; A$ T* [" J# T. O6 \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 \8 Y, s1 r7 J B9 @+ c" L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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* N$ r! l' K' P+ |: ?* n7 h ask roads [ set pcolor white ]
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" U1 @0 _# A2 i9 ]$ ^其中定义道路的句子,如下所示,是什么意思啊?
% P. m/ m- i8 @( ]# { set roads patches with
% E/ Y2 j; e7 D3 J0 K8 c, _( f( i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 N% n4 n5 u2 t) S G; Y& w( \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' Y U' @2 Q8 o
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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