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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。! W3 |0 b1 \! A- D, E6 S; I+ ]+ c; K
netlogo自带的social science--traffic grid这一例子当中,+ L- B; V. \6 @
globals
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2 ?* G) o: ^7 L, u% y grid-x-inc ;; the amount of patches in between two roads in the x direction
t4 y k: ?% i7 k- _ grid-y-inc ;; the amount of patches in between two roads in the y direction3 ]3 B2 k0 Q( {: _- m2 o
acceleration ;; the constant that controls how much a car speeds up or slows down by if7 x/ `4 T" K7 \3 s0 f
;; it is to accelerate or decelerate, d) c V, |) w! F6 z! G$ [6 l
phase ;; keeps track of the phase
' d+ X( @: M* I. [* v num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 {/ @6 p2 U' n2 j+ ^ X3 z6 f0 O current-light ;; the currently selected light p. v4 _4 m- v; p0 l% b0 q
; I: v1 Y. O; w9 w ;; patch agentsets" {: @* _" |3 S# Q ?3 q$ \" M2 e
intersections ;; agentset containing the patches that are intersections
: o! R: A8 J+ x3 v+ ?1 K% M roads ;; agentset containing the patches that are roads
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; _+ I6 g0 s: Z. C" y3 s( Nturtles-own2 i9 ~% z) l- r- y
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speed ;; the speed of the turtle
5 e2 R1 g! [8 a8 B2 ]2 a up-car? ;; true if the turtle moves downwards and false if it moves to the right
% b# h; X$ O& ~, [$ B wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
- t4 K; V; I9 ^! i green-light-up? ;; true if the green light is above the intersection. otherwise, false.! N% I6 c; O* o) M s7 _" m
;; false for a non-intersection patches.) s1 Q! i( U5 p9 ^& I( ^0 ~
my-row ;; the row of the intersection counting from the upper left corner of the/ S$ w7 S3 j2 d+ q
;; world. -1 for non-intersection patches.7 O# @( P: t T
my-column ;; the column of the intersection counting from the upper left corner of the. o" I, ~) f" R Z$ K3 \, ^; _
;; world. -1 for non-intersection patches.* d& m" n) {+ d$ u+ {
my-phase ;; the phase for the intersection. -1 for non-intersection patches.# r$ ~+ I4 @9 q$ K0 y) J6 [
auto? ;; whether or not this intersection will switch automatically.
( u) S( K8 X' B ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;' o) w5 t* u5 n4 U, G d* b/ L$ i, m
;; Setup Procedures ;;' g- ]$ K) p2 Y6 C; w! d
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;; Initialize the display by giving the global and patch variables initial values.% q- F! M+ L. g- B
;; Create num-cars of turtles if there are enough road patches for one turtle to* N n: l, U0 K5 p. k# z
;; be created per road patch. Set up the plots.
3 G) y: u) p4 c# T; K# |9 Qto setup
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setup-globals
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3 |: S9 x4 \2 x* v ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections' s% H# E6 S: ^1 Q) e1 a. g n
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)% i+ z8 Y1 M0 M& ~ A& A1 e
[
& m4 `; A7 k3 y' s# ^ user-message (word "There are too many cars for the amount of "
! @, n& O8 ~6 |2 ?! u "road. Either increase the amount of roads "
& H1 Z2 H$ F: Y1 q b "by increasing the GRID-SIZE-X or "
+ l+ D5 m& B# m' ~# R4 D9 n "GRID-SIZE-Y sliders, or decrease the "
N2 G3 Y4 }8 X "number of cars by lowering the NUMBER slider.\n"
( q9 _* e& P! P) o! T1 h/ Z "The setup has stopped.")
- o& I3 g6 p* _& q+ x6 r stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) Y2 U, O$ o7 S9 |* ~
crt num-cars$ X- q# R, H$ M! H1 ~: {
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setup-cars
8 F% v. b* p0 U i set-car-color- V% O& j, j6 ~/ r* W( b4 z
record-data+ b7 o* ^4 r3 f; V7 G2 E! c
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$ {% a2 T: x7 b6 {; ` ;; give the turtles an initial speed
# U* S9 ]* l; A& t ask turtles [ set-car-speed ]
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reset-ticks% e0 P1 l5 q6 t. t
end
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y9 N3 p( g4 V, P [;; Initialize the global variables to appropriate values
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: l; ?) g: G$ W set current-light nobody ;; just for now, since there are no lights yet
+ m3 R/ U) i W: p set phase 09 |2 c. K. V4 J' E
set num-cars-stopped 0
8 S' h' R+ h9 I4 I set grid-x-inc world-width / grid-size-x
2 W$ M/ `" m6 w. `8 J# a8 ~1 @ set grid-y-inc world-height / grid-size-y
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1 ^* Y/ Z% d5 ~2 L" L& j3 F! j: Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 F) b# @, a0 L; e# ~6 @: O' G
set acceleration 0.0990 S9 F5 y9 @, V V$ L* }
end; j$ r( ~. J# m2 p8 ~" ~& v
: E8 z7 e4 k" N( O: K* a;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 v2 i! q5 |5 l/ N;; and initialize the traffic lights to one setting) l& F e. |# U( _& s& E6 d
to setup-patches+ Q' z; f+ C5 b# P/ L
;; initialize the patch-owned variables and color the patches to a base-color; q8 F V+ e' t, g; O4 a/ a
ask patches) c# G& C% {7 c8 X9 x
[
, l( A4 g& J, A" J set intersection? false- ]8 `" K/ \6 o% G! x S
set auto? false
# N( b% A4 l3 v" k; S set green-light-up? true) }2 g% B# o: s2 W. T
set my-row -1
- O2 j7 u6 W- a7 D& O set my-column -11 O2 }5 R) [$ E$ T& P
set my-phase -18 k3 [3 k4 F* b+ }/ M1 R
set pcolor brown + 3
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, R4 q1 }1 i5 w1 v" x, Z0 s0 i ;; initialize the global variables that hold patch agentsets+ f7 s* M" L" u5 r" f
set roads patches with
; t4 x" d1 C- u3 \/ @, T! d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 g! q; Q; I$ Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 }( y! d. B. o. Q) F8 P
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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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?
" j' _; X; E! h: {- g+ V set roads patches with7 U; p/ e/ h- F. a6 I2 ]. B* Q* z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 j: i+ A. x9 I* R5 P5 p: A) a. l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' _7 L% g& F" h+ v6 s/ |& ?6 Q
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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