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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。8 y b% A8 o5 F' ?
netlogo自带的social science--traffic grid这一例子当中,* U- ]% R. M! q# j0 n* l1 p N) b6 j% J: F
globals
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) k- h0 k- Y1 o; |: ?! F# M$ i h grid-x-inc ;; the amount of patches in between two roads in the x direction
: H6 Z$ Q1 ^$ A/ I2 w: r grid-y-inc ;; the amount of patches in between two roads in the y direction* Y' t$ q! y, k9 X5 D
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 K+ |3 S9 k; A# r ;; it is to accelerate or decelerate$ V+ W3 Q. Q9 D) l. g
phase ;; keeps track of the phase
) p; H' _' d5 ~2 r0 ` num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! d/ r" ~6 Y4 e2 _' F: Q5 W# ` current-light ;; the currently selected light
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;; patch agentsets! r" f. D+ y/ [: L; c% m4 h
intersections ;; agentset containing the patches that are intersections
( ~$ x7 f+ ^5 e: w$ o z5 C* ] roads ;; agentset containing the patches that are roads4 p+ T5 I# H9 X6 P, B7 S, A! v
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turtles-own& x% n) X+ `2 }: L7 D
[
8 Z, [+ h$ v$ W" W5 O$ Q speed ;; the speed of the turtle
7 Y# x+ c* r7 O. K1 Z up-car? ;; true if the turtle moves downwards and false if it moves to the right
% W! J; k9 z. x! b! ]; L4 c7 A! c wait-time ;; the amount of time since the last time a turtle has moved# t' c+ j' @' f$ v7 }# `
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patches-own
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$ @% d/ F0 x7 z; r4 r' n intersection? ;; true if the patch is at the intersection of two roads' ]+ W Q; t" |" b; \. H) F4 w
green-light-up? ;; true if the green light is above the intersection. otherwise, false.( J( c% g- a, J+ x
;; false for a non-intersection patches.
! J* v# A, D9 Z p# C my-row ;; the row of the intersection counting from the upper left corner of the
# w! [3 y7 x- R ;; world. -1 for non-intersection patches.( S. a- O3 ]/ {! q- m9 A
my-column ;; the column of the intersection counting from the upper left corner of the, T' c" B2 x1 H) w: z7 z
;; world. -1 for non-intersection patches.
4 j3 h7 [. W9 \0 W# G( D my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 E0 Z. D! Z3 {" ~9 S0 F% b6 v auto? ;; whether or not this intersection will switch automatically.
/ `/ Y0 K, g! i$ A% [) W0 ~: X ;; false for non-intersection patches.
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2 L! A$ P- M, P, j+ _9 e;;;;;;;;;;;;;;;;;;;;;;; {1 Q0 n& {3 ^; H* N* R3 ~
;; Setup Procedures ;;
( l: x# {; B4 l$ v3 z5 n;;;;;;;;;;;;;;;;;;;;;;
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+ J' H+ q) U! t Y;; Initialize the display by giving the global and patch variables initial values.
+ Z _- L5 l6 i0 Z6 r- ^1 p. f;; Create num-cars of turtles if there are enough road patches for one turtle to! _: v ]9 n- e. \: h) d& d
;; be created per road patch. Set up the plots.9 O7 r' w& Q5 i1 G- W' G) Q8 o
to setup5 R/ e- o4 n. a' v: ~) b
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setup-globals& y- {0 `6 L1 V* O% M& }
4 j0 s3 b0 C) \# R" k' g/ P1 k ;; First we ask the patches to draw themselves and set up a few variables0 U, s% \, F1 d( n& \+ K+ W2 @4 B& d
setup-patches1 y& T' o- ^" N# P" z N" P
make-current one-of intersections
, h4 a, T P/ n( }0 t label-current* Z3 z' v1 S0 k% ]9 T5 S& G
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set-default-shape turtles "car"4 k; ?2 i0 v& b, M. ~5 O- q
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if (num-cars > count roads)0 ]% O0 J t% s% [0 k/ s
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user-message (word "There are too many cars for the amount of " @' }: f F H/ V, s; H( {
"road. Either increase the amount of roads ", {! q. |+ [3 w' P8 h
"by increasing the GRID-SIZE-X or "# m% G& e; r% k! J; F: {
"GRID-SIZE-Y sliders, or decrease the "9 x* q) Z4 B- N$ M: |
"number of cars by lowering the NUMBER slider.\n"
: H. c9 ^! s7 k0 |5 ]& L) V "The setup has stopped.")
, _1 C- @; |( H. l. ` t stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 w5 G1 e0 f, _% |: }4 A6 M1 K
crt num-cars# r! [( V- W0 H9 O
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setup-cars
0 q! @3 m2 U: s0 B! A set-car-color7 k$ Z$ a! L/ J7 \' v
record-data2 { S3 p; t2 g' k- p) ~" x
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;; give the turtles an initial speed
3 {( w& w+ _. ?& V ask turtles [ set-car-speed ]3 k* f9 x7 L7 ~* n2 {
* B9 W& u. q1 x5 b* h reset-ticks- @- X( w' S2 l; I
end
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# S% V: N, M; L, x1 o+ f3 s- o;; Initialize the global variables to appropriate values
/ r3 |* u% t4 u+ lto setup-globals& d1 U9 J: ^6 N9 O
set current-light nobody ;; just for now, since there are no lights yet
: ?, g! ~. T& S9 d set phase 04 U! s& a( c$ c2 q- y0 L0 Q6 _- m
set num-cars-stopped 0
6 q" \/ r) u% W set grid-x-inc world-width / grid-size-x
+ ?6 O$ ^2 l2 P' ^, h/ o set grid-y-inc world-height / grid-size-y
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$ U/ ^$ Z/ Z' D7 I- V* r. ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) P6 p( G3 i+ |4 ] set acceleration 0.099* ~9 e6 O" H: A; z
end8 H1 h1 F- p7 X0 j+ c! g
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 A) p8 g4 E. [;; and initialize the traffic lights to one setting7 p1 u! T I$ d/ E
to setup-patches
, R+ p- \ n& f- i4 i- u% I- q, j a ;; initialize the patch-owned variables and color the patches to a base-color
7 y6 {) f A% ]; F! |7 | ask patches
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! N( x- V0 }2 q# Q set intersection? false
5 L- Q" s* V" X* B" B V5 t set auto? false5 U, i$ u- R) Q. y) @+ x
set green-light-up? true3 p3 o; b1 r% g$ p0 d9 U0 v
set my-row -1
6 J" r3 Z. ?! d0 Q set my-column -1$ U7 }6 B/ H" h6 Y8 f @, ~8 M% {' w
set my-phase -1
1 h8 y2 N+ D* G" `+ p0 u set pcolor brown + 3$ E- v- S& N v: F) L
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7 x) p8 Q! Y0 i( A6 R& a ;; initialize the global variables that hold patch agentsets! H" ~+ j. T5 s8 g" _6 Y. y9 Y
set roads patches with
+ O$ `( B: p4 e9 ?9 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! N! |; e D) i' \, [; a1 m3 ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ i4 ]" Z6 ^ a' h+ O
set intersections roads with
% |% J: w' H0 E. E/ A0 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ p- t+ Y+ C1 r( j, I' n (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' k) C/ ]: ^1 d- r z0 G
D+ |7 M; d. {8 _$ C; z ask roads [ set pcolor white ]
( l2 m( z3 P9 f0 g+ ] setup-intersections# Z* v& t' S6 l& n/ N
end
4 I# C$ V- ?: @3 @. s( q其中定义道路的句子,如下所示,是什么意思啊?
; P! e+ }" B( g/ Y, J set roads patches with
F/ b2 k5 D0 R8 F9 k% U5 O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 J' y' g% r: v: T0 Z6 H. Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 j7 k3 |' y, \; v1 }4 _- 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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