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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。
o2 Z( B- }4 f& onetlogo自带的social science--traffic grid这一例子当中,% p! d' q" U2 B& B8 V3 q2 t' p
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction3 t" N3 P- b6 C
grid-y-inc ;; the amount of patches in between two roads in the y direction
/ a& g) d- y4 B- ]: V5 y acceleration ;; the constant that controls how much a car speeds up or slows down by if
% g" H( v5 k# v. d ;; it is to accelerate or decelerate/ }/ S: f/ h! r( v1 u# G
phase ;; keeps track of the phase- i3 [+ Q% h* `1 n. ^
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 b* H7 e( \. F; ^$ {2 S3 S( {! y7 f& o current-light ;; the currently selected light+ H5 O$ k: W3 z, m% B' w
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;; patch agentsets
3 j3 Y4 t/ s1 U" P2 J; | intersections ;; agentset containing the patches that are intersections
# k( H0 x/ @# b& q5 `2 R roads ;; agentset containing the patches that are roads
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3 P2 @( X. [" U: y( L1 Pturtles-own
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speed ;; the speed of the turtle" r, f7 {7 D. ~" K/ ^7 y" N
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 v5 E, _- S% o ^: u e0 b
wait-time ;; the amount of time since the last time a turtle has moved2 H1 K; s- i/ z- ?3 k8 e! w4 M
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; m3 x4 l. r9 d* hpatches-own+ T! s5 i% w8 D, I
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6 X8 X3 T! l5 e intersection? ;; true if the patch is at the intersection of two roads
0 d* w- v; L. O" g; v; Z# ^! Q green-light-up? ;; true if the green light is above the intersection. otherwise, false./ {7 e7 \0 R: e( o v9 Z
;; false for a non-intersection patches.5 a! i9 a0 O8 V" |
my-row ;; the row of the intersection counting from the upper left corner of the
6 G# C* I1 Q% Y3 ^ ;; world. -1 for non-intersection patches. N# H" a1 h4 j/ Y0 p. ]
my-column ;; the column of the intersection counting from the upper left corner of the0 K. p6 f$ U6 r2 |, t+ i
;; world. -1 for non-intersection patches.8 t {2 q2 j5 q
my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ J. W2 c) Q9 c0 Z/ ^
auto? ;; whether or not this intersection will switch automatically." \9 r) A' t+ q+ M
;; false for non-intersection patches.
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; T3 Z5 y/ m+ P2 u# X$ q, v3 j;;;;;;;;;;;;;;;;;;;;;;9 d, _2 m6 G, c* `- Y6 x3 |2 }
;; Setup Procedures ;;% I4 [. d3 ^. U6 g
;;;;;;;;;;;;;;;;;;;;;;
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; Q! M, q4 Y( O. U8 N7 i;; Initialize the display by giving the global and patch variables initial values." [1 A4 l2 Y( M0 d1 h6 `
;; Create num-cars of turtles if there are enough road patches for one turtle to0 s F" D) u4 M& {* O( J+ A3 y
;; be created per road patch. Set up the plots." j, E# x+ ` n
to setup
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" C! o) H7 d( z setup-globals
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7 R! n, s' z9 W) I7 d ;; First we ask the patches to draw themselves and set up a few variables6 K% \3 w! L7 n! f5 v( Y5 m3 e
setup-patches3 n% Y, i, @+ M$ K) U4 \
make-current one-of intersections
! ?3 x" M8 a& k label-current
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set-default-shape turtles "car"& j( c3 Y! |* v6 ?* i0 {: P1 s
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ") j' d6 }! \) R) k! t
"road. Either increase the amount of roads " N5 W3 ?( M1 K" _' p, J2 A
"by increasing the GRID-SIZE-X or ", ^, j' q8 Q+ Q2 g* m
"GRID-SIZE-Y sliders, or decrease the "2 D( J2 A8 @* e* c
"number of cars by lowering the NUMBER slider.\n"
+ m# ?, ^! R. u1 C8 X "The setup has stopped.")( ?: E1 Z* H$ m
stop
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) f2 E# r- @# W+ I9 t ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. J) ?" q0 ~0 R crt num-cars
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# b, N8 R9 f% T: D7 |! O2 i: T. B setup-cars
9 q+ k* z- M6 X# D4 A d set-car-color
; x% ~. N. ~3 I( m' S. b* a! n record-data
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;; give the turtles an initial speed; a, V1 v0 q. D7 z* J* z
ask turtles [ set-car-speed ]
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. b( E; ~2 c( \9 i6 s7 i reset-ticks2 G2 G2 Z' a Q4 [' N
end1 k7 ]. k6 f7 F- G1 [% o
# \7 n/ u! X6 A2 J0 J;; Initialize the global variables to appropriate values9 H& q n1 d9 j& S, ^. \9 X
to setup-globals/ y9 B- ]" a0 R* |' B h
set current-light nobody ;; just for now, since there are no lights yet
) l+ b N" _4 C @+ q/ ? set phase 07 @* ^$ [1 X- [& i
set num-cars-stopped 0. I, w' H0 e3 [8 ?$ }2 O
set grid-x-inc world-width / grid-size-x
6 V: L, ?" b+ E8 y set grid-y-inc world-height / grid-size-y
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# {" r" ]9 r& B2 E! v$ E. i, C) q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
7 p! f7 v" f- d7 H set acceleration 0.099) w0 o7 m* f4 f" A
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 `/ v9 ?) t; f3 E0 {$ \
;; and initialize the traffic lights to one setting
$ R T$ \/ N& p2 [to setup-patches
0 O/ l7 V/ D' u a# \ ;; initialize the patch-owned variables and color the patches to a base-color+ V# `: o0 M; T# c9 w
ask patches X" @$ R/ f3 Z3 S3 \1 G& Z8 M
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set intersection? false
?* X& ]7 ^# g set auto? false
& t' X; b J1 y) H0 U- e+ i. n. Z set green-light-up? true( m/ s0 T. S$ K8 h: U
set my-row -1
' l' a/ U% X8 i z( R1 T' s set my-column -16 D1 a. Q6 [- y X
set my-phase -1
+ V) I2 M9 {6 @4 p; n set pcolor brown + 3' S! I% u5 M* Y. {7 |7 g
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;; initialize the global variables that hold patch agentsets- c. {, }& k: _* H7 ?2 @
set roads patches with
, r. @: q. K5 m8 y' [4 ?: t/ F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 D* W3 I$ d. r7 W: S6 v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! P2 e; A2 y: x0 C: s: y0 M set intersections roads with
% c& g0 }9 G. S) D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- t$ |$ a& }) V& A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 c. I' E' \2 y( j- K% W$ M
" [' e4 e% a! W1 A& p5 q! G 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?
6 e; O# f" A0 s- v; v set roads patches with( Q/ w/ D0 S! F' U% L/ \$ \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 |8 _% ?/ J" J, D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 R: `; Y! b1 O a1 u( ~
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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