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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。- r5 E( N: {; t/ S, h% B6 H: j
netlogo自带的social science--traffic grid这一例子当中,
5 g% o/ r x D# r) G, \" u; @6 dglobals
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- N& N: o8 k) ]" j9 C0 X grid-x-inc ;; the amount of patches in between two roads in the x direction* g6 m5 s% W( p7 g0 T& c9 Y) u8 k0 ], K
grid-y-inc ;; the amount of patches in between two roads in the y direction
( j' {" m' W4 b' z0 y/ U3 D) J! k acceleration ;; the constant that controls how much a car speeds up or slows down by if
# d0 m- [4 U4 ]. V ;; it is to accelerate or decelerate
/ N- }5 b1 Y' l6 [ m8 a phase ;; keeps track of the phase
( k' D Q! L$ a# M num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 y' `# X! F1 B7 }0 ^: L4 i" S8 L
current-light ;; the currently selected light
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;; patch agentsets
4 W1 o' k9 ?+ a: t7 a intersections ;; agentset containing the patches that are intersections2 ~$ h6 a! K, R+ s+ G( E
roads ;; agentset containing the patches that are roads# L2 {1 `3 b9 {7 [
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turtles-own ^# J) h+ }; j! Q8 u! q" N0 f3 r
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speed ;; the speed of the turtle( i* c6 b: i* k& e. [$ T
up-car? ;; true if the turtle moves downwards and false if it moves to the right y! I5 s6 Q0 U( b5 I
wait-time ;; the amount of time since the last time a turtle has moved9 t& n! `$ Y3 C( D
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& [7 @! f/ n$ @5 ?$ v, t$ q! j7 vpatches-own8 P' G- I9 o/ r# ?( [
[) [5 ]) } S% a& P9 w
intersection? ;; true if the patch is at the intersection of two roads
6 G6 ]% v6 C5 o5 l2 R9 h7 l green-light-up? ;; true if the green light is above the intersection. otherwise, false.; u% j, I( J' l
;; false for a non-intersection patches.
7 i# ^ B! L9 R" K my-row ;; the row of the intersection counting from the upper left corner of the
. s/ K( ^( m5 R) n$ @/ l# [ ;; world. -1 for non-intersection patches.% N1 v) A1 ]7 ]7 b* Y, e4 i
my-column ;; the column of the intersection counting from the upper left corner of the* f* V7 B% }1 t0 h! \9 `7 N
;; world. -1 for non-intersection patches.
' B9 X5 J8 e5 |( c my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( B( ^, d Z2 Y6 @6 ]+ v auto? ;; whether or not this intersection will switch automatically.
O2 ~0 i. x$ K- j ;; false for non-intersection patches.& v# F6 F, z( R( @& B
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% q- a3 @; D) j: {;;;;;;;;;;;;;;;;;;;;;;
, [$ h, Y$ ]- M;; Setup Procedures ;;
1 R- b2 H1 i7 \; [3 ]5 F;;;;;;;;;;;;;;;;;;;;;;4 j/ O) A/ k% ~! Z
# z. ?( q$ i/ m c
;; Initialize the display by giving the global and patch variables initial values.
* c' R3 V8 n7 L# W7 N;; Create num-cars of turtles if there are enough road patches for one turtle to3 W, z, ?. f, R
;; be created per road patch. Set up the plots.& L6 L/ ^# G I; t; ]7 E
to setup
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) y1 h5 Y# n! W. C2 B setup-globals
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) @4 J/ u/ O; Q7 f3 o9 e' H2 k+ C) L ;; First we ask the patches to draw themselves and set up a few variables2 X6 ?# M4 a. f& M
setup-patches
' q, i: Q. n( J( t& t- s) A make-current one-of intersections! q. Z. q0 Z$ j2 I/ M) G
label-current
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1 k1 g- f9 ]1 @1 ]: ? set-default-shape turtles "car"
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$ s. z; F' z3 I, l* n5 h/ p3 X if (num-cars > count roads)
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; l9 n& P, W( J9 D# m f user-message (word "There are too many cars for the amount of "' x: P# @4 E' y S9 @
"road. Either increase the amount of roads "
) A# Y& O0 i# Y O, m7 S "by increasing the GRID-SIZE-X or "
, ]7 \7 d* \$ k! `7 ` "GRID-SIZE-Y sliders, or decrease the ". |" q: [7 K8 @6 U
"number of cars by lowering the NUMBER slider.\n"7 Y5 F$ m. `7 M! Y9 o/ c0 x
"The setup has stopped.")
6 C- [* x/ j2 G5 X stop
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. }4 I8 i# w6 J" K6 |" Q: ?4 Y( G ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& P1 D" G$ q/ q; }/ i- y1 X crt num-cars1 S- G2 X `2 M# M$ Q
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setup-cars( X; T, q. I3 s. J. l u
set-car-color
6 a! R% w$ T: v0 R record-data
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/ I6 F* {( m& v M f5 l* l- h ;; give the turtles an initial speed
* R+ @: Z* @0 B: i ask turtles [ set-car-speed ]. e* O5 ]4 h8 G8 M* B! h
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reset-ticks& z& n# J- p& F* B8 n7 y
end7 O5 u) }: p/ ^5 z) ~" v1 W& s
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;; Initialize the global variables to appropriate values
! x4 `7 ~" t# \; I7 H! T+ Hto setup-globals
: Q! Y$ k9 J; E/ J; ? set current-light nobody ;; just for now, since there are no lights yet# n# c, h; w0 R1 V, w
set phase 0( V$ a6 S) n! ?/ |& D6 ^
set num-cars-stopped 04 y/ }! F9 b5 l; ~! o' ^2 T% x
set grid-x-inc world-width / grid-size-x! q- x& i5 ]3 P* e. j
set grid-y-inc world-height / grid-size-y3 P% _$ [; k* ~# z2 B
" J% A5 h9 U' O1 j- L* f ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: @# C: l9 }: y3 M8 Y2 S9 l set acceleration 0.099
X% m4 n6 `% t8 u! Z$ |end; O# o3 r% v9 E- d
s1 w1 d8 w8 P- k* q4 z7 m;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# J6 Z# p* K, N% Y5 s5 Q;; and initialize the traffic lights to one setting
, a" D% \+ v$ y; l$ d. Uto setup-patches4 ~, `/ [# ]# f I
;; initialize the patch-owned variables and color the patches to a base-color
+ j4 d8 x1 B: I/ @' e9 m- O ask patches
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set intersection? false6 L, r! v, Q- b$ B1 U) {; g9 {
set auto? false
# D2 y0 P1 `4 j% n set green-light-up? true4 @/ D2 J4 `/ n
set my-row -1) M4 j6 D1 v0 ~) j
set my-column -15 Z, J; y `1 o' i! u+ W
set my-phase -1! \% X( I* S$ p Y1 z2 t
set pcolor brown + 3( t/ n' p" H& T3 x" ?" F% H
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; x3 N O7 B$ b- l ;; initialize the global variables that hold patch agentsets
+ f3 |0 ^8 ]/ [ k2 s! Y set roads patches with8 @" D+ C" W+ c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% T7 c3 G5 |# O7 \+ ?1 W$ l; v$ ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 E5 b% s4 ~+ V2 o9 Z2 e" j$ h
set intersections roads with
2 }$ T( d( ~, Q9 N" q$ S e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 E' z. p: |! r. `: e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# |; n! P" ], U9 y
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ask roads [ set pcolor white ]: Q, [ I$ f% o5 v, R/ ^& i2 Q
setup-intersections% m! U- j) r9 ]9 y- W
end
* {0 e# c- c! L a, n其中定义道路的句子,如下所示,是什么意思啊?
& Y i- l9 Z+ Y7 t% G, J! @, m) u set roads patches with
: T2 F7 _3 y0 Y4 _( G& l1 ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! j) T0 n) g" d( F9 A; C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ p+ \' `9 v4 v8 a9 i! f5 F" z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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