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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。
: m' G- @" n* d5 F6 ~* p: ^netlogo自带的social science--traffic grid这一例子当中,/ A! e' p# {3 t, N& N2 W
globals$ ]) i6 [% H* l
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; D2 A) |2 e+ P grid-x-inc ;; the amount of patches in between two roads in the x direction
5 v- t6 u% l. H8 v grid-y-inc ;; the amount of patches in between two roads in the y direction
; }) u) Z% h8 M acceleration ;; the constant that controls how much a car speeds up or slows down by if0 X1 `2 Y, n' d4 G
;; it is to accelerate or decelerate7 _& ]4 ~, N4 Q: f1 B
phase ;; keeps track of the phase
6 _% ~! I$ c$ i; ~1 Y4 u" b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# p$ {2 @! g+ I# L( b current-light ;; the currently selected light( ~1 K+ @* ]+ t \0 y# e" O
1 q# Z# p6 c U$ j ;; patch agentsets
* x3 l3 f- o7 _$ s intersections ;; agentset containing the patches that are intersections
. d% v- t* t" E: W; c9 g roads ;; agentset containing the patches that are roads
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" Q& h5 I B }5 Y- Cturtles-own
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speed ;; the speed of the turtle
( n! T( `3 X: U! v N" J2 m4 [ up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ i% O7 L) [) b+ Y0 U 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) R! a, m' c* Q, p
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 m9 Y7 V Y' x: v; y% W; U ;; false for a non-intersection patches.; v: A0 z/ f$ @; s+ Y
my-row ;; the row of the intersection counting from the upper left corner of the9 s6 f. P& D0 u. z- C0 j+ `9 n( p
;; world. -1 for non-intersection patches.* n- Q0 ]- c% k# g
my-column ;; the column of the intersection counting from the upper left corner of the$ O2 ~8 i' e+ c
;; world. -1 for non-intersection patches.8 y0 _% C" I/ ^) k9 a. m
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, z$ A! g0 }( s5 m, P! N6 U0 P auto? ;; whether or not this intersection will switch automatically.
! p6 L! Y* o4 M) r$ u ;; false for non-intersection patches.& v6 x2 x, i9 g$ J+ I
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( x- l: f" T3 p" ~7 i;;;;;;;;;;;;;;;;;;;;;;
6 M2 e# U* g$ x8 i) {, H;; Setup Procedures ;;6 Q- d. a1 Y' I0 u9 r0 r7 ^! }6 S7 A$ J
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
) ]( O- B, \0 p- v& f3 k3 D+ G;; Create num-cars of turtles if there are enough road patches for one turtle to
9 o* N0 j* I! a1 u7 I5 y;; be created per road patch. Set up the plots.
0 v& t7 {! B h: S) F0 |to setup! \# T! t3 p1 I! h. k- q# Z8 _4 C
ca
. D" j- v* G. t7 D# `1 [ setup-globals
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0 f% b( d, A) K3 K5 \7 B' J ;; First we ask the patches to draw themselves and set up a few variables& E- n2 C# g1 L+ G; x$ t% i% @/ F
setup-patches. Y/ R5 z$ [- e9 Y+ S- Y
make-current one-of intersections6 f1 Z7 |" w2 }$ U2 |& t
label-current, o. r3 m! R9 a% g( F; Y4 n
" z# [. l8 A; U# h g set-default-shape turtles "car"
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if (num-cars > count roads)
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3 u% O' S8 U, {0 G1 y user-message (word "There are too many cars for the amount of "; o. Z1 Q7 j6 Y9 W+ y9 ?; `2 {" K
"road. Either increase the amount of roads "
! r! f5 a# [" K& C. U5 M: { "by increasing the GRID-SIZE-X or ": U" ~- A5 U6 b4 n. K5 T
"GRID-SIZE-Y sliders, or decrease the "* _# L9 Y2 p1 n9 _& h
"number of cars by lowering the NUMBER slider.\n"
" [3 D& c+ R6 C. i4 a& c+ [0 O( k "The setup has stopped.")) n0 h& \$ n6 q& g) \* m
stop7 q. y) V+ [/ y C1 C; R$ @
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% k* M7 Y* E6 @: J8 K+ J9 M( W crt num-cars
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setup-cars' {; }1 |# F7 g- E, t) y! n
set-car-color
3 K; G; Z3 _1 z. X' S# E/ l record-data
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;; give the turtles an initial speed
5 @( x3 X$ u/ ]7 b, k ask turtles [ set-car-speed ]
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reset-ticks, x) C O q+ C$ c, ^
end
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;; Initialize the global variables to appropriate values
6 I4 D( t1 R8 u- pto setup-globals
8 K' ~6 {, R7 J set current-light nobody ;; just for now, since there are no lights yet' D4 K6 o! o8 m+ C6 k0 j! O
set phase 0
8 [+ E9 l' P4 _% |0 G3 ` set num-cars-stopped 0
! k- o! }. J! b, w" I set grid-x-inc world-width / grid-size-x
" O( s- S" p/ E" A- K set grid-y-inc world-height / grid-size-y: \* _& a9 ^6 x7 }
& C' W4 |1 S, i/ i# ^6 `$ { ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary# O1 w) D* d0 Y% S" _ v
set acceleration 0.099/ {* V0 ~4 t$ B# c5 f! ~ [+ p
end* ~ x" w& {. a' R# X+ n
3 I2 j) `1 U) `;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ t9 m8 }; X5 c;; and initialize the traffic lights to one setting
) O# P9 [1 a5 ?+ tto setup-patches
+ q$ S p8 M* R5 B2 O4 T ;; initialize the patch-owned variables and color the patches to a base-color! T: {' J0 w' R
ask patches9 q( ?: v( g$ ^0 O
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- A6 C* x) g- A2 X: c set intersection? false
9 \8 p. h# x" h) v! p6 ?% e set auto? false
7 Y( m; e9 J% K6 j8 _, o5 q5 g set green-light-up? true
6 h0 y" ]% u$ q$ T ]1 K set my-row -1- S7 m$ G2 c4 `' h
set my-column -1
1 h* M: G" u' w% f) I7 i set my-phase -1
. U* W. I+ k8 g. _7 C% t set pcolor brown + 39 T. O3 q4 d* Q
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7 x# N0 [+ G8 Q7 y/ l7 k/ t ;; initialize the global variables that hold patch agentsets7 B4 \8 e' q3 h* H: g8 o j% e
set roads patches with
6 ~' E: G# b6 E, |; U. E6 U6 k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' K3 R: ^2 D+ y- b! y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% ]# l; t1 l4 I# p# W" T
set intersections roads with
) c* l' n' C% A# z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 [& X- N/ o, o( A+ U1 O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]1 S$ N4 P% O/ d9 x% r0 u, b
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
: ^& {9 p D& n* v$ _6 G set roads patches with
. T- G" W4 _6 E6 N, B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 o# Y, A8 X+ b9 T: x: P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ i) s% [+ S; @' j( D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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