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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。3 ^, G" R- v. b$ T2 ]. a( @& d1 n
netlogo自带的social science--traffic grid这一例子当中,
9 D+ A, M6 L- t# M$ B: i' |globals
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! m3 m) K; v# a0 T. b grid-x-inc ;; the amount of patches in between two roads in the x direction/ n, O2 k; P, C9 k- m4 ` ~+ c' x* U
grid-y-inc ;; the amount of patches in between two roads in the y direction
" B/ m+ i3 L; X2 u acceleration ;; the constant that controls how much a car speeds up or slows down by if
. X8 ]6 G, B! ? ;; it is to accelerate or decelerate
* h4 a" D8 y. {! w: { phase ;; keeps track of the phase
?5 w& U' _, A2 r num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, j4 ? j4 g/ e; n# h0 H- ]# f8 b current-light ;; the currently selected light
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;; patch agentsets
3 o% _: g4 _2 G2 ? intersections ;; agentset containing the patches that are intersections7 T5 v- o* W( z1 O) s6 d$ x5 D
roads ;; agentset containing the patches that are roads1 B8 |8 G8 ]+ A$ P
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9 s' ]6 |; x- fturtles-own
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; m9 C9 k3 D4 c speed ;; the speed of the turtle
2 b. ?9 g# }7 q- v1 P0 ] up-car? ;; true if the turtle moves downwards and false if it moves to the right5 R6 T) K8 n8 ~! ?7 E
wait-time ;; the amount of time since the last time a turtle has moved" D+ ]" Q% F) E8 [# Q7 w
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! Q: i9 C7 `6 t) [/ B% X. fpatches-own& K; x( F) d: y: U
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9 H9 w* q8 W7 K/ u, ~- P8 [ intersection? ;; true if the patch is at the intersection of two roads
( `4 Y3 \& t$ a1 [ green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 o( Q7 | l2 @! D. D
;; false for a non-intersection patches.5 V" U- C# c( ?2 \% Z. v) `
my-row ;; the row of the intersection counting from the upper left corner of the$ @4 e. `7 v; h# ]( B
;; world. -1 for non-intersection patches.8 x, q8 O* _5 }0 w9 ~6 d
my-column ;; the column of the intersection counting from the upper left corner of the1 Q' p6 O" j# g6 b7 d
;; world. -1 for non-intersection patches.% ]( q) ^! N: O. [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.# g3 s7 r8 ]- Y
auto? ;; whether or not this intersection will switch automatically.8 L/ p. r+ l2 @ ^
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
" s4 s* {" k" P% K; {: C* p& m F;; Setup Procedures ;;
5 U& S: k. ^7 u W6 s" k% A;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
2 q4 E2 k, U, N4 v+ o;; Create num-cars of turtles if there are enough road patches for one turtle to$ }8 |; o- ?. D1 k$ T9 E M5 D
;; be created per road patch. Set up the plots.
' B# G2 X/ t' V, hto setup
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4 f# s# |% H6 t) ] setup-globals
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2 s, |8 h/ E4 l" I8 B ;; First we ask the patches to draw themselves and set up a few variables/ h0 W. W# H2 A: s4 }
setup-patches
0 i, [. z' @! N% N4 j! C- G8 D8 r" _ make-current one-of intersections
( r# k3 y, p4 M! H/ H# A label-current7 p7 E3 C0 y; e1 t; l
. D; E! z& L7 P/ h set-default-shape turtles "car"
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* h5 _5 Q) c0 b' c" _/ L if (num-cars > count roads)) p% A, } @( b. ]5 D
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user-message (word "There are too many cars for the amount of "2 L- n6 M0 D/ ~1 }. ?, f! l
"road. Either increase the amount of roads "
3 B+ h N0 P) [6 E "by increasing the GRID-SIZE-X or ") g/ q' |4 _- m1 C! f
"GRID-SIZE-Y sliders, or decrease the "
" l! {3 }- [1 V$ w Q2 A "number of cars by lowering the NUMBER slider.\n"
% d; K/ Z% C& H4 t* L6 U "The setup has stopped."): x3 G8 t- Y/ \6 Y
stop+ M1 h% B y5 n8 t$ P) p
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
; _3 d5 r3 c6 d4 ~ crt num-cars. \, W4 H2 _8 b% |* C2 h- x
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setup-cars, P- o+ K: T" j3 F/ w9 e
set-car-color
& b+ B2 o; [5 B record-data
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- L+ p c" r! N7 l% g0 o; P/ h- n ;; give the turtles an initial speed
. R2 C& B0 P2 X ask turtles [ set-car-speed ]
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reset-ticks# o2 b* T7 J) K+ V% `3 C7 s/ q
end( [$ E+ _8 H0 Y& t
( M( z% c: k+ } P$ P;; Initialize the global variables to appropriate values
; v4 o2 `4 Q1 e0 Yto setup-globals
8 j$ f6 Y- K( d/ ^; s8 E! c1 K9 f! M set current-light nobody ;; just for now, since there are no lights yet
k5 V3 K3 b0 X- N. x* n set phase 0: N6 s9 `/ q# J* I% r8 B& x
set num-cars-stopped 0
+ e0 s$ d3 o) G" l, R6 D1 T5 w set grid-x-inc world-width / grid-size-x
; ?8 }9 Q1 I5 e S set grid-y-inc world-height / grid-size-y( W! \+ u, b4 h" T" E" W4 o0 y5 X! \
' U* x I# \4 @- Z! p- o9 k# R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! O. Y5 f$ d) b; D, h set acceleration 0.099" ]8 t* ^ V- \- g
end
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& g6 l! V; j; B! B1 l/ l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 h! L9 }( {" G, C7 X
;; and initialize the traffic lights to one setting
0 I- J6 n' |8 G% j2 V3 p3 V% oto setup-patches+ d( |2 D7 m9 u* ?+ C) X# I
;; initialize the patch-owned variables and color the patches to a base-color
% |( ]1 P9 ~: B8 ?" Z1 }# K ask patches
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' h( R9 o3 v& G/ @2 O5 T4 e5 R set intersection? false( a6 b, B; E" O" g2 h0 P* [
set auto? false$ B( E0 K9 Q' P
set green-light-up? true
! L6 m" w. I7 X2 S d set my-row -1
8 X K( }" _$ f0 e set my-column -1) P e& R8 n3 ?1 S9 C: V
set my-phase -1
" O( \ h# }: V" p/ G: W set pcolor brown + 33 @6 v# O6 o, a3 i8 i7 g8 ~. U0 [
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5 q# C5 x8 \/ c/ m3 h5 u ;; initialize the global variables that hold patch agentsets
$ y: Y$ L$ T$ B D" n0 }# O set roads patches with
+ G6 E8 p* N: t) C: \9 N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 Y3 Z0 p" t2 d) \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 p6 s3 f: P; p
set intersections roads with' n# c: z- K+ C4 {! A/ q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% @1 z p5 M$ P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" a; H l) X4 v+ |9 o
: t7 l7 ?( F N4 t ask roads [ set pcolor white ]
6 f: i1 |& s8 H) o4 f& x* m6 I setup-intersections) b8 D# H0 v& Z" Q3 O" v
end( ~) }6 ?8 U( e* c. p# S
其中定义道路的句子,如下所示,是什么意思啊?
6 h: x7 q( U( }" o# F% r5 Q set roads patches with
5 U1 n, ?0 f! W- [7 t) T/ d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& ?8 C1 v5 ?$ c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# s3 s# M" Q5 h, m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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