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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 ^9 H' ^( B' S3 A$ }
netlogo自带的social science--traffic grid这一例子当中,
# D7 ?/ C" V1 K' a! vglobals
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* q3 d& V+ u) E( W! ?8 q$ p0 x grid-x-inc ;; the amount of patches in between two roads in the x direction
5 E7 {' l$ y! Y grid-y-inc ;; the amount of patches in between two roads in the y direction1 M" c, V# c$ `4 v8 w/ U" g
acceleration ;; the constant that controls how much a car speeds up or slows down by if9 T; f% O. U" M3 l% R* B( S# @- _
;; it is to accelerate or decelerate
4 ^' u f8 v- l1 Y phase ;; keeps track of the phase
3 W; G! q5 H1 _( F% ?4 ~) t. N num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 _% w3 D8 S5 Z' @# M; O: A5 x o, F4 t
current-light ;; the currently selected light3 b9 I8 j G; C; p
C) r/ M% W5 {2 V; k& s( A ;; patch agentsets
( L1 d* V, `; j' c9 `' n8 B intersections ;; agentset containing the patches that are intersections
4 ?6 Y( v/ X1 P: K. R roads ;; agentset containing the patches that are roads1 \9 w4 R: C6 J& i" _
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, p, C, N$ y% ?7 @& G gturtles-own+ D' M+ G* ]) ~( @
[
' |; c; h- r7 u2 ]+ z1 B9 I2 Q speed ;; the speed of the turtle
2 T5 s# s! f7 U3 A4 d* B E: m: y up-car? ;; true if the turtle moves downwards and false if it moves to the right* v& ^' v" S3 O, {/ e+ q
wait-time ;; the amount of time since the last time a turtle has moved8 B; Y: j: S: g, t
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patches-own
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( U" C' i+ \+ @5 K) W intersection? ;; true if the patch is at the intersection of two roads
* d" e, ~; |! L9 C green-light-up? ;; true if the green light is above the intersection. otherwise, false.& L+ D8 \7 K0 L$ A. v: G2 W
;; false for a non-intersection patches.
8 q* Z2 K8 j* p0 x; j my-row ;; the row of the intersection counting from the upper left corner of the
, X! a z$ q0 k+ Y4 @ ;; world. -1 for non-intersection patches.
. a% k; I! t# X+ Z) ^ my-column ;; the column of the intersection counting from the upper left corner of the% ]0 a" ]" }$ G% f' `' e& a" w# S& e
;; world. -1 for non-intersection patches.
: w# Z! q( X; D4 k1 Q% G" j# c) ~ my-phase ;; the phase for the intersection. -1 for non-intersection patches.& R5 B$ ?( Q* B" v$ g& N. L8 M
auto? ;; whether or not this intersection will switch automatically.: T) F8 t: U! P# e0 O* L2 K
;; false for non-intersection patches.# A7 s% K! i* A
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( Q4 V: d% F* Y' I! |9 @$ u;;;;;;;;;;;;;;;;;;;;;;( @& w" L( v' d: i
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
$ Y, C" R/ A5 R6 J4 D;; Create num-cars of turtles if there are enough road patches for one turtle to1 m3 n, x: b9 P
;; be created per road patch. Set up the plots.
3 @4 d2 @1 @4 h% {to setup$ v; O# N$ A4 o4 S0 @
ca
* T1 w0 m% k( {, f" C0 e setup-globals9 X7 ^1 l0 U! D3 Y) Y+ E
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;; First we ask the patches to draw themselves and set up a few variables& G5 e) B/ O, E
setup-patches
% q) F, c& X$ |* ?# G make-current one-of intersections
% H' U9 ~; @! L) y# u/ s, I label-current
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set-default-shape turtles "car"
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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 "
0 G2 N2 Y" D" R9 p( W "road. Either increase the amount of roads "- A9 @7 `. l+ O/ d. }% G
"by increasing the GRID-SIZE-X or "
) e6 L* ^; {$ m. P "GRID-SIZE-Y sliders, or decrease the "6 b3 _: I9 F2 C: y
"number of cars by lowering the NUMBER slider.\n"5 `( }+ X/ Y6 h6 Q0 q6 \' e
"The setup has stopped.")" O: c( U3 R# Z
stop
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# l3 e! j* Y/ x- p3 s3 r# B ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" f! G6 m [' J& ^# [* ?1 n+ Q
crt num-cars. F; S, X L/ e! | k9 V
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& Y6 n9 x3 a: F* K3 W setup-cars
2 n; z |+ q0 z, n2 T; t9 V `: \% c+ ` set-car-color
7 T1 c: n, q* J$ D h3 m record-data) G! R0 _* ]" X: f5 E$ }7 b- c
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;; give the turtles an initial speed
2 {/ U3 k8 r+ H ask turtles [ set-car-speed ]
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reset-ticks
! [, _) {. j( F1 i2 M. _end
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;; Initialize the global variables to appropriate values, k/ S2 _% V( \! V
to setup-globals: P) E4 I0 w1 r# d6 k
set current-light nobody ;; just for now, since there are no lights yet$ U! ^7 B! W+ o: G
set phase 0
; J( e0 i) w* b4 [9 m Q3 W* l set num-cars-stopped 0
" s5 _: L# B/ b# C- a set grid-x-inc world-width / grid-size-x
1 z$ e: o. t+ Z' q/ o! z4 s% s set grid-y-inc world-height / grid-size-y+ A/ H1 g* ]. m9 ]
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; d% j: K9 x& P2 q! i" Y set acceleration 0.099
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! ~1 [, H( z# `. j4 r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; k9 s, _$ p3 o( B8 ]$ ^0 F0 _% };; and initialize the traffic lights to one setting
- I3 m+ q5 a( x" j$ r Cto setup-patches, n2 P* u1 f! W
;; initialize the patch-owned variables and color the patches to a base-color. [6 `2 O: y$ g4 f7 Z
ask patches. R7 s, p3 M8 `& X8 \
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3 i& V( }/ k8 i set intersection? false' @9 f0 {8 R; w+ _* X8 [- C
set auto? false* T# g9 T; r8 z3 v y
set green-light-up? true4 j0 T% d) ~6 q! i* A
set my-row -1& t2 s2 B$ g$ b6 n5 Q' T* Q
set my-column -1
+ c) x! z+ B" K% D& Z0 @ set my-phase -1
0 s: B4 V! \# u% I" t& \' T x set pcolor brown + 3. ?: c$ a' D" L0 N: }# F# @
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( L) V0 l9 ?& D4 j! P' r9 } ;; initialize the global variables that hold patch agentsets4 k2 [7 c' [6 T+ T# Q, W4 k, N
set roads patches with
1 \0 B! p7 h' a0 w3 _( t0 h* ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" k8 d+ q8 s) e ]' F# s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] e( q2 `% O( Z# {% x4 d) x
set intersections roads with3 X$ d5 ~$ e( s& ^9 b( z# C+ ~4 T/ k8 J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 w( v) ~5 F( n9 k* |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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$ P3 b. a& e& m, R! Q ask roads [ set pcolor white ]
% X/ B0 N5 k1 T% Y: q setup-intersections3 ?/ y6 k, D0 |7 R# K' D) B
end& q s) l$ z2 [4 \) K' H, B
其中定义道路的句子,如下所示,是什么意思啊?3 z; S# [9 C9 Y1 E! w3 @1 B6 [- Z
set roads patches with8 T0 m! J" E: p' _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 P, B* E7 H3 L9 @! h/ R% P0 F2 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; h. ^- u/ a: Q7 x( G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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