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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 |: W0 ~; K7 h3 g
netlogo自带的social science--traffic grid这一例子当中,. l5 h8 J& F, S" C
globals- U5 l2 O4 O: z J0 y3 F9 A1 C/ @
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9 u, A- i+ c# w1 L4 p9 B grid-x-inc ;; the amount of patches in between two roads in the x direction
# s+ y+ t/ ^4 D( c grid-y-inc ;; the amount of patches in between two roads in the y direction
' r& z+ c3 I5 ?4 ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if$ v. |4 f K6 {! Q$ {7 q u9 g
;; it is to accelerate or decelerate* y2 _; O- P8 T# a( _, F. b
phase ;; keeps track of the phase
' h: R% P, w! F, k) j% U0 V: j; f num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ e! @9 S0 j! c1 U5 X6 K4 m* c current-light ;; the currently selected light$ t( q2 t! t4 E. \+ c
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;; patch agentsets
% m5 n6 h5 R1 X; X, S intersections ;; agentset containing the patches that are intersections3 e+ ?0 ^& Q: u2 K$ D. |, x# D
roads ;; agentset containing the patches that are roads, J2 z$ `- ]# F0 [; Q6 u
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6 P- J: D; _* Q9 _: @turtles-own+ J& l' ]$ R7 M/ b q4 K
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. o3 X: ^+ m9 J. w0 x: m6 n) m5 u( f speed ;; the speed of the turtle
" O4 T; T, B2 ]* M+ l: z6 C up-car? ;; true if the turtle moves downwards and false if it moves to the right
( J/ N, m; I' \% ], N1 Z9 u( ]; E6 ~ wait-time ;; the amount of time since the last time a turtle has moved1 K5 E( ^& m% q/ o
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3 I U! p9 u$ I' |) W6 |patches-own V1 H6 h8 w& h- O; F
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intersection? ;; true if the patch is at the intersection of two roads
' o" x9 T, o: E! V i, p: ?! | green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* G4 j9 _, ]# n" p, L2 y1 v$ I$ H ;; false for a non-intersection patches.
% Y9 f. `% D+ h! u H" _4 W5 W( P& ~, q+ _ my-row ;; the row of the intersection counting from the upper left corner of the
0 l) `# H$ l3 ~. O ;; world. -1 for non-intersection patches., \7 f2 W6 a2 N( n
my-column ;; the column of the intersection counting from the upper left corner of the8 W( f$ j4 c; y4 @ ?- m1 Y* n
;; world. -1 for non-intersection patches.
, K6 [; Q; O5 F( g my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 R3 r# V; A' ^+ ~3 }
auto? ;; whether or not this intersection will switch automatically.
2 ]( g* t+ ~" h6 q e8 p0 | ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;) K/ ?, p0 N" ~ h0 _0 i
;; Setup Procedures ;;
7 W) j2 t* k! N;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
- ^. C3 W6 \; ]3 A;; Create num-cars of turtles if there are enough road patches for one turtle to
& S: q& {: ]( P; ?8 G3 t, t;; be created per road patch. Set up the plots.! j8 j. G$ T: J0 H$ B' ?' T
to setup; Y; W! Y% ]; U9 o
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setup-globals, H0 d m# X; D g3 L, F, e
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;; First we ask the patches to draw themselves and set up a few variables) v% n3 T: { O; ]8 I" B
setup-patches" q* k9 X7 r* I- b8 R2 O
make-current one-of intersections
9 j, Y B7 @2 \/ _ |, h7 v label-current" x# C1 l" B' Y" S
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set-default-shape turtles "car"4 ?) u: r, d8 @2 i
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if (num-cars > count roads)$ ]" R' t; s' t! }
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% F: d1 c! a- c% H+ x user-message (word "There are too many cars for the amount of "; V- W" o3 @3 {, s# r/ D) u
"road. Either increase the amount of roads "
, G T6 B" s t1 W# ], {9 F "by increasing the GRID-SIZE-X or "
! d4 @; ~9 d% }2 u, H "GRID-SIZE-Y sliders, or decrease the "
}/ |2 t. A* F) h$ g' D "number of cars by lowering the NUMBER slider.\n"3 c0 @% K2 l. k6 X
"The setup has stopped.")* k0 W, ?5 r6 c4 n" ^& c
stop$ L; S% _4 I" E o
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( l# y5 y" _4 w7 { crt num-cars: Y5 V. }/ k" g' C
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/ m& ~1 Y7 {% y- s: \- z0 E# z setup-cars7 M; e6 r+ V+ y# ], b1 ?
set-car-color0 A; R; |6 `3 n& Q3 G6 i$ }
record-data
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5 {' K% E% o! G- j ;; give the turtles an initial speed$ x" o! i; p! h1 @
ask turtles [ set-car-speed ]6 w. u( D2 u: B
3 j4 H8 P3 e9 g$ c# ~9 \* x0 l& l reset-ticks
& a g( U8 k" U1 t/ _7 nend
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) T$ t# E/ }2 c( D7 k+ A: {;; Initialize the global variables to appropriate values
C$ i/ N% {: P' k* ?! A1 {1 i* [to setup-globals4 I0 b3 g. ^3 D8 ]
set current-light nobody ;; just for now, since there are no lights yet& ^! Y! w$ I9 h2 R: V" I8 p" ^$ f- p
set phase 0
8 p. Q8 T! M( \! Z7 P set num-cars-stopped 0
5 Z) V" r4 F. j& H set grid-x-inc world-width / grid-size-x' Z, y2 }3 _1 W
set grid-y-inc world-height / grid-size-y
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0 b! C5 S9 ~2 Z1 _7 T, H; p% ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# t% u/ z8 z: n5 f ` set acceleration 0.099+ m9 u' b9 f2 B' G6 ~- l
end
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0 A5 T2 a( t5 M* @$ _! a;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# d" o- Z5 ?9 r
;; and initialize the traffic lights to one setting
, G; j/ C- ~, e( @" a% gto setup-patches
: `, X& \7 y; t9 a$ G) l8 |( p, K ;; initialize the patch-owned variables and color the patches to a base-color
( \5 ^3 `5 j3 {% ?* c* i) D ask patches" }" \, G+ n* o, I1 c
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set intersection? false" ]' \" { |# ^/ h1 P5 S* [9 {! c
set auto? false* G( I" `( |7 F l J" c
set green-light-up? true
+ ~# f; j1 K2 e- I set my-row -1% o+ P: M/ D4 r4 K$ Y
set my-column -1
9 a+ m9 c2 k; N( K7 s/ u0 o# B+ D set my-phase -1
5 E1 l. ?' H: c& J8 \) o: T set pcolor brown + 3
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& a0 [& G7 ?) e% n, Y) l/ g3 O: Q ;; initialize the global variables that hold patch agentsets: A1 \! B% ^5 \4 m+ S
set roads patches with; k( V, l0 `' N4 i8 V$ W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 M3 o0 i% O7 o L d# s$ l; y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], ^3 E7 w% z9 ^# z! p3 ^
set intersections roads with% q0 s9 {2 O7 N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 d2 L4 n h: U2 w& i" G% b2 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" o0 j& U4 |1 {& w8 i
7 o, [' [7 ^8 _3 W5 ~" l {3 K ask roads [ set pcolor white ]
, N. K/ F1 e1 g: n9 O# `8 O setup-intersections
$ B5 K, z9 E- G* oend
2 \) e# z9 ^ N% a, K* ]其中定义道路的句子,如下所示,是什么意思啊?
& l) e% j$ @2 _' b# p+ G set roads patches with
' v6 S2 w! E# M1 _# K6 Y+ U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 \) y. T- G0 r6 d' H ^) U+ j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# K( }+ a+ ~2 u- q) M9 y
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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