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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。" K, V8 [- f9 }; V/ N) M! h" [/ S
netlogo自带的social science--traffic grid这一例子当中, g. _7 M( p6 F3 k9 F
globals3 D1 F* M% g3 k1 J
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grid-x-inc ;; the amount of patches in between two roads in the x direction- }5 Y( C% M! M F& U
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 p4 Y f1 I9 X, N acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ |; b0 q; p/ j2 o4 ]* e, j ;; it is to accelerate or decelerate# H/ ?% u* C/ d; I- E% `0 R
phase ;; keeps track of the phase
) @% W2 A3 ^# E4 z- ?, u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 r+ m/ x0 H2 {" ^9 X( ^" B: ^" r
current-light ;; the currently selected light
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;; patch agentsets) t# D3 k7 w# g/ g% x+ s
intersections ;; agentset containing the patches that are intersections
5 A+ [: g9 p6 F* L' N roads ;; agentset containing the patches that are roads$ j; N: u7 M. O/ g3 o% b
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8 e! j# F8 u$ N- Y) mturtles-own
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speed ;; the speed of the turtle
" z+ K0 ~+ D1 K# K9 P4 T: G" j up-car? ;; true if the turtle moves downwards and false if it moves to the right1 r0 I$ |+ V+ _
wait-time ;; the amount of time since the last time a turtle has moved1 z. P' N. M" N, y9 ^- l
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patches-own5 M8 u- A$ b4 A$ d
[
K4 ]% O5 O* J# E6 V intersection? ;; true if the patch is at the intersection of two roads2 m" o8 ?8 R: ~7 z2 H0 x% m
green-light-up? ;; true if the green light is above the intersection. otherwise, false.; e9 z: A# g3 Z$ K' E
;; false for a non-intersection patches.
5 r* p/ ?, }5 X5 \" | my-row ;; the row of the intersection counting from the upper left corner of the8 u# |3 y. O1 \$ ~8 N0 Q
;; world. -1 for non-intersection patches.4 z9 U1 f+ x6 u, i0 I
my-column ;; the column of the intersection counting from the upper left corner of the8 X6 b2 z+ x" f0 q. s$ ~9 ]: G
;; world. -1 for non-intersection patches.
4 ^8 c% ^. ]4 Z+ q my-phase ;; the phase for the intersection. -1 for non-intersection patches.- L. k* L2 z, o( Y# b9 l8 i
auto? ;; whether or not this intersection will switch automatically.
* G/ ?6 z2 U X+ L' ^0 ]$ [ ;; false for non-intersection patches." X5 \! s7 x( ~- S
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;;;;;;;;;;;;;;;;;;;;;;
% P5 n% Q$ _ `: Z$ H;; Setup Procedures ;;
0 D D9 f4 i* n3 V;;;;;;;;;;;;;;;;;;;;;;1 _3 H2 u1 s7 X; Y' t9 g2 A
3 I+ e4 O% e1 L& f/ W3 d R;; Initialize the display by giving the global and patch variables initial values.
. I; G0 v8 D# P n+ z9 \0 W. x;; Create num-cars of turtles if there are enough road patches for one turtle to+ V* j& u6 K m2 l
;; be created per road patch. Set up the plots.
; ~& N7 S* c% S: r. dto setup, R9 n! b: q" e, |: K0 h
ca
! M; @+ C- e { setup-globals6 [0 d9 q$ ^( j( @, j1 F8 J6 W6 W
% G; V( k9 Q# R% a6 I/ ? ;; First we ask the patches to draw themselves and set up a few variables ]# \' y: B k& }& ^5 W" r! m
setup-patches
3 W3 B1 h, x% d9 k8 g* N- N make-current one-of intersections1 W% ] k' a* \
label-current
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( {2 a" P' I3 ?7 T) v6 N4 } set-default-shape turtles "car"5 l$ ^% `! G: ^! K- a# f) Q3 C% w
2 V& H! N8 r, X5 C: I if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
/ J2 J4 t/ k8 a- B- }% O2 U5 j "road. Either increase the amount of roads "! f9 A7 w9 W" N6 i
"by increasing the GRID-SIZE-X or "! g$ [; ]. W- d1 v# Q4 u% t
"GRID-SIZE-Y sliders, or decrease the "6 V6 w+ ~2 i: K* W- k" V& A3 a& G
"number of cars by lowering the NUMBER slider.\n"
6 w" s" {! t" @; { "The setup has stopped.")
7 Z3 G4 Y O+ Z- y! \$ N& o stop
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: S3 w3 }. E! [$ R4 j& B. C! k ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& }# `* J q0 Z
crt num-cars
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& D) A. m0 y+ x! P setup-cars+ B% a+ ?5 [6 h% f+ l
set-car-color# n, v8 P5 v" Z% r8 h
record-data% ]$ k9 g) U$ s6 Z0 f, ?
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1 r' R# j, v0 n9 x ? ;; give the turtles an initial speed
0 f, L: j; U# X ask turtles [ set-car-speed ]: {* y* _" L8 M$ W7 T* |
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reset-ticks
9 L( ~/ [" O- y% \; o" m- @end
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. G8 L' g3 Q2 ?;; Initialize the global variables to appropriate values
$ m# J' Q F* B1 j0 x1 ^$ wto setup-globals9 R o$ A. `! s0 d. n3 ?! B. ^
set current-light nobody ;; just for now, since there are no lights yet
/ j& R$ R- H$ G) [, q' u set phase 0
O4 E, M% Z: T+ n$ ? set num-cars-stopped 0
: L, @1 N) W0 V5 y: x0 H set grid-x-inc world-width / grid-size-x
3 X9 S7 s! k8 i1 P" A' b set grid-y-inc world-height / grid-size-y. e* H) w- p n$ T; x; C: P% V. |
( G& m. G" v3 W/ n6 t ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 n/ V3 ?* F) H: _2 @! J9 H5 T set acceleration 0.099/ Y$ n/ N9 K8 ~1 F! L5 ~3 z8 y
end, S2 b& a# Q2 D/ O& A' M+ R. q# r
6 j( v" t3 O) O8 N) u' ~% w0 F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- \* S! w3 ^1 k& L$ w ^4 I& @0 q
;; and initialize the traffic lights to one setting
4 _3 K0 v7 U- d: ?2 f: U c) Bto setup-patches, T6 c- f4 F/ |# u9 \! J
;; initialize the patch-owned variables and color the patches to a base-color! C( X3 ~+ D* I( ]$ Q( ~" u2 \0 j" E" Q
ask patches
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set intersection? false; J& N- [* @! d" Y2 D
set auto? false" W1 U' z) B' u( @
set green-light-up? true
1 Z( c' A, s" T" L set my-row -1
1 A" H7 O$ V* y set my-column -1
/ {4 W; J( b# ^ m7 l; S! a set my-phase -1
3 v S5 e0 L4 H set pcolor brown + 3. Q4 P) V, G8 ]! U8 g7 Y7 o: d9 E
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;; initialize the global variables that hold patch agentsets
" B+ B- o9 F" p' ~7 X set roads patches with
/ V! ]/ D* z/ g0 x7 ^1 J e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 ?3 {" @" o" ~ G6 K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 t5 n! T6 ^4 }: L6 A set intersections roads with
9 o0 M2 y* x0 g3 r0 c9 |' g, l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# ~* u! X0 q& r! h# K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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1 `' Q; w' i* D9 s. p: Q" x% ] ask roads [ set pcolor white ]5 h1 Y$ }, @0 _. Y- F# a
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?
, J6 Z" G4 T3 F3 g/ Y/ j# b9 L set roads patches with
( v3 l! }# X, o5 _: r0 @$ p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( g6 `7 B J4 B7 t, S/ t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 u( W( Z# G$ B2 ^
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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