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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 r: g/ p( a
netlogo自带的social science--traffic grid这一例子当中,' ~. T* q" C! G% {
globals+ Q6 z8 y' c% I5 [7 A& L
[
+ m- z8 l# E2 r% b |4 A grid-x-inc ;; the amount of patches in between two roads in the x direction
$ H8 @. Y; D3 }7 ?. ^ grid-y-inc ;; the amount of patches in between two roads in the y direction
5 o/ B, I {+ f% v9 k acceleration ;; the constant that controls how much a car speeds up or slows down by if# C& r! J0 c0 V& V+ k3 [2 N
;; it is to accelerate or decelerate
) U. ~4 V `: ` ?4 M phase ;; keeps track of the phase
) d- q+ B! f/ ` num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. }# j& O- s4 k' \& I6 {
current-light ;; the currently selected light
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;; patch agentsets
6 g, S7 R& v* G3 q2 ? intersections ;; agentset containing the patches that are intersections
' @& e8 }/ p$ \2 R$ _7 Y$ _0 z4 S roads ;; agentset containing the patches that are roads
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8 R. _, G( n0 |, U% Dturtles-own3 r* v# H- I' ?3 \+ J0 A: U
[
: ]* ?8 @" `$ C5 C3 q0 K speed ;; the speed of the turtle
# ~( h& W4 Y- i7 B$ T3 E9 T up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 f1 n7 C/ @9 e* z& T7 | 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
" l) p2 g; l9 y; a green-light-up? ;; true if the green light is above the intersection. otherwise, false. E" x% u. N# A- m
;; false for a non-intersection patches.
F1 z: A; U" Q- } my-row ;; the row of the intersection counting from the upper left corner of the
$ S- _) D5 W( v/ f7 b7 @: u F ;; world. -1 for non-intersection patches./ r1 k: b% _! {' f w
my-column ;; the column of the intersection counting from the upper left corner of the
$ } i. D- v, o2 O. z* [+ p ;; world. -1 for non-intersection patches.
3 l# d9 n* b8 u& i* d3 K1 w1 T my-phase ;; the phase for the intersection. -1 for non-intersection patches.( |: O/ s3 ?: z6 W h! Z7 Y# f
auto? ;; whether or not this intersection will switch automatically.- F3 ~5 U& ]2 |* y. T, _
;; false for non-intersection patches.
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+ T, K) f( r- ]8 T* o5 N& A7 j7 k;;;;;;;;;;;;;;;;;;;;;;2 j5 U) I% o" {6 ~5 k: A
;; Setup Procedures ;;+ k1 `7 y" _4 I. F% n
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.) ^1 R+ D; J$ P& r
;; Create num-cars of turtles if there are enough road patches for one turtle to) s- {$ b/ k y& K/ ?) H
;; be created per road patch. Set up the plots.
" k% u# N- @/ A% P& ?1 Kto setup
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setup-globals, [0 V/ H m1 }0 T
) R9 ?- `2 M/ ^' V* c0 r/ J9 @ ;; First we ask the patches to draw themselves and set up a few variables
0 g: Y1 Q5 w* q; V setup-patches9 t: P$ H0 E! a, ~* L4 e7 ]) R6 y
make-current one-of intersections' U) I8 C. W1 [# Q4 v6 f! `
label-current
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set-default-shape turtles "car": |. ~* y4 b4 ~) w0 H8 F) I$ k
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if (num-cars > count roads)- a* u8 a0 [: J! T2 F7 x3 |
[
' H, S/ G" }& \ user-message (word "There are too many cars for the amount of "0 o" u% ?$ j% P( x
"road. Either increase the amount of roads "- |6 m* t' F2 u; \* ?( J5 m/ s; D. |& b
"by increasing the GRID-SIZE-X or "9 e, |2 ?7 y% ~+ g+ `8 B
"GRID-SIZE-Y sliders, or decrease the "
; x7 e* L: ]1 F8 S/ z "number of cars by lowering the NUMBER slider.\n" J" s+ S J, l4 r. j8 s+ j& R
"The setup has stopped."): f6 L. S* E# s" i" M3 T% j9 f
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, c( o7 z% m0 r) ?
crt num-cars" o7 Z' a$ l$ y# C, I) k' U+ [
[
N4 @6 P% J3 l% H% ]3 F* `( Q setup-cars, ^( j1 g7 h2 n# P9 d$ E# L4 M
set-car-color
/ g c6 l( U. Y. {- ^, m* ^2 \, b record-data5 v0 p- \+ {( g8 w/ @
]& a! c' ~$ |% C6 q" y. \+ S
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;; give the turtles an initial speed; j: l7 w- E _$ a+ j8 U7 p+ k
ask turtles [ set-car-speed ]# Z. |: d+ K: F
1 a4 o3 x- a! l- F2 W5 ^* A, |* _0 x reset-ticks3 m- }# g! u+ c* Q
end6 `4 ^6 _1 q! V6 @6 U9 i( y
/ V3 l' {* _& ];; Initialize the global variables to appropriate values
& x, V5 j: H2 z( nto setup-globals
2 V; ]9 x) \- h4 T set current-light nobody ;; just for now, since there are no lights yet! K5 D5 n: E3 ]' o. N% g$ [
set phase 0
# C9 p5 O8 q' l set num-cars-stopped 0
1 b: r3 |8 s7 ~& R set grid-x-inc world-width / grid-size-x
7 f4 v8 F5 K/ O7 Z3 J7 \2 x set grid-y-inc world-height / grid-size-y4 b ]& m+ |) V+ g/ S# `9 Z
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 |6 `. W* |5 F+ s
set acceleration 0.099% h+ z$ P# c3 }- ~9 K
end' j: x v4 C% ]: v
4 M+ _- k( x1 o2 [( };; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 `. s- |# h7 `' P$ ~$ K. |;; and initialize the traffic lights to one setting; |9 q- j; P) ^3 A
to setup-patches- p5 r+ X% w/ s& M3 p" u/ k
;; initialize the patch-owned variables and color the patches to a base-color* R: M9 B8 N/ }' k% f/ ~+ l- ?
ask patches
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. f2 I$ m# K/ b/ y) }$ b. @ set intersection? false3 |8 i H& {4 w; z8 |
set auto? false1 p2 r% [* w: X1 K3 L# R
set green-light-up? true
9 Q" G7 T7 u, f7 p5 o+ b set my-row -19 N$ O1 w( @* j
set my-column -1! c }: j: n( J! c3 F0 V& s
set my-phase -1
1 M% O1 }3 m- j2 ] s4 U set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
( k# C: t7 n% b6 U! |9 [ set roads patches with9 q$ k$ s1 {4 m8 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* d8 {6 F$ q1 T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 ]. N$ G$ m4 V" X: | set intersections roads with) {1 a" K8 M% r1 \) k' B! n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 }, ~# D7 p5 _/ W$ R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- H2 ]# ]& a8 B: \4 g; W. P0 K
: {8 C+ |0 }4 E: y$ d ask roads [ set pcolor white ]: Y# p3 a# Z5 C( U" Q" v2 F; q
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?
( C/ |. c0 `" Q6 n set roads patches with
# U" v9 S0 m" l1 H" j* [1 R3 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or C: U- b% { U& x2 i; c4 A# H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 Y- V7 j# E5 u: 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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