|
|
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。7 }8 W! ^6 o4 u# V. R
netlogo自带的social science--traffic grid这一例子当中,
$ l7 }0 S1 h: ^2 c& ]globals9 s4 r4 |# ]" S+ S$ a4 l
[
; b$ i/ C% Z4 H2 L# U& t. D; c1 r grid-x-inc ;; the amount of patches in between two roads in the x direction
& k7 ?4 @5 M5 x1 N grid-y-inc ;; the amount of patches in between two roads in the y direction! c' F4 A R- X+ h
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" A6 ~7 v: Y' |+ L* U ;; it is to accelerate or decelerate
5 b% k! j2 L8 ^" t1 a+ f/ b phase ;; keeps track of the phase$ h N$ @) T% `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ m0 w1 S4 S2 n2 _5 s( d4 k$ p: } current-light ;; the currently selected light. k! O# P \8 e% Q+ F
% C' T3 O w5 A6 o+ y) k! D
;; patch agentsets" R6 U4 x. m6 p$ M
intersections ;; agentset containing the patches that are intersections( ]8 o" g& V: a! z, t6 N. Y
roads ;; agentset containing the patches that are roads
: ~, l" E3 q$ o6 g& t) H% t3 j], ~5 O: O3 o$ r" I
9 i; w. Z, C$ V( gturtles-own
* ]6 f' [! R" ~5 I% B; Q% k[
+ ^, |+ b0 I; y$ n) Y. ~ speed ;; the speed of the turtle6 s1 f8 _6 s$ l' {
up-car? ;; true if the turtle moves downwards and false if it moves to the right* |3 ], X5 l7 `3 F- \( W
wait-time ;; the amount of time since the last time a turtle has moved8 P9 K5 n4 A8 F/ w s- q m& M
]
7 l8 w/ `* p0 P4 t: g" g0 ?0 t& S
" f/ E- W2 e& F) y4 w" ?* ]7 u& Tpatches-own
7 O: s$ e3 B2 c2 \; U[ p' S- _2 E9 |+ c
intersection? ;; true if the patch is at the intersection of two roads- M7 W+ t1 O) Z1 |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 P& W% E8 _6 d+ E ;; false for a non-intersection patches.- x; M- [! \# F$ _' h8 g6 ]
my-row ;; the row of the intersection counting from the upper left corner of the
, n0 M0 {; C1 k ;; world. -1 for non-intersection patches.
5 c$ z8 ~( K( F* B3 t/ y' M1 D# Y my-column ;; the column of the intersection counting from the upper left corner of the
; I5 X: i2 C8 J" T9 d4 a. p ;; world. -1 for non-intersection patches.
2 U& i; D, s( }& t3 {" B: s( w6 q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 N9 Y5 k) T Z auto? ;; whether or not this intersection will switch automatically.
3 K/ W6 e# F! Q5 w2 c$ P ;; false for non-intersection patches.
/ f, ]6 Z5 L. W. y, O2 V% ]]* ^) O1 I$ h1 _7 h
8 R$ E; N b* ?: z3 C0 |) M: n# H& k% m, o
;;;;;;;;;;;;;;;;;;;;;;
: p b. f0 ?/ m8 T. Y;; Setup Procedures ;;2 v/ Z& n1 i' Z& F/ T6 O. t0 g5 @
;;;;;;;;;;;;;;;;;;;;;;
7 D& Y4 ^+ W- ?: E# R
/ q0 Q; R: I# S;; Initialize the display by giving the global and patch variables initial values.* }- p9 j" P! |4 v9 f8 r
;; Create num-cars of turtles if there are enough road patches for one turtle to
, F+ i* X% r, b6 J! Z3 ^* q;; be created per road patch. Set up the plots.
. ~: x! A) \' ?/ xto setup
6 M. q1 v# T; h% C; v ca
( x) _3 d: Q1 X& v) t7 j# v. C setup-globals7 v0 r! a% r7 _# w0 W
) e8 U3 w/ G6 L- Q1 C7 D+ F: j" F
;; First we ask the patches to draw themselves and set up a few variables
1 S0 j$ t/ s! z setup-patches! }0 s2 s& S. ~8 h& ~8 s' D5 r
make-current one-of intersections
+ c7 k& B# s2 z% A) X |7 F- Y label-current# q( h2 |. _- K8 d C1 \# I
) W# p3 ?$ R3 X
set-default-shape turtles "car"
8 Q5 F& w: T* B- }- T% b: p9 y- U, ~+ M8 ?
if (num-cars > count roads)( F; n3 B2 x/ [7 ]: H
[7 h; \( T/ ?/ r
user-message (word "There are too many cars for the amount of "! H2 f, D: i) v; w; ~6 m
"road. Either increase the amount of roads "
) v+ `; @4 d9 o% @1 L1 d+ V' g "by increasing the GRID-SIZE-X or "$ h" j% G0 `/ h* O
"GRID-SIZE-Y sliders, or decrease the "
. y3 @. e6 x X/ Q7 P# S "number of cars by lowering the NUMBER slider.\n"
- J5 d8 z1 k) Q, t6 n: j "The setup has stopped.")
* J2 G; g) L" T stop
2 {& ]* G, J7 q0 z! ]2 ^ ]
0 R7 V- ^# \# z( C% V/ c& h2 Z4 Y1 q
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ L# `3 }9 ^8 Z$ G$ c crt num-cars# u) L( n# s( m6 O. {! e
[" p9 Z1 J! W9 q5 \ Y L
setup-cars
3 H4 z+ g; T( Q& K5 l/ P* V3 E set-car-color
/ z8 V' C6 v% } record-data
; c/ A( P1 |, C ]
) q! _- D1 _8 i$ B6 U# P% Y( }
# n% A& q; i) o1 U3 K2 Z, W6 { ;; give the turtles an initial speed" m# m) ]# @4 `# E$ H/ y2 T# N
ask turtles [ set-car-speed ]
5 h! r# z! J! X3 U
% S; f* s; D2 k reset-ticks2 R9 Z% p5 M( @+ Z* t* V7 o% g# [# F
end
+ L" j" E: F( g+ d/ \/ B1 _8 ~$ w2 Z7 g$ H
;; Initialize the global variables to appropriate values
' S K) s; \& c }2 Y0 }& ito setup-globals4 p$ T1 U( ^1 ]8 y2 w* I, E
set current-light nobody ;; just for now, since there are no lights yet$ u6 Y% X, k0 h$ z4 x& k
set phase 0
( r6 t/ j1 N0 O4 a. Y set num-cars-stopped 0
+ T3 Q) s6 p2 T( B; X set grid-x-inc world-width / grid-size-x
1 N l" R. B' D set grid-y-inc world-height / grid-size-y; a; G1 l) B7 q& J" \
6 p' K& A% I* M ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( H9 s- V/ A' C: h% m set acceleration 0.099
4 G: f. T2 U+ c; A' f# o" G$ i, Y8 vend+ t8 g, H4 H5 N: H
' l3 O! {! X6 l) L, G" D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 w" Y9 {9 z B: w
;; and initialize the traffic lights to one setting
( r/ I, B/ g! `% _to setup-patches8 W4 \1 f/ v9 o" t) y' T1 s
;; initialize the patch-owned variables and color the patches to a base-color
/ f* i3 `7 c! A* Z1 ^ ask patches
& l K2 k" [7 g [
+ ]/ i: e/ _- f. P @ set intersection? false# V: k7 R6 T0 f/ ^
set auto? false
" l* ~2 j8 A+ {: d) |& U set green-light-up? true
* P, p0 ]/ A- t) x) T' a" K set my-row -1( R: H# z: v$ N% O' e+ s/ b
set my-column -1! T: D' M( o6 R& {) m
set my-phase -10 A4 X9 s( `5 h0 g
set pcolor brown + 3
/ Y1 l; J: m. j2 H ]. M) P$ j9 B5 d: K
: a4 J5 @( \0 ~4 G
;; initialize the global variables that hold patch agentsets
6 K) `% c. T1 e- g1 y set roads patches with
, }: `" p/ {; ~( u1 J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 X* h( n6 a6 J/ |8 M) e8 ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)] D4 [/ d; n9 ?4 f
set intersections roads with
f2 C. k9 i$ P" \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 C/ p& U4 J7 V- u4 \# }/ f3 i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 L. X- F: y5 O* `
}7 \7 q+ n& b7 }7 ]
ask roads [ set pcolor white ]
3 b* {$ M8 R3 h" W4 F* e, ^# X+ J setup-intersections. k Y: B. P$ h' L
end
5 q. K# L; C0 N6 X7 P其中定义道路的句子,如下所示,是什么意思啊?
5 f3 h' T- S& j; t set roads patches with
" s: i: f; s5 `7 l* k& q$ h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# Q( [% m" \7 e+ V$ S/ o% N1 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" w5 O2 F w8 ~; W4 q
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? |
|