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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。$ {7 ]: P; d; s
netlogo自带的social science--traffic grid这一例子当中,
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! e1 m1 k( N/ S5 S+ d grid-x-inc ;; the amount of patches in between two roads in the x direction
$ u6 @- M6 M' p5 w& J: I9 _) ? grid-y-inc ;; the amount of patches in between two roads in the y direction
# `' x4 K' l3 q/ R( j7 @) { acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ D4 U3 e8 M, Z$ U# f- }$ _ ;; it is to accelerate or decelerate
# T1 ~) Z" z. ]" L3 @& E phase ;; keeps track of the phase1 B$ V4 t. Y* c$ D7 F, q% E! s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; t1 v) Q. `$ R* T current-light ;; the currently selected light# J6 g/ N9 T% r: U0 N
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;; patch agentsets
( ~8 }0 I6 u3 L" b) B, X! v intersections ;; agentset containing the patches that are intersections
! H+ _7 h# o( f) I+ d, t roads ;; agentset containing the patches that are roads
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- r( g, [2 S; X& Iturtles-own
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speed ;; the speed of the turtle( x4 o7 L0 b/ O4 e" ~) x4 u7 W7 }
up-car? ;; true if the turtle moves downwards and false if it moves to the right
- x5 V$ i7 |9 F, S- p wait-time ;; the amount of time since the last time a turtle has moved
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: D* Z( n9 Y% n# |' B6 ~2 S( l# bpatches-own$ A/ q; Q- P% D% Q9 h9 S8 U
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intersection? ;; true if the patch is at the intersection of two roads
6 [* L- ?! _' y: c y6 { green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! }( [8 X* | x! y$ J: K/ I ;; false for a non-intersection patches.. ~7 h- `! R% s( w
my-row ;; the row of the intersection counting from the upper left corner of the8 }9 X( P# g- N) }& L+ o! U1 V, Q' c
;; world. -1 for non-intersection patches.
0 L4 _* w8 C$ [ E8 ^3 r my-column ;; the column of the intersection counting from the upper left corner of the3 u% R+ D8 `. b. {, D; u( U, k9 A
;; world. -1 for non-intersection patches.* a4 ]. U4 {: e r5 j6 F
my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 z/ U& U. V2 p! F" M+ S
auto? ;; whether or not this intersection will switch automatically.
/ d6 c" k/ o2 l+ }" n4 W o. F4 }) K ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 m5 k/ y8 ?% U;; Setup Procedures ;;7 v8 ?- _1 t1 q9 g, f# L/ O: t
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;; Initialize the display by giving the global and patch variables initial values.
# h4 _+ ~- _, f) o* }6 ];; Create num-cars of turtles if there are enough road patches for one turtle to, w# P' r% E! p4 m: d
;; be created per road patch. Set up the plots.
0 `) G, C0 o* {# zto setup
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: F- ^* ^! x& n: a/ |' I setup-globals
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: _6 J5 V( L# ^& ` ;; First we ask the patches to draw themselves and set up a few variables1 T& r! Z6 [/ p5 {
setup-patches1 v2 m) D: C5 s% C
make-current one-of intersections& }: N& m8 \8 \3 m# W1 H
label-current
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set-default-shape turtles "car"& n% a5 R/ K1 w
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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 "2 b( W7 l7 Q" D* z" Z/ [! K9 L+ c
"road. Either increase the amount of roads "% M8 B. ~+ U) ?+ z
"by increasing the GRID-SIZE-X or "
8 y6 v0 j( }& M7 E" H "GRID-SIZE-Y sliders, or decrease the "
% r# a4 ?# {$ L! U- b "number of cars by lowering the NUMBER slider.\n") P3 A$ s, N9 S/ D, O3 p
"The setup has stopped."); r Z* i6 w9 D7 y
stop; q) F. j8 g7 Q/ c4 N9 w3 x' N1 J
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+ I* y$ _3 v4 d( n2 F ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 k+ s" ]' \) Q* O3 ~- F1 l! O crt num-cars8 {5 ?0 W+ ?7 U9 `' k
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setup-cars
* M! G1 j5 z7 U1 w: p8 ` set-car-color
4 W* ?% U, ]; N record-data1 p: e2 ^$ ~% S) T6 i
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( n, S2 B! q5 B ;; give the turtles an initial speed
: W5 X: ?- ~% H- j ask turtles [ set-car-speed ]1 L8 r" @! g3 W+ ^
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reset-ticks# R1 F2 F2 C+ N/ d) j% K& a
end
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. b' c+ |) g: j4 P7 ^7 v# };; Initialize the global variables to appropriate values4 Q1 h8 V4 ]2 m- H
to setup-globals
7 D( x: R/ F" h/ `+ Q/ H9 L set current-light nobody ;; just for now, since there are no lights yet
2 i/ g' m+ {! u7 F2 g' r set phase 0
+ R* t* B3 E2 R e( t# F! s# D set num-cars-stopped 0
' m) C+ w' E7 @& P% }) } set grid-x-inc world-width / grid-size-x5 H- i4 S. v- J8 L! |2 L, G* V
set grid-y-inc world-height / grid-size-y
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$ }% p: g( I% I4 [4 ?: ^9 C( S ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* {7 @4 t6 l% V* P4 d7 z9 i set acceleration 0.099& l. G! v2 l Y3 C% S. Y! h
end
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* g" ]- { T) M. G1 D; R;; Make the patches have appropriate colors, set up the roads and intersections agentsets, M! R+ D! \6 m& }8 X# _- I0 o2 S
;; and initialize the traffic lights to one setting
1 ~7 h9 s) B+ M6 R* Y# Zto setup-patches+ {6 X9 e- ^4 N/ ~$ Y( W$ a
;; initialize the patch-owned variables and color the patches to a base-color
4 @$ F! S/ y6 v! r; H5 t; m9 s) K ask patches: o5 J9 x- K; s% B0 b' D
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set intersection? false
/ [7 D9 r) {4 R& F$ n# i1 @ set auto? false/ T7 W' V2 _7 C0 b' b+ S: W
set green-light-up? true
2 w/ [; `+ m. x: M set my-row -1
4 l1 f( p7 d. B9 B( ^# Z. y set my-column -1
1 A+ G4 [- k7 Y' e set my-phase -1/ F4 t f+ G) N4 z# z0 I% y
set pcolor brown + 3
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7 H% e7 j& ~ h* i ;; initialize the global variables that hold patch agentsets% {1 z# \7 o7 o- J2 B$ {
set roads patches with5 d' N9 W5 K+ y2 f5 U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' S* Q$ d. ]1 \9 }! d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ G% o5 S6 g) J8 @ set intersections roads with! Y: \# z2 X9 _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 s5 k* }; M0 t6 {) u. u. ^- l' M2 w, K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ s3 V! C$ H1 O ask roads [ set pcolor white ]7 U- {( b" S! J$ ~3 [
setup-intersections
6 w( K" x7 z; V/ Z# qend
- R! @: P* P6 ^* f其中定义道路的句子,如下所示,是什么意思啊?
0 j# E# \) E" t( _: @8 Z set roads patches with
7 T1 {' y& w$ j3 i, c: a' j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 }2 k: ?! f3 Z: }' P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 n* h W6 L( ^% n! y( i
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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