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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 w/ U) p8 H' F5 C0 Znetlogo自带的social science--traffic grid这一例子当中,
7 {5 ^: o" t( M, c2 l4 B8 D( Bglobals( t% ?, ~# ?( H+ z0 w% ~8 L
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) z y' w- a2 g9 r3 z grid-x-inc ;; the amount of patches in between two roads in the x direction
$ y4 k/ O6 a2 X: @" d2 b) N grid-y-inc ;; the amount of patches in between two roads in the y direction. }* m- v1 y7 [3 C7 @5 @; E
acceleration ;; the constant that controls how much a car speeds up or slows down by if
: v( K9 e* L; z$ ?; p ;; it is to accelerate or decelerate8 ] P: M/ H2 R8 K4 F! x, ?
phase ;; keeps track of the phase) G5 {% R6 \- d3 \( M/ N# r
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' ]* y% d$ w% y
current-light ;; the currently selected light
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;; patch agentsets
' h0 f& {! B& ` intersections ;; agentset containing the patches that are intersections8 C, l2 Q, P4 O
roads ;; agentset containing the patches that are roads
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) a! a }6 Y* m+ [; f m9 q) m: e. qturtles-own
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$ N" a" F* W% q* K- h3 ?# A0 t7 d speed ;; the speed of the turtle, A2 @5 |) t2 n: a% Y
up-car? ;; true if the turtle moves downwards and false if it moves to the right" i+ D5 m$ P% {1 G" p/ v
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 roads8 T X3 ~, S/ {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) K8 k2 J9 V' r: j3 x( z ;; false for a non-intersection patches.
4 I; a4 j1 Q# b) V8 B my-row ;; the row of the intersection counting from the upper left corner of the
0 D: V E7 i& J# b ;; world. -1 for non-intersection patches.
7 H( {( a/ t3 G2 x my-column ;; the column of the intersection counting from the upper left corner of the
' M @2 H6 s; z* G ;; world. -1 for non-intersection patches.
4 s! @. E; _$ k+ J+ R my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! N* X! H+ C5 l, w auto? ;; whether or not this intersection will switch automatically.
* x2 n- N/ c9 l1 g/ Y* l$ i5 ~ ;; false for non-intersection patches.& M* t5 n7 e3 Q
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! ^; V) U* k3 S* d4 v6 E;;;;;;;;;;;;;;;;;;;;;;
9 G/ A( n* P0 F6 w( Y3 y* q$ x;; Setup Procedures ;;( z O& o7 |4 }5 J3 {
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;; Initialize the display by giving the global and patch variables initial values.
0 c" @3 G* Y: L* Z6 P;; Create num-cars of turtles if there are enough road patches for one turtle to
0 c+ Y- A! T( _2 g/ ?6 K% y;; be created per road patch. Set up the plots.: I, Y8 x+ M" N4 ^' r
to setup
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setup-globals
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% x8 S# O3 s/ N$ c5 N } ;; First we ask the patches to draw themselves and set up a few variables
; x5 E* j; Y# |- n, |5 c* j setup-patches
# X* P X: {% H2 e make-current one-of intersections1 K2 J' O; n6 Q
label-current
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set-default-shape turtles "car". t& @$ I- \5 I/ e$ H" v
5 r! A, j5 p- s, [$ [. m if (num-cars > count roads)* f* b$ c: f6 T( i
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" z) r& {9 D$ b, f0 n! i4 ^, z3 h# ` user-message (word "There are too many cars for the amount of "
1 A1 x4 w, k! @3 b "road. Either increase the amount of roads "* k8 u' c% e, Q. x4 _% l' P9 e# l
"by increasing the GRID-SIZE-X or "
8 i0 p) K/ P) K/ P7 o9 N- S4 m "GRID-SIZE-Y sliders, or decrease the "3 w0 i' @& y3 ?$ G9 X4 G
"number of cars by lowering the NUMBER slider.\n"
8 e) f% S9 N# o8 z& C "The setup has stopped.")- |, z7 X+ E, z& i3 s- W5 |
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 I& Y4 k2 s/ w1 X4 ?/ V9 X crt num-cars- z3 [, [) u( D
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setup-cars8 E4 ?$ r- C* W& y- K8 X' i
set-car-color9 E+ B; O- U" `7 j/ V5 C# c
record-data
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;; give the turtles an initial speed% o0 z! B( x/ B7 A& W4 a
ask turtles [ set-car-speed ]3 e. I8 O4 K6 y
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reset-ticks6 ^& X. _9 v) B* y8 T& b; n( F7 J
end
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;; Initialize the global variables to appropriate values0 P- R# a7 k2 g, n+ V1 n
to setup-globals% b9 o" k7 |3 W, }7 q3 D) J- k
set current-light nobody ;; just for now, since there are no lights yet
5 K" \+ [: h' M9 u) B8 k set phase 0
& f3 h3 _$ b' I( z5 D set num-cars-stopped 01 P& f6 v- a; @' E. G& _3 J
set grid-x-inc world-width / grid-size-x
% F; h2 `$ a( ?- H set grid-y-inc world-height / grid-size-y* {0 X" s& ?+ }& |% G8 M$ N- J
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ Z4 Y& i; E, A, ]6 [" L6 M
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 b8 k- x+ }% [2 C" ^4 N
;; and initialize the traffic lights to one setting
L2 E4 n) \ N( [* w, Rto setup-patches
5 W% F5 G! ^8 B4 q ;; initialize the patch-owned variables and color the patches to a base-color
H/ H0 `5 k9 p: Y ask patches
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7 A+ T6 M. w6 X& i$ ^ set intersection? false
+ e. U% J9 D, g6 ~$ ] set auto? false
' w2 h3 V8 \9 Q3 L/ ^5 Y9 T7 v, V" L set green-light-up? true. X7 o2 a# t6 c% R7 R* u) [1 b
set my-row -1
9 `& y( ]2 K; ?; M: Y, {1 L9 m- ~' \ set my-column -11 C _- w- Y6 j6 e. t7 F
set my-phase -1
1 ]7 e: T4 _5 o5 }8 e, t$ L$ I set pcolor brown + 3" M% U/ _$ m) [) H! A
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# D# e' v( N+ p+ K/ T$ q ;; initialize the global variables that hold patch agentsets
, D7 w7 Y( I( Z5 Q/ s% q set roads patches with8 d$ }" _ _0 g @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' z# c3 R& \8 _1 P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
?% s% ~7 z- O/ j4 n2 {9 D3 B set intersections roads with
* T: G; @4 t& K, I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 g' Y8 N: ?! e9 Q- E+ m5 Y" t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] b; u2 {3 x# v+ W$ m6 g
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ask roads [ set pcolor white ]8 c4 K7 }0 V6 m
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?
" N2 m& u* G) v% i+ M) u2 G set roads patches with7 l; O& ^3 l1 }8 d3 |* F$ e2 D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 r6 ]! g, p/ T9 S) q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 w- L: s R4 R J. c* @! |5 {9 N1 v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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