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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 W: l6 [3 f9 _8 Q9 u6 {" I
netlogo自带的social science--traffic grid这一例子当中,
9 u9 u6 v( Z+ \# D. [globals. `( e: a- Q+ }$ C! S) e
[
o. f1 U) \/ q9 Q& ] grid-x-inc ;; the amount of patches in between two roads in the x direction M7 L _% w& t7 l& y! `6 N5 I
grid-y-inc ;; the amount of patches in between two roads in the y direction
@& t# D& j8 V acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 b c' W; S h, l" U ;; it is to accelerate or decelerate
. j8 {% i; b8 Z8 ]* c) ? phase ;; keeps track of the phase# L4 P- s* }. W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 i; }+ D8 j- a3 k' l( l% x5 K
current-light ;; the currently selected light$ R3 v) @5 N0 |* G J9 P1 r
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;; patch agentsets4 _ _. L& J" _6 v- n; H X
intersections ;; agentset containing the patches that are intersections
$ M, U {5 z5 Q9 U: I/ b roads ;; agentset containing the patches that are roads
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8 P% y: }8 k7 _# @" Vturtles-own9 I, L5 z3 }- @1 ^
[
/ E# z. N0 Z) I" e( d5 {: V8 B speed ;; the speed of the turtle- I1 j$ _( f/ P' C
up-car? ;; true if the turtle moves downwards and false if it moves to the right
l* s* s( W" A, E" O W4 i wait-time ;; the amount of time since the last time a turtle has moved
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patches-own8 N8 g, s2 ?& n( ]( ?# ?
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intersection? ;; true if the patch is at the intersection of two roads* z# U k% t/ E4 Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.: w, y( e8 t3 n. A* l
;; false for a non-intersection patches.# {4 o- F9 n+ L& e+ t9 W
my-row ;; the row of the intersection counting from the upper left corner of the& F x# B1 d! D' L/ U
;; world. -1 for non-intersection patches.
8 |4 Y6 i5 @2 V' T2 c my-column ;; the column of the intersection counting from the upper left corner of the
: z/ \- q9 s# t, ^! x @4 v ;; world. -1 for non-intersection patches.5 C5 c' y& ~' v- A4 c/ P( g# b* ^
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ N- q5 x4 Z( n' A, z% ^8 l
auto? ;; whether or not this intersection will switch automatically.& \3 v6 X9 j: z+ l* O* p5 g- O) f
;; false for non-intersection patches.
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7 B' _* D$ w2 U, h;;;;;;;;;;;;;;;;;;;;;;
" d) o/ g1 [9 ^$ q;; Setup Procedures ;;& ]% i* P6 O# Q* \
;;;;;;;;;;;;;;;;;;;;;;( G2 c, V% V3 `6 n/ S% s0 `
$ U7 e6 i* L4 h0 N4 F* G: ~;; Initialize the display by giving the global and patch variables initial values.
* ^) {% D9 b4 T$ g) G;; Create num-cars of turtles if there are enough road patches for one turtle to
7 c& {& y! b" B) M9 i8 p! ?;; be created per road patch. Set up the plots.( B! o5 [( b G6 C8 d' o
to setup5 t8 w2 w& W0 c+ w9 I: K
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setup-globals( i. e& q& ?+ q6 [: A( J
+ q; q& T- e% I! ~' l6 y5 r ;; First we ask the patches to draw themselves and set up a few variables
) K5 }. X# R+ R, ~ setup-patches
3 ^5 }2 y7 {" v% c( ?( N make-current one-of intersections6 C6 T, ~* U: }4 F4 K; V% A; D
label-current
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7 p3 E8 y3 a2 _! D8 K3 |2 l; { set-default-shape turtles "car"
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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 "1 O" [6 i4 N. n+ p1 {, |, F; j
"road. Either increase the amount of roads "
! v7 h! I; x0 g: I- W "by increasing the GRID-SIZE-X or "2 C6 b1 O; _2 @6 T" f1 A. h
"GRID-SIZE-Y sliders, or decrease the "
5 W6 w. m7 f& E. ]% _ "number of cars by lowering the NUMBER slider.\n"
; c' ]" b2 ]8 d4 e6 C "The setup has stopped.")$ N, B9 P0 P" _) ?( v/ z
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) I2 K3 I. j: n& E* T5 E1 Y) ? crt num-cars" g6 O |7 F' L' c& B8 @$ X! C U* {
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setup-cars6 A1 e4 z8 O+ X: P6 A$ y: n
set-car-color
( }3 V- {# O$ @/ g8 ~$ y& l* v record-data
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;; give the turtles an initial speed3 T. n3 |6 M" E. \2 i7 x! b. b4 s; k
ask turtles [ set-car-speed ]- ]! B: `% O1 z5 [! K0 b
' Q5 R4 y* V# {" p9 G3 m& ` reset-ticks
2 z, q; ~ ]% Tend
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;; Initialize the global variables to appropriate values; e( ?( d) N# E3 C7 h
to setup-globals
, L; J) p: ^* L$ B) W( l @. @ set current-light nobody ;; just for now, since there are no lights yet; I* n( u: z. b
set phase 0 T$ g) V2 g5 N
set num-cars-stopped 0
( r2 ^6 z* T% N: b7 G2 @! ^ set grid-x-inc world-width / grid-size-x7 a" x% `% ^' P0 X3 ?0 E
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) G+ n6 `; d! a0 x" o% N
set acceleration 0.099$ `! [) K, O9 ~) c" Z1 A
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% B7 d/ y! o$ o0 r6 A
;; and initialize the traffic lights to one setting" b* x. B- W" T
to setup-patches
7 K& W2 b d6 P ;; initialize the patch-owned variables and color the patches to a base-color" B2 I4 Y, g2 ]7 e9 B" E
ask patches5 C9 c' n. o3 g
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set intersection? false
9 x; p3 q9 R3 L. l0 V set auto? false- {+ L: Z- x$ w0 i" t
set green-light-up? true7 E7 V1 Q( ~# P" y$ d
set my-row -1
" Y7 H/ F6 ~% [. L! y u. @ set my-column -1
n0 C7 x) H* O: V set my-phase -11 O. q8 D w5 {3 s
set pcolor brown + 3* s- {( q! D$ t, \
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;; initialize the global variables that hold patch agentsets
* ^: c* n+ ~9 ^: @ set roads patches with, ]! k# O; H3 Z. I: b) k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: N7 m6 {1 C, c3 P8 G( e: o+ K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ `! k" h# j4 q
set intersections roads with
6 i# ~. W6 E2 U+ u& | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( L6 u# U$ m& y2 C9 @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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4 W- b( w8 b9 t( Z% N/ b3 n ask roads [ set pcolor white ] v! g1 x+ M4 Q7 c6 M
setup-intersections$ O9 W$ X, t4 g
end
. x- e. X2 P8 S t$ g7 \0 o% ?其中定义道路的句子,如下所示,是什么意思啊?% v0 M- m3 ^7 n' |' D5 e
set roads patches with
0 V1 \( u x; d! |( G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" L( Q; Z' X5 W# F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 o3 Q+ K- t" R' ~/ O: P4 ~
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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