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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。& Z) @8 b* r* D
netlogo自带的social science--traffic grid这一例子当中,# V# Q# s& k# y7 B' l! O
globals! b5 E2 u5 Y$ E- M( I- ?4 g7 ^
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grid-x-inc ;; the amount of patches in between two roads in the x direction# M/ Z3 |8 v4 B1 ]& F) M5 h
grid-y-inc ;; the amount of patches in between two roads in the y direction, p |2 u% l- _1 c) w) T: F
acceleration ;; the constant that controls how much a car speeds up or slows down by if
' B( y' c4 O3 z8 A$ | ;; it is to accelerate or decelerate
4 N$ @3 O0 v# b' w1 ]5 D, p phase ;; keeps track of the phase
- Y# a/ G. ?# v3 Z7 Q4 I' ? num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% K' x" R! J8 z7 H+ H K% }% E current-light ;; the currently selected light7 x* H2 A! k. i( w& a
2 K" q, @. F* @: ?4 g0 O' g ;; patch agentsets
U- D9 l6 M/ i5 y intersections ;; agentset containing the patches that are intersections
- W, \$ M" O! o roads ;; agentset containing the patches that are roads& A( u& l% v' z! c3 b
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turtles-own) f& _% J0 ]5 w
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speed ;; the speed of the turtle
& ? B. }6 J s/ W up-car? ;; true if the turtle moves downwards and false if it moves to the right9 S$ |( U* \) s0 _" } Y7 g
wait-time ;; the amount of time since the last time a turtle has moved% m; Y7 X% ~( X8 b
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads( V6 k1 |( l4 c. i2 a
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 t0 X) q v, X# q ;; false for a non-intersection patches.: Q$ D5 _: W/ ]" t. n7 e+ b) \ z$ J
my-row ;; the row of the intersection counting from the upper left corner of the: t# Q) ?) a% @' |2 Z" K" d
;; world. -1 for non-intersection patches.% z* L; b$ L& H J: D- |# f0 S7 j
my-column ;; the column of the intersection counting from the upper left corner of the
* c0 s* }9 ~" O* k9 ]9 X# a ;; world. -1 for non-intersection patches.
# a+ u0 m: N6 u0 G1 V5 S9 x# z( \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 c+ N( v5 j2 w auto? ;; whether or not this intersection will switch automatically.
8 Z! g5 Q' N- \4 R4 Y, Q$ A2 p ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
6 |" S' D1 G+ u+ k( L;; Setup Procedures ;;$ C2 f8 P- r# ~7 j( S9 R) w
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.& `& E$ ~6 N$ `0 c4 S; ~
;; Create num-cars of turtles if there are enough road patches for one turtle to
: B0 N, _+ {( |: o; o2 o/ y;; be created per road patch. Set up the plots.
. `+ k, i, h" h, Q6 m# Mto setup
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' ^8 Q7 K! i* u9 o setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
$ }5 s. N/ ^+ k4 }% p Q: }+ ]# z: t2 p setup-patches
& A. e) [6 Q7 B- }2 M make-current one-of intersections
$ F; m4 B; X; [4 u0 v/ S' E label-current) Y9 e% h: v* d* ^. l# T
$ R9 e( z% l$ r, F; u; p set-default-shape turtles "car"
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if (num-cars > count roads)
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" D# _) i9 i1 c* x3 ]" E user-message (word "There are too many cars for the amount of "
5 N1 @" ?6 R" M2 v "road. Either increase the amount of roads "
. p" M! i% t3 z2 O1 z7 a "by increasing the GRID-SIZE-X or "3 Z- X2 |. G. ?! \1 M
"GRID-SIZE-Y sliders, or decrease the "
& g! n* w! m' }2 W8 V4 e "number of cars by lowering the NUMBER slider.\n"
1 g& H( \6 t7 U% b; Y6 d "The setup has stopped.")0 r1 w8 v4 m% m
stop3 a" A+ F# J4 c. E8 w
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/ I; ?$ s+ l, c* Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 u0 y2 D! ^, t; A7 R" m4 c crt num-cars
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c4 b3 e( l% c- F8 w1 `& L5 `% _ setup-cars
{0 q" \( [: m set-car-color: i4 |5 h0 e: @( w- D) T' O6 A
record-data0 p, L7 {8 ?) j) S3 n, e) i4 Q
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7 ]* W% ~% r4 T) |% K ;; give the turtles an initial speed
$ v9 H3 n3 Z! W# [% U! L: l ask turtles [ set-car-speed ]+ A5 j t5 P5 Y1 l1 {8 r* K
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reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
! |2 P; N" o! t* ^$ x set phase 0
( B8 V" Q( |: A& E J! L. ~ set num-cars-stopped 0! e( c; r! F3 C1 v9 N$ D
set grid-x-inc world-width / grid-size-x
* G* M8 A# n0 u/ [! v7 {$ g& V( |* h set grid-y-inc world-height / grid-size-y; _$ F" U% c2 v9 [% j" I% x! i% X
& k6 \* o3 N _& ^ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 l7 |2 S2 |- U. r2 Q set acceleration 0.099' J% z: s p+ X6 u8 f- }3 R
end
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5 K, ^+ M- `. t# S3 c2 j5 |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! w0 s. [ d6 d, k g' \1 m, j;; and initialize the traffic lights to one setting& @! W" k8 F- i! g& C! h7 k
to setup-patches: i& s( Z$ \7 Y. F& `
;; initialize the patch-owned variables and color the patches to a base-color. {, W& P" \( Q, X8 i) G
ask patches8 l/ ^, [: |- j; {
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set intersection? false
1 k3 r# C6 z8 x set auto? false6 k; e/ m1 i* b# l5 {
set green-light-up? true
) Q. W+ l# y) R J set my-row -1
' n: y3 V) V8 f3 x- D$ j set my-column -16 U" d: ?) B' ]2 G% T' i% E
set my-phase -1+ e2 t% v! N' e, P* S( r5 y
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
: b: _0 u, k+ A4 a0 o set roads patches with! O! h" J: @! u; z" j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, S- E2 l6 G' u4 l1 t8 Y: Q) y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& l, W# h( H. w% H" }4 Y) u7 i set intersections roads with4 p, U4 G* E3 D: c2 c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ @8 g1 B+ }# Y9 i4 X2 j: S" D4 x9 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 }: {+ c; @3 l1 z
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ask roads [ set pcolor white ]
7 B5 B! X) k: @/ o) y1 t setup-intersections: B8 ^% s1 P1 [9 F! r+ l
end' V# I* ~$ s4 K+ ~ B, p
其中定义道路的句子,如下所示,是什么意思啊?
0 ~! h6 @" N4 F& [& s set roads patches with
+ r @1 O. O5 _* G o1 y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 Y3 l/ k6 P& b; H a3 } W. X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 e* p9 j; e3 _& x0 R4 M$ v2 j) S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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