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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。
* G3 @, J: l; L# znetlogo自带的social science--traffic grid这一例子当中,
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grid-x-inc ;; the amount of patches in between two roads in the x direction, a" a9 x$ j3 G
grid-y-inc ;; the amount of patches in between two roads in the y direction
; X, ?5 g( [1 r- c# V2 T acceleration ;; the constant that controls how much a car speeds up or slows down by if% F9 \* d/ L Q' Q' r, B( G5 h
;; it is to accelerate or decelerate
7 t: o# ?# Y; \3 p) p; [ phase ;; keeps track of the phase
4 g: T, J; c/ I3 a% S d; X. K0 s num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 ^! o8 a) q8 l9 @" l
current-light ;; the currently selected light
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;; patch agentsets
3 [. B' T; }/ ^, U- z% C$ V intersections ;; agentset containing the patches that are intersections2 e$ p% S! n- ]/ H
roads ;; agentset containing the patches that are roads# l2 I$ n# @' y7 E0 H
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) ]4 a3 N+ x3 L) L9 k2 nturtles-own. W# O$ J4 }! _1 }
[
5 B6 g. D3 { _7 G; T1 c! @9 { speed ;; the speed of the turtle' I; v- h* ]% A9 X- ^6 _5 s
up-car? ;; true if the turtle moves downwards and false if it moves to the right+ X- V% S7 m6 y8 X) {/ g3 G
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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, C; z2 F" e3 R3 ?. e! B intersection? ;; true if the patch is at the intersection of two roads& s# V! S: ~- N
green-light-up? ;; true if the green light is above the intersection. otherwise, false.! n7 `5 k$ ~* H! [) f0 E% |/ t
;; false for a non-intersection patches.2 G+ d! v8 Q# [' V+ v: s, T) w) Y
my-row ;; the row of the intersection counting from the upper left corner of the; Y9 _0 U9 P# X* i- X
;; world. -1 for non-intersection patches.
) d# j. t+ i l my-column ;; the column of the intersection counting from the upper left corner of the; D( L# N2 w1 ~5 a3 t, s/ C
;; world. -1 for non-intersection patches.4 U$ ^# K. N% [" C
my-phase ;; the phase for the intersection. -1 for non-intersection patches.: j; a, u3 J2 Q4 B
auto? ;; whether or not this intersection will switch automatically.4 u( E4 W8 o* D* b( }
;; false for non-intersection patches.# f( \4 J' Z" e- c, L
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; I& q* m: V9 ]5 W;;;;;;;;;;;;;;;;;;;;;;
2 a8 Z$ j' n6 Q! y% D;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
* z, H9 S' y6 ~" V, W$ T0 w3 b0 A;; Create num-cars of turtles if there are enough road patches for one turtle to
- R7 ?! q& }! v. W;; be created per road patch. Set up the plots.
# j) C$ @& [ K8 |- B9 {to setup- t. k% L' A& t
ca
6 s. W, {; a8 b' I setup-globals
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;; First we ask the patches to draw themselves and set up a few variables$ l5 F; R) V3 @ J! R6 o0 C$ d
setup-patches8 j) j4 R& }' l! w3 ?
make-current one-of intersections
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# @7 |. ?- J; t/ B$ b( H set-default-shape turtles "car"/ D+ g) F# z: u t1 o
' E! Q8 R4 F V( P: _+ d! b if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "; N w0 e P. H ]! w# b) n
"road. Either increase the amount of roads "$ z6 x4 U! Q! [+ Q0 y, P, c0 F$ Y
"by increasing the GRID-SIZE-X or "
; G5 s# `0 N; K" _/ t" b/ ], r "GRID-SIZE-Y sliders, or decrease the "2 s9 i0 `$ T! U: W9 z, Q
"number of cars by lowering the NUMBER slider.\n"
^2 Z$ L, H6 |# f4 s# ~) O "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 E" ~1 Q, i1 F. f/ E/ `
crt num-cars
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1 c. U3 A, J) w+ n& Q setup-cars
+ d" x" ?6 U1 M( L) d7 e set-car-color" c! F1 B. W6 m _' t- a
record-data
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;; give the turtles an initial speed+ @7 ]( \! y, L
ask turtles [ set-car-speed ]
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6 t: d/ i! J X8 R, t! [2 o reset-ticks
b, k9 x4 l+ t& d' ]+ Q! F: Eend
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;; Initialize the global variables to appropriate values
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8 y' V, ~& E4 E* j set current-light nobody ;; just for now, since there are no lights yet
7 M& P7 O p' D# O set phase 0
. l. J9 x& l1 \0 e$ T set num-cars-stopped 0
7 }9 I+ {) z( c! p: H set grid-x-inc world-width / grid-size-x8 `' A9 ?$ v# i* q7 ?
set grid-y-inc world-height / grid-size-y
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, l3 f5 X# o: _, e/ j( b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary+ a, Z0 b: O' ?# B) _
set acceleration 0.099
2 N1 O( u c0 y/ _, ?# v# c aend
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9 s2 G: [8 a O4 E;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 I% W+ x2 q- F7 }8 t1 S: @0 c Z
;; and initialize the traffic lights to one setting
9 ^( p# b" b1 dto setup-patches2 k3 L) ^' H+ H
;; initialize the patch-owned variables and color the patches to a base-color' d. D. H; O" H" d' x+ Z
ask patches# s- c% @+ l2 w7 E% \8 v6 q- {
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set intersection? false8 H) e" @8 A+ x+ J- @! G" t
set auto? false
0 H8 G J' u# q5 M3 m1 _9 |4 g set green-light-up? true2 J; n, v' v( u2 U
set my-row -1
% z+ q7 \% x; ]& X3 `8 b set my-column -1/ I9 q7 f0 y" ^$ K0 T! ?; `8 H$ |0 j
set my-phase -1* U) a: g9 E& \' m( B# Y: H! N
set pcolor brown + 31 F& e6 G, R) X4 r6 k1 a
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;; initialize the global variables that hold patch agentsets, V- G# @ V6 J% [7 D; p/ J$ F D
set roads patches with
# u9 _$ a" W5 T/ { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 N; m) h3 w, W3 f" g$ c. ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 z; K& B6 [$ ]' V" H8 S; X
set intersections roads with1 n Q6 F _) {, ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; H) T+ S: P) |6 c$ P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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( t' T, Q3 f+ H6 G) u+ W- q9 P3 k% B其中定义道路的句子,如下所示,是什么意思啊?6 s. z1 @4 x; E; W) h
set roads patches with
$ z. D, l! J* \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& \9 z" b& _6 }1 v/ z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 o9 x5 P4 p* e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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