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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。& Y' k! L a z J7 W* Z0 {
netlogo自带的social science--traffic grid这一例子当中,9 F$ N" k- H; t$ m: T
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction$ I; O/ u U* i6 ~& L
grid-y-inc ;; the amount of patches in between two roads in the y direction7 }5 a* P. U r' z8 O
acceleration ;; the constant that controls how much a car speeds up or slows down by if- [) y5 a/ g" G! X5 q5 p6 b& R
;; it is to accelerate or decelerate
; u, C; x k2 R$ s' F: u( c% \; f phase ;; keeps track of the phase
* y4 x: v$ g3 E5 s2 ]8 w& t num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
D a! q& S( H4 e1 z current-light ;; the currently selected light: K! R9 L8 {: b2 ?! O( a% m
6 b- c0 K- R7 d" d ;; patch agentsets+ I' e9 m- j1 w# Q2 K
intersections ;; agentset containing the patches that are intersections
" `3 u- p7 E# T roads ;; agentset containing the patches that are roads
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turtles-own2 s' D& T, C) n0 S
[
[* R* i) `2 Z speed ;; the speed of the turtle
* M1 `# M/ F' y- ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right
- a, U: w" L4 y0 A/ q! e wait-time ;; the amount of time since the last time a turtle has moved
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4 @! E4 b6 e7 {$ _) _patches-own
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* m5 N' o! s: ^9 B2 ?7 g intersection? ;; true if the patch is at the intersection of two roads
! r* o7 ^, h; `) s5 |! T1 E$ e0 t1 ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.: [* q* R- P: n/ a! i7 _4 v
;; false for a non-intersection patches.( g$ P3 n6 [/ d S& k
my-row ;; the row of the intersection counting from the upper left corner of the
M0 v+ v2 S J; b4 z( ~/ t ;; world. -1 for non-intersection patches.3 W3 G% J# F$ D" j1 \
my-column ;; the column of the intersection counting from the upper left corner of the' h' Y: u' V8 P7 N" p
;; world. -1 for non-intersection patches.- x7 n1 u5 s; q- Y7 Y$ Y$ R1 F
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' e: T8 `# P; @! s" A! W, r! [ auto? ;; whether or not this intersection will switch automatically.
( S' w. `' ^7 v# R# } ;; false for non-intersection patches./ h6 x0 Z3 v, c5 m6 Q. X
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+ {6 _+ _! d/ l; \9 ]* e8 [$ Q8 g;;;;;;;;;;;;;;;;;;;;;;
2 I, }% Z; g6 W1 H* J3 U, }2 l;; Setup Procedures ;;
/ ~1 m5 G; S4 g- r3 q;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
7 f$ F' \- b- \+ u# v;; Create num-cars of turtles if there are enough road patches for one turtle to
( e: L a' U2 j+ s' t$ m;; be created per road patch. Set up the plots.1 R8 y/ O8 _3 n4 S5 M) I! P
to setup
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setup-globals
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1 |7 @- }, ]! v0 [, _4 ~2 @6 a ;; First we ask the patches to draw themselves and set up a few variables1 w; @+ d. s7 [
setup-patches
: |' \0 ^" Z4 D+ T- G4 E- Q make-current one-of intersections7 I: e1 O) c& C* N6 j
label-current6 y* c2 R2 H* `- B5 i- _
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set-default-shape turtles "car"
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2 x% Q2 B5 ^/ ~# D1 G if (num-cars > count roads)4 M: }# ^7 ]0 M# I6 K3 S
[
' f" t" O4 z5 E! O" Z/ t user-message (word "There are too many cars for the amount of "
* m. W1 T3 n& f$ h; `" C "road. Either increase the amount of roads "
3 D- t8 [' K5 d8 p, g "by increasing the GRID-SIZE-X or "
1 S$ z& `' O$ M( I6 { "GRID-SIZE-Y sliders, or decrease the ", l3 W6 G. F3 [: j# d4 J
"number of cars by lowering the NUMBER slider.\n"
4 q* L5 \3 }4 y, o "The setup has stopped.")
+ R8 S" l8 t: m( U, P3 | stop
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" s4 y3 t" }, u5 N# n) F+ l& k- _ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( l# H+ S* M0 Q crt num-cars
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; \) y1 G, x) b6 {. i& g U8 S setup-cars
5 u; R. D/ r! v2 a" i set-car-color. k2 `; N# R9 L# E7 _6 ?/ L C
record-data3 o9 j& b% B5 N* u; W
]
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; b# F/ a1 C! r9 \8 x ;; give the turtles an initial speed
: j% S" L. s. f* ?# h ask turtles [ set-car-speed ]
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reset-ticks% \3 K- c, e) @+ g/ [9 F0 N
end' R8 R0 p0 Z3 s7 {; g" E6 h% X
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;; Initialize the global variables to appropriate values: W/ i/ }# `" z+ T& e, D. `7 u: P" t
to setup-globals8 k) z4 A; Y9 J) J9 y9 f" e
set current-light nobody ;; just for now, since there are no lights yet& ]7 [9 }* \) a3 c
set phase 06 W7 z8 l. n/ o& G6 `0 ^1 M- X
set num-cars-stopped 0
6 ?' m, m& F, r4 a9 d8 Y set grid-x-inc world-width / grid-size-x
# Z! P( d* k8 Z. p) a: Y 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
6 {+ ?3 u2 M7 F+ P6 r6 W set acceleration 0.0991 @9 i/ P5 J7 `1 |+ h5 p' v; q
end$ o! P& m8 x* _( F: j
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 W) T/ a5 B8 a
;; and initialize the traffic lights to one setting, ]' \1 q& J/ K& \7 C: m
to setup-patches
/ r9 ]8 F7 x' M# s+ R" W; S ;; initialize the patch-owned variables and color the patches to a base-color
- q" @: C* m# A4 {: E+ c ask patches. k/ E" Q' l, L
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( @ Z- l0 g% c7 n- S9 @4 c2 \ set intersection? false
" y. N( F1 r1 ` set auto? false
, K: L' d. Z! } z! q, }1 `, e set green-light-up? true
% |/ b7 J: u- ?9 F K! _ set my-row -1
+ f, Z7 {; A/ M4 P. m( Y: A set my-column -1; ~: b4 m' u& S2 \* }; |
set my-phase -1
( F. U3 z; u9 s& c, o/ _6 o% _3 L set pcolor brown + 3
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- N0 u! _+ p! w4 u ;; initialize the global variables that hold patch agentsets
; X$ ^; b7 T& c3 ^- C6 G- r set roads patches with! D. k/ K$ `" a8 {$ [- N8 S" s2 F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 _/ K1 A3 `# @, n4 d# Q- ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ q3 g! ~; @5 W% n3 M set intersections roads with
; U5 f, F! t6 i3 k1 l Y* ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 `( S$ S9 a/ m& O1 ]" q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ T( w3 Z. G. B1 C* G6 s
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ask roads [ set pcolor white ]
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end
9 E2 G$ K2 N6 @其中定义道路的句子,如下所示,是什么意思啊?9 S: h& y5 B( k" g* `7 W
set roads patches with
/ `- H" q9 v9 a5 E( c7 [: ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. Z; Q* ^3 n2 m7 k+ b) a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 e' L8 ^; l, q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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