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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。+ B: k/ Y6 `# x" D
netlogo自带的social science--traffic grid这一例子当中,, r: e9 V0 S5 X1 U
globals
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* g+ O) j' A; J3 Z+ D# T+ J0 z8 @* ~ grid-x-inc ;; the amount of patches in between two roads in the x direction4 w/ ^! j; M C2 U. m
grid-y-inc ;; the amount of patches in between two roads in the y direction) u7 D `5 z5 s4 g* P
acceleration ;; the constant that controls how much a car speeds up or slows down by if3 h) P% Z! ~1 [) ^! w
;; it is to accelerate or decelerate
( w+ C4 e! K7 B& v0 R0 ] phase ;; keeps track of the phase
! U/ u u! ]. Y9 x* K; ~' s num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# O( U1 @1 H/ e- @' g1 Z
current-light ;; the currently selected light
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9 J# d0 r# T" m0 k ;; patch agentsets
# \+ k. H; c1 X2 x- F' A2 k intersections ;; agentset containing the patches that are intersections
8 z0 B( n) W1 R: [+ p6 c roads ;; agentset containing the patches that are roads
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# w9 P G) N6 I8 n( w( n4 w. G) xturtles-own
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speed ;; the speed of the turtle( R" y& g3 a6 p$ b( U% l! c2 g
up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ w2 w' C' l% E8 l: t- |/ o wait-time ;; the amount of time since the last time a turtle has moved
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- b" |% g$ Q. q! a+ ^* _patches-own
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% j$ J `0 d$ G" M8 c2 J intersection? ;; true if the patch is at the intersection of two roads6 ~8 L4 e$ Q$ }1 B/ r/ Z- Q5 J' v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& A* N U! B& I9 {5 A! g* S' b1 [3 ]
;; false for a non-intersection patches.
( d8 C. { u4 Y7 b$ t0 y' z my-row ;; the row of the intersection counting from the upper left corner of the
9 M; V# M: A9 D ;; world. -1 for non-intersection patches.
7 I4 n/ E( o$ J- `0 S8 x. e my-column ;; the column of the intersection counting from the upper left corner of the
; ] ?5 ?- L5 @' s ;; world. -1 for non-intersection patches.9 a7 q4 W6 \) v1 j' z+ Z: j; s
my-phase ;; the phase for the intersection. -1 for non-intersection patches., J' e$ R6 z9 [& G3 w
auto? ;; whether or not this intersection will switch automatically.
5 y* Z9 T* `' r" ^: P2 K% X ;; false for non-intersection patches.
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) s& N" A' }2 y( x;;;;;;;;;;;;;;;;;;;;;;
& Q( R- h! L5 ~( C" U! z% u# f;; Setup Procedures ;;5 V* ^2 ?+ w4 @9 O% I b4 _! v9 Z
;;;;;;;;;;;;;;;;;;;;;;9 }2 K# l0 `/ h; [7 f( j8 \
/ i7 _9 d2 x5 s0 e% ~;; Initialize the display by giving the global and patch variables initial values.
# i+ @2 H0 l7 x( @( [5 C& f9 |" b% ];; Create num-cars of turtles if there are enough road patches for one turtle to9 e- y _; p1 I$ R- `0 M) l
;; be created per road patch. Set up the plots.1 |0 W A5 D5 |7 n5 l- G p% Y
to setup: V9 V: d# _2 `+ f/ l+ D
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setup-globals) a2 ^, l9 h" s W/ w1 ?6 k
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;; First we ask the patches to draw themselves and set up a few variables0 u9 z K# ^ |( n5 z
setup-patches
/ |- {( r# S- e- L0 c/ ? make-current one-of intersections! D, m* y. n- Z7 N# G \* F) J
label-current/ _" V0 r; `7 F7 k- F/ m1 q, J- G
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set-default-shape turtles "car"
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if (num-cars > count roads)
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" H0 t! G8 c4 R" {4 ] user-message (word "There are too many cars for the amount of "' [: c$ W5 H ~/ h! |
"road. Either increase the amount of roads ". b3 w& }- M, ]1 ]
"by increasing the GRID-SIZE-X or "1 C& Z; Y; ^, ~2 S9 P3 I. y1 Y
"GRID-SIZE-Y sliders, or decrease the "0 u2 l# m5 E( ?1 L* Z
"number of cars by lowering the NUMBER slider.\n"
5 g" P$ o7 ?+ i "The setup has stopped.")
8 }/ \" |0 \4 w% Q0 i. u stop
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+ M' |( u. a1 ` L$ B$ l; D ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! `. B9 d* p% M9 o, L
crt num-cars
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' i+ R# W g9 r: U setup-cars% Y0 Z& z$ q, a7 `' E) ~
set-car-color0 P* Z0 g' ]- V$ @
record-data0 U g- L, w5 \4 S. }, R3 C, H+ R" b# v8 y
]
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6 t; I* I) V, _) l ;; give the turtles an initial speed) n; ?9 S! C; H8 u2 V9 `4 R) ^
ask turtles [ set-car-speed ]
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: v6 Y$ s$ M$ ?, [& e m2 U reset-ticks2 @: ~% U7 T# k0 I6 e9 ?$ s
end
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;; Initialize the global variables to appropriate values2 g7 ^/ X; k* Y7 V
to setup-globals7 b( v! R" M1 G6 I
set current-light nobody ;; just for now, since there are no lights yet* ~1 V. h* H2 w0 j2 v+ K
set phase 0
* F! c7 f( p5 o+ Z5 I$ @* B" U set num-cars-stopped 0
. Q6 w X: B" O set grid-x-inc world-width / grid-size-x/ O- g3 p8 R0 O% t; {
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
: A* k% O' Y0 |' D set acceleration 0.0993 I) ^/ ?; o5 `0 ?: g
end
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# J+ O e) s/ s) B; y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,; Z5 D) J7 {% N4 B2 |9 Z
;; and initialize the traffic lights to one setting1 C8 m4 Z+ M- X* W1 G
to setup-patches. k3 t/ m8 D: l# b& j- b& A
;; initialize the patch-owned variables and color the patches to a base-color* K$ }+ ~3 Z6 d0 i4 L
ask patches& M; @( W! v7 B% d
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set intersection? false
, O; `. Y; O# N set auto? false; b) S# b' Y8 P1 x* w; {
set green-light-up? true
3 T* U1 J5 u9 Y y0 A set my-row -1
4 s2 }; g( R1 U' X: N% Y set my-column -1
3 d3 S+ g! m6 E set my-phase -17 U0 z p4 @; ^- F; z
set pcolor brown + 3; V7 X: |) u4 Y1 m- C: H
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5 {) Z# j( p0 S; i7 \5 y ;; initialize the global variables that hold patch agentsets
2 l1 \+ }1 _+ q6 ^4 g0 U+ v/ \ set roads patches with
6 @5 \1 U( K8 V0 B3 I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; l9 c" U5 g, ~* ]% ]' \, _0 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; E5 T& d& D3 B% ? set intersections roads with8 |7 ?7 o9 C% l( B9 U, U$ R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 C* S0 y- z g/ c3 ]6 T$ X8 N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 }! Z0 z* e' W2 v' C4 a! y! ]
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ask roads [ set pcolor white ]8 \* o+ s6 W% g. K& v# T
setup-intersections5 F4 j! I( [! Y0 J- o0 G7 f
end
; {& B; u; m, F其中定义道路的句子,如下所示,是什么意思啊?
! P7 P: l8 ], I5 r! [, Q set roads patches with
9 N8 o3 D) P' H" `3 y! ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 G- r( n; H" E) _. t0 ]9 \% E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 A W7 N# Q) \1 }& h7 O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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