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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。2 U9 M- e% h ^" J
netlogo自带的social science--traffic grid这一例子当中,6 u* @% o. `# U. u6 b2 E, p
globals( Q) C7 F' ~4 i9 s3 _
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grid-x-inc ;; the amount of patches in between two roads in the x direction# W$ x0 `. E [' Z0 ]
grid-y-inc ;; the amount of patches in between two roads in the y direction: y1 `0 x/ w9 ~6 v, S
acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ Z% K9 Q# z! @ ;; it is to accelerate or decelerate- z$ x7 j: e* h9 P4 t, [/ N
phase ;; keeps track of the phase
$ W! j# v3 X. C# v/ C% V5 P num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 o, [6 m, ]1 A% e6 }( r% ? current-light ;; the currently selected light
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9 w3 P8 w3 W) ^ ;; patch agentsets
: H- L* {- }- P9 x- Y; t' j intersections ;; agentset containing the patches that are intersections
! a' F# w" f m, K5 e/ H- i roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle2 y- w& p/ J) j3 g, p/ _
up-car? ;; true if the turtle moves downwards and false if it moves to the right/ R0 R' _ s( ^& c
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own8 x( i% `+ Z4 q3 b. ]
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intersection? ;; true if the patch is at the intersection of two roads- M) L3 u& d& K2 W! N3 s A# C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 J- j! s- Q9 {6 l9 L3 U: y
;; false for a non-intersection patches.; ^! |# @/ l" j9 _6 s" D3 d
my-row ;; the row of the intersection counting from the upper left corner of the
2 |# Y! U! S z2 ~; g- E ;; world. -1 for non-intersection patches./ B, r: L+ t& C1 z: ]& c
my-column ;; the column of the intersection counting from the upper left corner of the7 X9 @* S S A' ]4 {% H
;; world. -1 for non-intersection patches.1 c" C/ m* ^9 V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ D- L' R9 t2 o; P% `7 E. C
auto? ;; whether or not this intersection will switch automatically.
, `3 W1 _& v( H5 L N ;; false for non-intersection patches.
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. }7 c% f+ b5 d2 O! K" {;;;;;;;;;;;;;;;;;;;;;;4 x v8 n$ f% K( j# e9 a4 V' S" z
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.) w/ n( o6 g+ [
;; Create num-cars of turtles if there are enough road patches for one turtle to
) X* h$ C+ Y O9 g;; be created per road patch. Set up the plots.0 x, \! C# D% M& W
to setup
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setup-globals
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0 t% A7 ?! \; E; y7 e ;; First we ask the patches to draw themselves and set up a few variables
3 u4 V7 M' Z: a$ K% D setup-patches( v( a+ o+ D% Q; O
make-current one-of intersections- C# d6 M+ j: R& o
label-current9 j0 ~( S ?8 q) \0 t9 v3 z6 O
+ P9 q5 Z* O1 C1 R 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 "( j6 c* X# L7 p8 \' H# z
"road. Either increase the amount of roads "- E9 v% b$ B _* ]3 w
"by increasing the GRID-SIZE-X or "
( G* S8 B& p- I9 e7 f "GRID-SIZE-Y sliders, or decrease the "
! |, c9 ~; N# q "number of cars by lowering the NUMBER slider.\n"
9 e) p- r9 [) C# y7 w- z+ B Q "The setup has stopped.")* V% V! b3 G2 A+ p) p3 w& K% ]
stop
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4 S* H' [6 N* h4 {6 R$ }. J q5 u ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, }' E, y; V$ C/ S, m
crt num-cars) i" l: J& a" q( q* w
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6 E' j! ?# s1 L5 X4 r. _/ b6 f& |6 | setup-cars
- _ v5 f" O" D" L2 ` set-car-color+ C$ B; t# x E; G% j& g+ H
record-data
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;; give the turtles an initial speed( j( K E1 M1 X$ X w0 b- _0 ?
ask turtles [ set-car-speed ]
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( g5 y4 y7 x& n1 V6 | reset-ticks
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% |4 }+ f* q2 ~2 M& E3 n;; Initialize the global variables to appropriate values
( C! k6 g6 X; [, a8 Uto setup-globals, o. `. t* {$ e; x$ \; C
set current-light nobody ;; just for now, since there are no lights yet* \3 F$ x) N6 ~5 v* g1 S) G M
set phase 07 s" I0 o& C- L0 \- t
set num-cars-stopped 0
1 W4 F4 B" ]% f" |4 s. ~' Q set grid-x-inc world-width / grid-size-x: |* S1 O9 c3 e P/ B3 s* Z
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
# f" D$ @" v5 X6 t$ {3 F2 h set acceleration 0.099" c' o9 K: x; G1 @
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets," V2 c& D N! v' p5 y1 |
;; and initialize the traffic lights to one setting& J+ d, M0 I" U0 t
to setup-patches8 D( f; J, t( y
;; initialize the patch-owned variables and color the patches to a base-color
( e+ A6 E3 r; V0 Y u: M0 W" E ask patches
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set intersection? false. Q. @2 S n0 s# {% t7 W
set auto? false
$ u+ A: |5 q) Y6 o2 |; s set green-light-up? true; M$ R% K8 K1 L3 B, r
set my-row -1& O0 O7 _. v! e& F+ T
set my-column -1/ V" e" _" ]# G G D% c
set my-phase -1
+ w# _# ^/ l. R, Q0 Y, B- ] set pcolor brown + 3
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* {) O+ S3 q5 _- A7 Z ;; initialize the global variables that hold patch agentsets
/ N2 A& g8 d. Z' y! f set roads patches with
B! q1 m* Y7 r: k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 z, i r, j, m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ E" H" A! K p. w
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end$ I: o" W3 j: W% w$ z, |
其中定义道路的句子,如下所示,是什么意思啊?
6 @! {2 Z, r: b# m set roads patches with
+ J! l; g1 ~4 m5 F: A' V4 v0 e2 ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 x3 b1 R/ a1 i5 G2 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ ^' N( ~% ^* j, M 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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