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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。# Z4 z8 R! h3 L4 C, Q
netlogo自带的social science--traffic grid这一例子当中,
1 H2 T' y4 M3 j2 iglobals
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" Y, r! I. y# a3 ~4 v9 `( i9 ~ grid-x-inc ;; the amount of patches in between two roads in the x direction! z+ u* ]' I C. _1 r
grid-y-inc ;; the amount of patches in between two roads in the y direction. G3 n0 H7 I' H
acceleration ;; the constant that controls how much a car speeds up or slows down by if- f9 u0 T4 U) d f
;; it is to accelerate or decelerate" N8 G+ B# y+ v
phase ;; keeps track of the phase
4 I8 o. u9 x* _: A! R7 G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 X/ y4 L7 f) q7 S6 t
current-light ;; the currently selected light% j0 j/ u0 L% f
* M( o. u% K. ]/ |* Z& c% K ;; patch agentsets/ a* R- o7 c, `8 o$ L
intersections ;; agentset containing the patches that are intersections: x, [3 u$ N; F
roads ;; agentset containing the patches that are roads& |" \ C2 P7 ~4 B0 J
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turtles-own
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speed ;; the speed of the turtle
( S8 Z, C/ y' I7 ~6 {3 K3 F up-car? ;; true if the turtle moves downwards and false if it moves to the right
" E Y D/ H( E7 {9 F wait-time ;; the amount of time since the last time a turtle has moved% i2 c+ o! t0 g+ y' `) o0 d6 E
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0 W& Z9 }$ j: m3 epatches-own7 e5 a7 _' F! {5 p! O+ c3 Q; o
[
& p" [7 X0 M) }+ g, O2 `& H/ z intersection? ;; true if the patch is at the intersection of two roads
0 N9 {6 u3 r9 X% s+ r# r; t green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 [ f" u6 T& z& j( z ;; false for a non-intersection patches.' ` |. g e: W1 V- y
my-row ;; the row of the intersection counting from the upper left corner of the
* Z) ~ G( H4 Z2 E ;; world. -1 for non-intersection patches.
) K+ H# N! Y4 s$ }# P% } my-column ;; the column of the intersection counting from the upper left corner of the
' [6 z% D: m. L2 _4 z- U+ z) Q ;; world. -1 for non-intersection patches.8 f$ d# F$ R. \: Y3 a
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 ]! n9 N* i p auto? ;; whether or not this intersection will switch automatically.- Q' i; e z- i. X/ n
;; false for non-intersection patches.3 R( S* v" b) ]& i, B9 J
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;;;;;;;;;;;;;;;;;;;;;;- a2 E( d5 a% ~7 R+ w) P
;; Setup Procedures ;;
6 J0 y. ?, ?, i;;;;;;;;;;;;;;;;;;;;;;( q- p- {# a5 U2 F4 f" l/ r
8 j* Q, A1 A8 A4 J;; Initialize the display by giving the global and patch variables initial values.+ g! P" R- y% [ t: Q1 ]; U4 z
;; Create num-cars of turtles if there are enough road patches for one turtle to
. d. n& t9 i/ p3 c( D;; be created per road patch. Set up the plots.6 r$ E$ r6 J# h
to setup
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8 p% A. `4 o# U! ` setup-globals. Z8 [7 U7 G8 e! |" Y
' j: u3 j+ m8 o6 M/ c4 J0 K& I ;; First we ask the patches to draw themselves and set up a few variables
) j+ F& j0 r! t- P4 S% n4 h; D8 K setup-patches
) [: x9 f* Z1 C& n' B make-current one-of intersections$ c X5 W" C5 k# ]! e# B
label-current) T0 N" @- ?! z* l, @8 c( g
% Z1 D, O9 z0 j9 J& o set-default-shape turtles "car"9 r4 h! k* H$ V$ j0 G
: _" s/ j3 t% r& f, }( D; f6 k1 r6 V if (num-cars > count roads)' j( M5 [7 M, O% N) b- V4 m
[
2 o' [, j4 K7 B* H2 |1 t$ W B; B user-message (word "There are too many cars for the amount of "3 I, B( w& ]8 P! N# H: u
"road. Either increase the amount of roads "/ T3 d2 j u& L( p" N
"by increasing the GRID-SIZE-X or "
+ n/ T7 }% c. X$ d "GRID-SIZE-Y sliders, or decrease the "
3 }- T- ^" I! [- ]! k "number of cars by lowering the NUMBER slider.\n"8 y5 J: ?% n2 K( M9 N0 S9 ]3 k
"The setup has stopped.")
+ j0 y* _- w9 ^ stop
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# o9 p* |4 l, ]. j ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" N8 f, y; m$ H0 Q/ o: ^& N& @
crt num-cars
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3 Y4 V5 c- b. b4 c) Y a% g" T setup-cars: }8 C# j8 l/ u: v" B( g2 K8 E! u
set-car-color
# W- b0 j- U3 P" _ ^% D record-data
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;; give the turtles an initial speed
# z) n C/ I! [' E2 l# c" } ask turtles [ set-car-speed ]3 u! o0 S6 j' j9 ]- Q
( O; n3 y7 c9 H# G# D reset-ticks- O/ |2 C/ e, ^& T1 ?% A. {. ]
end
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3 X8 X" e* }6 O$ K4 H0 K;; Initialize the global variables to appropriate values
2 q4 }' F1 m% y8 b. F* H1 Jto setup-globals
! p. s4 c7 o2 |( e+ X' P set current-light nobody ;; just for now, since there are no lights yet Y5 n2 P3 v& s, u9 O2 D
set phase 0
! \9 G2 {4 H0 p6 ^ [5 @: ] set num-cars-stopped 0
" s% a, U# i) L2 T, l/ g1 I0 t set grid-x-inc world-width / grid-size-x2 F% L' r6 V0 D6 y3 F4 ^( x
set grid-y-inc world-height / grid-size-y2 M8 X( x$ d6 p B
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 ~6 p/ `* D6 Q- o; | set acceleration 0.099
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" v5 J7 u+ k. m2 ]/ [% L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 q' d" R3 [$ y6 U2 t;; and initialize the traffic lights to one setting
2 M- t% A. V* N! x: g/ lto setup-patches( z; n2 {- U6 @
;; initialize the patch-owned variables and color the patches to a base-color
- K! N. R& F* L8 k8 t y ask patches
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set intersection? false
3 i2 B1 O9 ~! H& v+ k set auto? false
5 T( ?: ~$ ~* I% l8 W1 N! T set green-light-up? true
9 M$ J: @4 p* G3 O set my-row -16 [6 Z+ H% U3 o# |% R" G
set my-column -1( Q& `, Q4 \" A
set my-phase -1
, _" T1 C; I7 X' W" C1 ^ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets4 i) S1 q0 N9 O, X- \
set roads patches with
# M K0 }; B" q% W7 Q& w( i: J8 P6 q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ R( G ], y4 v' X, C! p1 p0 v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' I; b9 ?' j6 }1 ?+ v( O- o
set intersections roads with5 j, m* s5 I5 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* C6 P6 Y7 T( D( r (floor((pycor + max-pycor) mod grid-y-inc) = 0)] c% B; p2 X( z
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ask roads [ set pcolor white ]- u0 L4 Q& C6 P+ }+ x$ x: n
setup-intersections. i) h! P6 I! Y, I/ }
end; s2 S, j- y7 f9 R Q* f
其中定义道路的句子,如下所示,是什么意思啊?- Y/ l# b# `: l6 H* t- z; l: N
set roads patches with. l% l' T+ U% j B, n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 |4 D: C1 \! l) P# x* r6 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 I5 p! k; ]) A3 J5 o! `$ U$ a
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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