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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。$ j# z( V4 J$ ?5 r* C5 v
netlogo自带的social science--traffic grid这一例子当中,; O2 S( M4 f+ N9 W" N
globals
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/ \0 U& q) _" T grid-x-inc ;; the amount of patches in between two roads in the x direction; k$ g$ Q4 d8 q' ^
grid-y-inc ;; the amount of patches in between two roads in the y direction
; [5 B2 |2 q" W9 B; ^" e: f acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ p6 f8 B/ i$ a2 S" |1 k1 T ;; it is to accelerate or decelerate' ~& x. x' n: s( d R
phase ;; keeps track of the phase
5 ~1 f& k9 q7 M0 Q& d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 r/ b, _+ S- I current-light ;; the currently selected light
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8 D" V# t( a ~ ;; patch agentsets
4 k( v& n- q% @# K8 l8 E intersections ;; agentset containing the patches that are intersections
: W* M" [7 B5 Y" j roads ;; agentset containing the patches that are roads# M* N7 d1 M& A0 }
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turtles-own
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0 Z* l4 d; }3 z( r3 l: E: [" C0 D speed ;; the speed of the turtle
g) y) ]8 c# o/ x up-car? ;; true if the turtle moves downwards and false if it moves to the right
' `# Y+ g6 ~0 s8 e+ l2 i wait-time ;; the amount of time since the last time a turtle has moved
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patches-own3 G" r- z( r2 O3 ~, s7 [, w
[
: w) @7 c" g6 P1 v% M3 o intersection? ;; true if the patch is at the intersection of two roads
; I2 g5 O% q2 [' b7 f' {- c' H green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 V r1 A# x$ g" A; }; k1 P; [6 N* a+ N ;; false for a non-intersection patches.* \2 _5 A8 w6 Y
my-row ;; the row of the intersection counting from the upper left corner of the3 Z) G0 G) {( X& Q# m8 F$ q) e
;; world. -1 for non-intersection patches.# C6 S; M1 f4 x( H
my-column ;; the column of the intersection counting from the upper left corner of the
& M; { _1 z$ L+ T' u ;; world. -1 for non-intersection patches.
/ ^, t. W4 g! v/ E5 d my-phase ;; the phase for the intersection. -1 for non-intersection patches., t5 J/ F% Q+ _6 S; o' ^7 ]0 b
auto? ;; whether or not this intersection will switch automatically.' F8 J! `" b6 R8 R8 V. e. R
;; false for non-intersection patches.# K9 F) H' s! S) D9 A' |# o
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;;;;;;;;;;;;;;;;;;;;;;
4 F8 c+ [- Q& C+ t3 `9 ?' s;; Setup Procedures ;;$ b8 }6 h) v; [/ t- u4 m$ `
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;; Initialize the display by giving the global and patch variables initial values.
! C$ h5 d& a0 ?5 N;; Create num-cars of turtles if there are enough road patches for one turtle to M `5 D! C9 x+ ]; G' z
;; be created per road patch. Set up the plots.
/ Q' W4 M7 d1 @to setup
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setup-globals9 o( W$ y2 P2 v! Z k) X! u
+ c$ V4 Y- Q' M6 u/ h1 f! H8 V s' } ;; First we ask the patches to draw themselves and set up a few variables
1 j7 r, O+ g0 E setup-patches
" I: Q% I! M& s$ Z F% T make-current one-of intersections* S0 _/ d& I8 e* N8 X
label-current
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' z9 U. S: M; O% @* L+ T set-default-shape turtles "car"
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* q ~8 X. M6 q! L+ t if (num-cars > count roads)/ l8 B4 U6 _. W" s1 v' o- ^- D
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user-message (word "There are too many cars for the amount of "
( [) m4 }6 \0 Q1 h' F2 S' E6 ]* I0 }( ^ "road. Either increase the amount of roads "1 S) n1 A ]6 Y( @, ~
"by increasing the GRID-SIZE-X or "$ d+ Q. P' h4 @: [
"GRID-SIZE-Y sliders, or decrease the "
6 |7 ]4 G& {4 [% B% b: Z0 j" J "number of cars by lowering the NUMBER slider.\n"
& w A7 P1 s- r; [; {; y2 ~ "The setup has stopped.")' \$ G& }) Z6 v; [% c! T
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; |+ [& H! h9 V( H* y
crt num-cars
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( t, ]' _, t d, ~4 n, R8 L setup-cars5 Q% `" ]3 J1 n$ D5 k, k+ ^$ o8 L$ P
set-car-color4 ]0 U3 n$ K" m" M* w3 |) n
record-data
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;; give the turtles an initial speed2 C" Y0 D9 X7 p/ f0 t
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values" e# T, f0 j4 p8 e0 e
to setup-globals
) q) p! v$ u6 g set current-light nobody ;; just for now, since there are no lights yet
3 c9 z h" M3 n1 b4 i8 h set phase 0
/ u" ?( Y) V+ L( O) `7 z6 P5 G" | set num-cars-stopped 0, v" T. ^0 t$ c4 W; {
set grid-x-inc world-width / grid-size-x" m8 P4 z% s: Q: F
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& I3 ?+ `- ^4 \7 i/ M3 u
set acceleration 0.099/ p' W8 u, X7 e9 g' z" l7 u
end' U8 ^: Y9 ^+ U5 w/ ^3 f5 [
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 @( G+ p( G- {5 N |$ F;; and initialize the traffic lights to one setting
% l# Q0 O! i8 i3 X' W! c# m) ^9 Cto setup-patches2 l5 }4 l3 G+ S0 U' {3 \% T
;; initialize the patch-owned variables and color the patches to a base-color3 n \) ^, J3 C( S! a- r
ask patches3 f# c9 V3 S, _' F" ?# i% R- ?
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set intersection? false
9 H, [+ H" J, T! H: l* Z set auto? false& x# [8 q5 p6 H9 |& t% Z* N
set green-light-up? true# K: ^5 K, m/ Z/ s9 A @
set my-row -1
5 Q, m7 ]) Y4 d2 _1 V' I6 m set my-column -1
( d1 A- b: P6 m5 S set my-phase -1
`$ Z" R% f+ t% K4 D& L set pcolor brown + 3& a3 p- J* J( T! E- K! z
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8 @% t8 q" l9 y ;; initialize the global variables that hold patch agentsets
/ C. v& k# ], x+ O# f set roads patches with
8 G, X" S/ R$ r" | H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: d+ \$ Y% @' c8 j; X, ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 o6 W t2 B$ R3 J! P
set intersections roads with
4 {( u$ T+ u- M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 }1 d; ~" R+ l" \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 Q9 v7 |% Q6 d2 j4 H, N
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ask roads [ set pcolor white ]
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end4 E, {* D6 \; t1 {/ h7 Q6 e* h& ^
其中定义道路的句子,如下所示,是什么意思啊?: G; c. } t8 Y1 ?
set roads patches with
* o2 O) b& }. \ [2 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- C5 Q) K! e; M8 N4 [! U7 k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* n- [# O! |, O. i/ N/ o! a# F3 o5 K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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