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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。/ y7 d/ S3 F1 X2 s9 {3 c+ b. J
netlogo自带的social science--traffic grid这一例子当中,
% U0 M2 R. j7 @2 B* \globals, Q3 V: A7 X7 G9 G/ d) `1 j
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grid-x-inc ;; the amount of patches in between two roads in the x direction
4 B6 _" _+ m$ F* r grid-y-inc ;; the amount of patches in between two roads in the y direction1 \, K& K* Y, S2 b8 X" f4 Y/ k7 O
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! j7 a! ?- k5 l8 y6 @6 H ;; it is to accelerate or decelerate
6 u& [* K4 t/ h5 w& d3 d* s1 G9 ^ phase ;; keeps track of the phase
( A7 t3 h# e/ N" k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: Z- ^' k* c4 I. _" K current-light ;; the currently selected light- u& M$ {7 W$ q4 V1 b8 O
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;; patch agentsets
' [$ x1 q% q$ B6 x* n: A intersections ;; agentset containing the patches that are intersections; n6 K4 Y2 s0 G h' Y0 c
roads ;; agentset containing the patches that are roads
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turtles-own2 |, B" g' `( J' R- p
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speed ;; the speed of the turtle( ]( e6 X. P! ] O5 a
up-car? ;; true if the turtle moves downwards and false if it moves to the right
`( a, |! \* D8 }/ n! u0 ~ wait-time ;; the amount of time since the last time a turtle has moved( a% c E0 y3 x# q6 ^0 Z+ p
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, o' L b' F' {1 k8 Opatches-own
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$ |- F5 D0 J0 u1 l, I intersection? ;; true if the patch is at the intersection of two roads
8 G; x1 S1 v7 F green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 n$ i* W t" ]6 Y: V
;; false for a non-intersection patches.
# O3 s) w$ D/ S& ?! c! M my-row ;; the row of the intersection counting from the upper left corner of the
! U7 `3 [9 U( w* u+ z4 i1 W ;; world. -1 for non-intersection patches.
( G3 T& ?$ g' p# a: T: ] my-column ;; the column of the intersection counting from the upper left corner of the
) ?# r6 V2 K$ E% ]* H' y ;; world. -1 for non-intersection patches.: B' l* d N" _$ u* v
my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 X& ~/ P; ~0 c6 Y0 N/ m" c
auto? ;; whether or not this intersection will switch automatically., Q' v9 i$ R+ @+ N
;; false for non-intersection patches.
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9 h& q! a2 Q0 z. _3 ~;;;;;;;;;;;;;;;;;;;;;; r1 @) O& M7 ?5 @2 U
;; Setup Procedures ;;0 L0 R. ^7 T* \2 o. a. D6 [
;;;;;;;;;;;;;;;;;;;;;;
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5 d: Y9 d) X& e$ H- e- [;; Initialize the display by giving the global and patch variables initial values.
3 B3 P+ ~4 D$ R+ R* A) n;; Create num-cars of turtles if there are enough road patches for one turtle to
9 e* \8 A/ ]8 O% \' p1 x;; be created per road patch. Set up the plots.
6 n2 A! g, J" @* U$ Z9 S2 [/ e+ @to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
8 e& Y2 R' d" N( P+ q+ R setup-patches
0 q- s, y& p4 A* r& m2 Q make-current one-of intersections6 o. o9 H& S7 t- q6 O l
label-current1 [) i7 ^1 t- O
: G( h2 a& e& M1 z$ w* j set-default-shape turtles "car"
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if (num-cars > count roads)
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" t9 N% S" H6 B& `4 c% a1 F user-message (word "There are too many cars for the amount of "0 k" I1 q% J" y/ l n
"road. Either increase the amount of roads "0 U* f+ W% ^3 Y8 Z6 ^
"by increasing the GRID-SIZE-X or "% s3 N* g' u1 H1 W- h. R
"GRID-SIZE-Y sliders, or decrease the "- g, M) F2 Z/ h2 p. t; [! Y
"number of cars by lowering the NUMBER slider.\n", G2 @& ^6 u4 q: t$ l/ T6 T4 E$ j
"The setup has stopped.")+ e8 P: \6 c8 {- e$ Z
stop$ m1 X3 f3 F# f! T
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ t0 y/ Q, s. N$ O1 V! \ crt num-cars! l6 O: `% _; y+ U, P D
[
3 D' L o/ A2 `' b setup-cars
4 ^+ ?. s+ v: k* |/ y# ? set-car-color5 K, ]$ }8 j! F1 F
record-data
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;; give the turtles an initial speed
7 W, _$ y+ O) v3 m9 m ask turtles [ set-car-speed ]$ |6 @/ \/ T3 K2 T5 `
/ n6 W& q7 }& s; P# b reset-ticks
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;; Initialize the global variables to appropriate values
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. V8 |7 D n. t+ S set current-light nobody ;; just for now, since there are no lights yet6 E) k9 J! I9 e6 n: u* a8 B& I
set phase 0
" p: A- a- l1 o; G7 K5 n* w( m set num-cars-stopped 0
# x4 e3 [4 Q! m% f) O& a set grid-x-inc world-width / grid-size-x7 |3 s4 m8 a4 _
set grid-y-inc world-height / grid-size-y' Z1 v' E5 y: u, G3 c- J8 w
' K4 p+ r/ `& q7 T- ]; H6 O ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( ?- P( q1 f9 _+ V+ h% u# g
set acceleration 0.099* V r4 x; f3 t; ?+ i9 N
end# `: X6 w. E! O3 I P7 L/ W4 F+ }, m
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 s' P4 u7 e1 x9 x
;; and initialize the traffic lights to one setting
8 Y/ D8 Y7 r4 [. V$ }0 V) p; }3 xto setup-patches
& T% O6 f* C P5 [1 e: m ;; initialize the patch-owned variables and color the patches to a base-color( w6 m2 Y4 t( F( Z; W
ask patches, R: H! w) |' X2 ?
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set intersection? false
7 Z# E+ f! A* d- F1 P4 Z- t set auto? false7 E/ _7 A% a4 K5 b1 `+ u5 M
set green-light-up? true
+ t7 C; ~5 k: v. m set my-row -1
5 V; o" I# F1 R$ S. _& q$ t- @ set my-column -17 Z# V7 q$ P* k/ V) }9 K
set my-phase -1
- ^. c+ p9 D' y set pcolor brown + 3$ Z# |3 |( X: p' q! T" |8 S! y
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;; initialize the global variables that hold patch agentsets5 J! M, F8 j0 |: `$ |" C3 I
set roads patches with7 Y5 ?- ^7 r- J, a6 X4 G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' C$ }) \! E/ Q0 I4 f+ R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; r! ]4 J% W, i$ O7 `
set intersections roads with
$ ^9 m3 T* p+ _ c% f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( @) ]/ x' _: ~" ^: r& m$ B$ D$ S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! D$ n2 U/ \, L: B. |' D
3 q n7 J/ s; @2 K$ G# s ask roads [ set pcolor white ]
/ _" J6 g; W% _6 F0 l& Q$ x setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?2 e* E2 I6 u$ {0 M! W6 R) B. r9 S- L
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: o; H+ k6 ]2 n) s8 H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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