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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。
6 s/ B7 [% Y+ g$ p" O* H/ _- N! u) mnetlogo自带的social science--traffic grid这一例子当中,% w% }7 w2 `. K9 \- U: t4 G% Z
globals
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0 W7 V/ D, y0 B5 N grid-x-inc ;; the amount of patches in between two roads in the x direction0 |$ _. r/ K6 e! k6 _# u
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 j& q4 ?/ T/ c/ b5 C acceleration ;; the constant that controls how much a car speeds up or slows down by if k: D: L: S0 n; k2 F3 M1 q" k
;; it is to accelerate or decelerate
1 J$ @8 N1 b' w3 f$ N% U5 z phase ;; keeps track of the phase
) b# B; J; W' j% m* c num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. p* d/ f3 }$ R2 G current-light ;; the currently selected light
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: R4 V+ `0 R4 g I& i ;; patch agentsets# Q- x3 V! T1 d) q, U" C4 B
intersections ;; agentset containing the patches that are intersections
6 R" w& o% D) G% P roads ;; agentset containing the patches that are roads
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5 j+ j6 k0 s) B2 Z" Aturtles-own- c1 C' N4 L" Z& m1 }. H
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9 ]; k& r# }% `2 ]+ u& C speed ;; the speed of the turtle, F: d, p- Q/ `6 y; Z0 H
up-car? ;; true if the turtle moves downwards and false if it moves to the right/ S! k. F! }0 D+ k4 u
wait-time ;; the amount of time since the last time a turtle has moved, i. s, @# O" M: k
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3 @; j* j$ k q" Spatches-own
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1 l% ]: v& ?' K intersection? ;; true if the patch is at the intersection of two roads
' ^0 ?9 n5 b# w8 u green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ q- ?6 B& S" ^/ H# y ;; false for a non-intersection patches.
3 `+ y* P' O1 L5 P! }3 ` my-row ;; the row of the intersection counting from the upper left corner of the
) J9 x: C3 |1 l& |4 ] ;; world. -1 for non-intersection patches.! _; m( t% A! @7 g
my-column ;; the column of the intersection counting from the upper left corner of the+ H- n) e h- g& g! W3 ]3 W
;; world. -1 for non-intersection patches.. T- D! c, |/ Y* p. ?2 V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 k8 s5 L; ^9 P' ?% i auto? ;; whether or not this intersection will switch automatically.
1 q1 O1 ?! `! n ;; false for non-intersection patches.
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$ K; W7 H8 s5 {) P. S& E2 W;;;;;;;;;;;;;;;;;;;;;;
: H0 e) {) `0 g- D! J# R/ P;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
6 @6 E0 o- v8 U/ z) l2 |;; Create num-cars of turtles if there are enough road patches for one turtle to0 |- c& @/ E$ l. F* }4 X3 j& p
;; be created per road patch. Set up the plots.
2 a/ L4 `/ j) J9 Nto setup/ p; H3 Q/ V8 s
ca
* X5 w6 c' D7 L, z) t. o/ u+ S setup-globals# C0 ~4 n. m# g/ H8 \
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;; First we ask the patches to draw themselves and set up a few variables( v2 R7 Y F: ^
setup-patches; h3 G, w- N9 i* K
make-current one-of intersections# c' {# ~# [0 _4 ~5 B: ^
label-current
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set-default-shape turtles "car"4 U* [" B- u& s. }9 M$ @ e
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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 "
% f ]4 c6 k3 w, _0 T# c "road. Either increase the amount of roads "
) ?. A/ U" F5 H2 v0 X% D "by increasing the GRID-SIZE-X or "
( ~3 Y/ l. E; P3 G# F "GRID-SIZE-Y sliders, or decrease the "
7 O# }' j& u! m7 O9 Q" o1 C, t "number of cars by lowering the NUMBER slider.\n"9 A, t2 S3 i: P% M- g
"The setup has stopped.")
0 w, s, c7 @) I7 x stop: g! Q. e: m5 b
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, d# E/ D3 B. e3 z8 K) R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color [9 `+ Q' I2 ^- |" @
crt num-cars' E- }' ~8 m2 [" a2 y! O" u
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6 W$ e5 c( j" V5 A( G( X setup-cars- Y; \/ Z1 {! o, D. O
set-car-color! q& W! x8 T; ]* F' }; w4 s
record-data
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) {. z5 B, E) l. w# W5 S ;; give the turtles an initial speed" I. [3 ?1 I A6 u5 g
ask turtles [ set-car-speed ]
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) x4 ?% O+ U) R4 H a- V reset-ticks4 K' O, J* C n# P5 V+ R
end
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
P/ I- {+ k i7 k: ?8 w- ] set phase 0$ @) C _1 f4 n
set num-cars-stopped 0) ~& a# P# J, S; {& [9 B- d
set grid-x-inc world-width / grid-size-x2 u X7 E& v+ f3 o( P; S
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 boundary4 q) c4 q: j; _8 j* C
set acceleration 0.099
- p' \. K! X+ mend
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$ \6 M# k" w: h: m# D( _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( O: l5 L$ e) O8 ]3 b& c/ M6 k;; and initialize the traffic lights to one setting
2 F/ D ?4 _1 d! ^, t/ |to setup-patches2 v- g7 O/ h/ W" \' j& M
;; initialize the patch-owned variables and color the patches to a base-color+ c q/ b2 O) t- [8 @( ~
ask patches$ P ~& |' U) J$ s. c% F
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! {: }2 \$ H7 Q8 E set intersection? false& n% \" S4 K# k
set auto? false
2 k# b j% z& ~& r0 t set green-light-up? true9 X$ K7 W/ E: L2 g W
set my-row -1
; p# O1 Z- }8 h/ T, F7 g: d set my-column -19 H* v0 Q9 d5 H( [' v' q& z
set my-phase -1
5 [3 {% ~# f) ]2 P x; {% m, H set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets: G) l9 ]1 x1 S
set roads patches with
$ B6 x4 L( q7 W0 x4 W# D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* w# [: g- z5 ^% e T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& L2 z# i U1 N: X! F set intersections roads with
+ f$ Q7 x3 l9 g# G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& M8 L" B. s" S" e2 Q( W/ s. _/ P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
1 W# d" K; \. c' f6 U set roads patches with
_1 I0 \: |# C/ q3 C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' \, R, ]0 Q2 i R1 t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 n3 d' F2 {3 e F7 H2 D
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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