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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。- j2 E/ U$ u7 ?
netlogo自带的social science--traffic grid这一例子当中,* X) y+ p+ q; R4 s, p! K0 A
globals7 M" B% |- ~0 T- U
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grid-x-inc ;; the amount of patches in between two roads in the x direction
, U2 X) c) X7 g7 G grid-y-inc ;; the amount of patches in between two roads in the y direction
, `% J1 ~* F, ^" b6 b8 Y4 B acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ Q+ v- ~6 d$ c0 K2 N# h" w ;; it is to accelerate or decelerate
$ k3 \9 u5 ~. S" ~8 p# W! L6 n phase ;; keeps track of the phase9 }5 q/ }9 I6 W" k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 ~% t7 D0 |" r8 a( a5 D6 K
current-light ;; the currently selected light
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;; patch agentsets+ w! q: r. F9 |2 v
intersections ;; agentset containing the patches that are intersections4 M- d3 M U' H* q2 y" e$ ^
roads ;; agentset containing the patches that are roads+ n2 I1 L: r [
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turtles-own+ t# Y5 ^* a7 ]: m0 l7 i
[
2 y2 m! M# p, t3 u0 A6 o8 K speed ;; the speed of the turtle2 c" F* s: u3 I
up-car? ;; true if the turtle moves downwards and false if it moves to the right5 w. j* w8 S1 X. U P4 {
wait-time ;; the amount of time since the last time a turtle has moved
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y U8 ]# \' I, s- x4 B) ~ ]patches-own
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intersection? ;; true if the patch is at the intersection of two roads; y4 m8 n' m) `: ]& ^. t$ H* K/ X3 }' V
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
( J4 I: c+ e/ @) Y ;; false for a non-intersection patches.
0 R9 E1 A _- c2 W$ f: N# d# h# E my-row ;; the row of the intersection counting from the upper left corner of the
# U0 r" t# I# C% a& a! Z: F% m5 t- ] ;; world. -1 for non-intersection patches.
+ w# b( t) }8 E6 ^ my-column ;; the column of the intersection counting from the upper left corner of the( v0 k' {8 p$ M" A) b8 J
;; world. -1 for non-intersection patches." E" z* F0 L6 r" U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ }9 {) i- F" X/ Y1 f auto? ;; whether or not this intersection will switch automatically.% Q6 A; ~* W: C$ f( p# y
;; false for non-intersection patches.! X& v1 `3 |* J% s* j
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1 j: T. r% s" }6 k+ Y' X' t5 [;;;;;;;;;;;;;;;;;;;;;;
Q& v, Z: {: W6 v* m;; Setup Procedures ;;/ y8 M' r' Z; x/ s. C$ v
;;;;;;;;;;;;;;;;;;;;;;
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; P$ W; Q7 W) e L# m% F;; Initialize the display by giving the global and patch variables initial values.
0 x) a. C( L7 C) v3 m) j! E. m;; Create num-cars of turtles if there are enough road patches for one turtle to
M- q4 m4 g& }6 @, R;; be created per road patch. Set up the plots.% c* g8 o) _. q$ S$ m
to setup- c- j& F5 D C/ [0 X4 w/ H7 P
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables2 ?6 \5 w) d: h ~: I! |
setup-patches
: K4 I5 |: G% O: T+ p+ ]) w make-current one-of intersections
& U; C8 H0 h% g9 A label-current
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set-default-shape turtles "car"" d5 L' f5 j6 a9 f
# Y' n, R* v, x if (num-cars > count roads)# T+ F# j3 ~ f1 e& b+ m1 Q
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user-message (word "There are too many cars for the amount of ", [% x# K' r8 o0 _+ r* Q
"road. Either increase the amount of roads "
0 G7 C% ~% Y! W& @* V "by increasing the GRID-SIZE-X or "
, t* r$ ?, u- g$ a% s- f "GRID-SIZE-Y sliders, or decrease the "3 [4 C) j: S# {. S4 [
"number of cars by lowering the NUMBER slider.\n"3 D: K' |5 p+ e4 Z4 S3 J
"The setup has stopped.")
, s$ e, M( u4 w7 ^. t B$ ] stop" a5 W% `1 ]5 c! p0 A
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
b' y f; U; P crt num-cars
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8 q; P9 t& F/ ^# p' [$ f* R setup-cars
: s* `7 r/ \; L4 n) t set-car-color
Y" y( _$ s$ w; H7 H z! i record-data% @- E7 [7 M+ T4 y: T
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;; give the turtles an initial speed' w& y, J+ X5 l
ask turtles [ set-car-speed ]
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- @/ g, p$ P: n. S reset-ticks
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9 j* g" [8 T) i6 F; X;; Initialize the global variables to appropriate values1 y6 o, ^( Y2 r% V" j
to setup-globals- U# ~) n6 o9 l
set current-light nobody ;; just for now, since there are no lights yet
- U, j) z8 w( d set phase 0, L! @+ w, X0 d5 G: V
set num-cars-stopped 0
; b$ q3 s- e. s t8 a: ] set grid-x-inc world-width / grid-size-x
3 A3 Q/ r* F* x- e2 E' e" V: D set grid-y-inc world-height / grid-size-y# r8 L2 i5 {8 b7 w0 h
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 {. u2 c" r% y, U set acceleration 0.099$ \3 i# P5 U$ m
end; \; `" k/ ]/ u' J# p
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ ^& G2 ^" y, a. l;; and initialize the traffic lights to one setting8 n) o+ ^3 r3 B/ y/ Y) m. U2 ]3 F3 T1 A
to setup-patches% { T, R" g) Q0 t7 G
;; initialize the patch-owned variables and color the patches to a base-color
% r8 T. z& U: d; I ask patches5 `0 d; |$ M8 J: m9 p# F+ N' h
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set intersection? false1 o9 q; w' O2 o Y" n8 Z
set auto? false% q; I2 b7 r- n
set green-light-up? true
T- N8 O: `9 h j) N( ~7 u* F+ R set my-row -1, s( p2 X" z7 _$ h) w" I
set my-column -1) W9 {4 H4 V% d B; j0 i
set my-phase -1
8 u- s) t1 `5 q& n! }! F set pcolor brown + 3. b/ P/ F: }" {% \9 m& a
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4 s5 Q# s' z* J) V ;; initialize the global variables that hold patch agentsets# M# j6 K; i: E2 F" \$ Q' H
set roads patches with2 K5 o, A, w# c6 q8 v) f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: j6 W+ m% e% l( _. j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 J' `. H' D: |* Y
set intersections roads with
$ V" N0 O+ j7 e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% b9 a+ m% y7 ~. ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end9 h$ f4 Z; m# H% t0 H" Q/ G
其中定义道路的句子,如下所示,是什么意思啊?+ m5 Y& ^, Z4 S: \' T$ W) y( O
set roads patches with% K- z7 p! p2 j, R! v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" i& H3 L& ~1 \8 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. z u1 H4 J8 B V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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