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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。
. C6 c/ C4 V# _1 `4 E* A( ?# mnetlogo自带的social science--traffic grid这一例子当中,
9 e2 o7 X) d0 L" H2 dglobals$ c/ U+ u9 v; W6 g
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grid-x-inc ;; the amount of patches in between two roads in the x direction! [# P; Y! j# I' V8 q4 S7 X' t: a
grid-y-inc ;; the amount of patches in between two roads in the y direction
, a( o& M" r5 g, A/ a& Z acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 Y' b0 j& w% p! P: [4 W: G ;; it is to accelerate or decelerate
% q! a% C1 B: G' Q9 \9 ? phase ;; keeps track of the phase0 d0 j( Z7 n8 [6 F% G) H% j; Q, U
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" X! v$ C4 H$ B, m% }7 Z
current-light ;; the currently selected light
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;; patch agentsets
: A2 U4 Y% D% a4 Y intersections ;; agentset containing the patches that are intersections Q, S( T k9 D
roads ;; agentset containing the patches that are roads
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! Q( V0 d6 ^" i5 i) I# W+ B1 Sturtles-own
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9 K9 D4 y$ ?3 s) k2 H( c Z9 N speed ;; the speed of the turtle
+ i0 e8 s8 ]3 k up-car? ;; true if the turtle moves downwards and false if it moves to the right4 e! C8 U; b9 e, e g* ~( K* ]
wait-time ;; the amount of time since the last time a turtle has moved6 e* G( p9 S6 w( d
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patches-own: B2 L! j$ s; S% J! h. p% r
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intersection? ;; true if the patch is at the intersection of two roads
' B9 T3 ~! d9 G+ m8 \ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! X% s% h$ w9 v3 g1 c4 \ ;; false for a non-intersection patches.$ ]4 ~% c+ s0 { E8 ?8 C
my-row ;; the row of the intersection counting from the upper left corner of the( {' ?. N% y9 o% w$ {# O' c7 W
;; world. -1 for non-intersection patches.
5 w% p! `) ?# a3 A my-column ;; the column of the intersection counting from the upper left corner of the* i1 h, R0 X W8 t0 @& V
;; world. -1 for non-intersection patches.2 X f5 }4 @1 O6 r
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 b1 M2 O3 q; u6 t) g( z/ r auto? ;; whether or not this intersection will switch automatically.
- i v4 ]; b2 K# A7 W# V3 K ;; false for non-intersection patches., W' t7 h9 m' Q) p+ J6 u( N
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; M3 i- {, D- T;;;;;;;;;;;;;;;;;;;;;;
( h* ?( M4 X" w' i/ m. `2 \6 Q% \;; Setup Procedures ;;
3 B# ?' Q- K8 u: M5 r;;;;;;;;;;;;;;;;;;;;;;. o! r! ]+ G- K
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;; Initialize the display by giving the global and patch variables initial values.( X, h; s7 ?; N6 p4 S" a
;; Create num-cars of turtles if there are enough road patches for one turtle to
1 T# j# |: D0 g1 |( q& ]& ~$ x;; be created per road patch. Set up the plots.
. \$ U3 q8 x, Ito setup! z( e8 i4 F5 Z1 n% I* H# O/ k
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/ f% w; S* n4 e6 E: |0 [- G setup-globals2 {3 f6 H2 s& d
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;; First we ask the patches to draw themselves and set up a few variables6 T0 U" w# T) z0 S: d8 i3 z
setup-patches
! O; b- K) Y0 ]' Y! L make-current one-of intersections+ R3 s3 }* W# L5 o9 F
label-current
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+ {/ p9 h/ Z: W) V1 z, l set-default-shape turtles "car"
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if (num-cars > count roads)
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9 C7 x3 P) b9 ]- S ?8 n- P user-message (word "There are too many cars for the amount of "2 j* C- Q% m5 M- J U
"road. Either increase the amount of roads "
9 `# O! `5 G4 K "by increasing the GRID-SIZE-X or "
% C# g' O) x2 [ F% D2 g3 C) I "GRID-SIZE-Y sliders, or decrease the "
, B2 G. Y' G# x "number of cars by lowering the NUMBER slider.\n"# K% ?/ }1 \6 [2 r3 x
"The setup has stopped.")
# D/ v/ m% F, G4 V stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( h4 J. _, o2 F crt num-cars$ B6 t+ V8 V8 E. Z* z
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setup-cars* X" `7 ^7 D* o5 {# r! H) R+ Y
set-car-color
, a. R2 s; G- x: d5 J* l record-data
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;; give the turtles an initial speed
% v. J, @4 _# D: @! w: [1 g& H' m ask turtles [ set-car-speed ]
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reset-ticks1 S$ p" k# A! Y$ x. t t1 F; d: v
end7 R) _( h; d: z1 P5 u
2 G0 ?+ {( N# t% J- t8 k% j;; Initialize the global variables to appropriate values
" T; F+ A) \% V: }to setup-globals
+ G+ a6 }' E5 y: w% W* {+ s set current-light nobody ;; just for now, since there are no lights yet6 ~, r8 T8 K6 E, n
set phase 0
_1 \0 G9 H6 _# p \ set num-cars-stopped 0$ c" L2 M% ?% u' b: V0 u5 v
set grid-x-inc world-width / grid-size-x
1 W' Z/ L3 S) v O 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 boundary9 }6 t9 o" s# c# l5 T
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
' u6 I( t2 H0 y9 m+ q/ [% L5 d0 i( g;; and initialize the traffic lights to one setting
* u; F9 i2 b( w1 J- z' ~3 W# T! }+ ~+ mto setup-patches
& _0 _) R3 {2 q ;; initialize the patch-owned variables and color the patches to a base-color, a c- B2 m$ _3 Z" L: ^, q- d/ M( V
ask patches7 M/ b) _3 Z4 ]6 ~% x. ~, ~
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2 Y- c* x" S* R" t D6 ^ set intersection? false8 k2 i' b$ z4 l- ^2 }
set auto? false3 M3 W# G: }+ U- M
set green-light-up? true2 k2 g& o3 v0 W8 b' i
set my-row -1( w0 B* P n$ m5 }$ d+ n0 G
set my-column -1
$ d* J9 u8 c9 r! _0 l4 E8 _, a set my-phase -16 X* k$ ~) q; C. g
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
* L. _2 ~+ Q% Y3 w) c set roads patches with3 d& j3 \) _6 o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 B* { \3 f" e+ L$ O5 ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. E2 }8 K3 Q! S: A; z* A
set intersections roads with2 D1 s, T; I! f& D9 W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' \& h1 i9 A: J3 m% p7 e0 D3 w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' x+ Z, D1 V7 g
' q! W1 U% A! J% L! t X: h ask roads [ set pcolor white ]
! f' [: f& l9 y setup-intersections ?6 S5 n- T& y2 g- m0 p9 }% d
end3 B* K' L$ n: P) Q8 G
其中定义道路的句子,如下所示,是什么意思啊?
3 v3 {/ Z1 L" Y6 I/ C! f set roads patches with& X4 u- M: a$ y; H9 G) ^3 P& j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 a. p; [3 _9 _3 T r, Q+ ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- n- U1 j8 E& m) B0 v4 Q( p/ x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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