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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。1 m( Y6 }7 G C6 A
netlogo自带的social science--traffic grid这一例子当中,/ n& G# ~2 H, d) F L: z0 O
globals! d' {# G9 I: o6 N
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grid-x-inc ;; the amount of patches in between two roads in the x direction! r- B8 o( z P% @, ~; p j2 _# b
grid-y-inc ;; the amount of patches in between two roads in the y direction
, C; p4 B- n* U1 _: _ acceleration ;; the constant that controls how much a car speeds up or slows down by if
d; O- q- d- f8 A8 z ;; it is to accelerate or decelerate
5 T% R `3 T0 E8 Q% g& b. A phase ;; keeps track of the phase) i9 g1 A9 g/ m! @; |! R1 ^5 w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; U: T8 \4 _7 Z0 P# b3 ~ current-light ;; the currently selected light7 N- w+ D8 S5 ~" U, ~
' t- V1 G* m5 r2 U! E" U8 b ;; patch agentsets0 O o! l' H" \2 z1 k
intersections ;; agentset containing the patches that are intersections! }; ]$ g/ g4 ~" p* u- g9 Q
roads ;; agentset containing the patches that are roads
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turtles-own( _ `2 [: G$ O% `, W: [
[
" R7 b, y9 s& H& |9 F speed ;; the speed of the turtle
, D/ J" O: K- z2 F up-car? ;; true if the turtle moves downwards and false if it moves to the right
) R% L4 K/ \& k wait-time ;; the amount of time since the last time a turtle has moved
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# J" B# \) T( Z5 cpatches-own7 U% E% F/ P( {8 e4 {" @4 f+ Y
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intersection? ;; true if the patch is at the intersection of two roads$ o( \, X1 N& h" X% Y1 ?9 L
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 J: u' m" J, S! D
;; false for a non-intersection patches.
) t# i! Y) ]5 r0 [" a- ~1 z my-row ;; the row of the intersection counting from the upper left corner of the( n) u+ }# p# V
;; world. -1 for non-intersection patches.
& j2 o! l" ^3 D% c& h my-column ;; the column of the intersection counting from the upper left corner of the! Z2 s! F5 \5 L2 u% [
;; world. -1 for non-intersection patches.
3 {" z- Q" s; m- ?* f } my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ p1 o) _& M& O4 W: z! Y# ` auto? ;; whether or not this intersection will switch automatically.! G9 L6 w5 k h8 z; B1 D v
;; false for non-intersection patches.+ o* |* _4 j- |* H& Z
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! _7 l) g+ y; j0 g, [8 E;;;;;;;;;;;;;;;;;;;;;;
3 [* ]8 z8 n J" W8 s6 D;; Setup Procedures ;;7 ^$ M' ]: b: y1 N# Q8 a
;;;;;;;;;;;;;;;;;;;;;;' J$ q0 w9 f5 i( b& `5 W+ ~
/ k/ b+ o! Z" i7 s" f& @5 V5 q;; Initialize the display by giving the global and patch variables initial values.5 ~) v- K$ d% K! T2 O
;; Create num-cars of turtles if there are enough road patches for one turtle to$ I: J! I' L3 b7 d5 a$ ~: n
;; be created per road patch. Set up the plots.( z/ g7 m, Y5 Y1 j+ }. |
to setup& w; K0 T5 }; r. `7 d1 E& L. c
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setup-globals, \ T! T- L/ W1 F4 s( P
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;; First we ask the patches to draw themselves and set up a few variables+ w6 l a* B |7 B& q, h
setup-patches9 J W+ s2 I- x, @0 z
make-current one-of intersections+ }, G9 T3 Q: l L' P6 T/ V7 u
label-current
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set-default-shape turtles "car"/ Q) A, V2 m5 E+ v
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if (num-cars > count roads)8 |3 h# m; H7 o: g# M
[
# h3 i% T3 @6 x# a1 K3 [& | user-message (word "There are too many cars for the amount of "
2 x( h( q# I$ f* P/ e) P# f "road. Either increase the amount of roads " F U1 v: {# J2 q/ {- k J
"by increasing the GRID-SIZE-X or "; T+ q; U6 \9 T6 O0 V1 d6 s! V
"GRID-SIZE-Y sliders, or decrease the "
$ l- Q6 E; r* E; I/ x "number of cars by lowering the NUMBER slider.\n"5 Q/ U% \2 X; r7 E; u
"The setup has stopped."): Y3 ^' s+ g" A. i+ O# h. Y
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 E* L# T* i1 ~ crt num-cars
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setup-cars% z. O5 b5 O, n
set-car-color7 h9 L% V. Y, ]4 `- s
record-data
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7 B* E x8 d, b8 [ ;; give the turtles an initial speed
6 E9 A; R* j- F7 N/ T/ N ask turtles [ set-car-speed ]
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; E& `5 Q0 m [$ i6 X6 B) `- M reset-ticks1 {* K0 H# O0 k a& i9 O
end( {3 i7 Q5 h0 r) y9 q" }* o
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;; Initialize the global variables to appropriate values( t, R6 V2 X& [( o! C! L& X: Q; u
to setup-globals* G8 T0 ^/ \0 ]3 o4 i
set current-light nobody ;; just for now, since there are no lights yet$ A! S+ ~0 D0 h- u: Q
set phase 0
! q b0 p+ q! O1 v0 c set num-cars-stopped 0 O: ]+ t+ U6 Z3 j1 t' `2 n# W% q
set grid-x-inc world-width / grid-size-x
$ S! P- a4 C* H! ~% K% ]; l) k2 y 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
0 M. y C& {, D) V( z) A set acceleration 0.099
9 H5 f3 l, p+ F, J9 _$ }1 g2 N8 [end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets," X: e; ~# j8 f7 i" {3 R
;; and initialize the traffic lights to one setting
3 j% i! Y! i R9 M2 W; D5 A3 |: D' Lto setup-patches/ v6 u" C& X. _. y' Q$ f
;; initialize the patch-owned variables and color the patches to a base-color1 ]5 A) J+ T& X' B/ v
ask patches) `) V. G* P G
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set intersection? false( \. k# `- k) f: x! _$ S
set auto? false$ i: Q/ v+ P! M% p: d! i; B
set green-light-up? true
# F) [' { Q/ C5 A set my-row -1
. A$ Y9 Z# @- Q; B! v" K set my-column -1, W7 O5 g W2 u
set my-phase -1
3 p7 ?9 B1 J; Y# N! T/ B+ h set pcolor brown + 3* K* k* c0 A9 ^" R0 t: H
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$ p+ m; U5 U; e( E X4 n ;; initialize the global variables that hold patch agentsets+ K* p* O. S* R2 p- k% y8 o( p: o
set roads patches with8 f$ X' `2 p' x1 P% N; I4 x; Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' J5 d9 `/ Z" f+ C) J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] x1 y- `3 s& E& W. A& U3 k
set intersections roads with
4 F3 F- ~0 G; Z7 X& ?% Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 a; {9 G/ ]/ L6 ^3 p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ L" M. R8 T1 [9 ?0 Q6 d4 B
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ask roads [ set pcolor white ]$ }, @0 v' X8 X& v3 T
setup-intersections S/ [3 p4 u% C0 s
end8 f5 M5 S* G3 \, g' {6 O* w, E& `% H
其中定义道路的句子,如下所示,是什么意思啊?
0 }' b0 O2 y0 I; d$ H2 ` set roads patches with* s2 u8 I6 s+ z6 @; l/ z' g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 O% r$ X3 k1 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 L$ ~9 V" C* l3 g+ g( ]- }: 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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