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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。# P, s S* z" X- @' _9 D* E* w
netlogo自带的social science--traffic grid这一例子当中,
8 u! X' c' P6 _$ @+ \! ]globals
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$ f# o- h9 `8 c. A$ i" A grid-x-inc ;; the amount of patches in between two roads in the x direction8 _; e/ F0 I+ h/ R; M5 p+ y3 u
grid-y-inc ;; the amount of patches in between two roads in the y direction& x/ A( E- p! ]) k, T5 }/ Q8 r3 W' L
acceleration ;; the constant that controls how much a car speeds up or slows down by if
# B7 N& ~4 l) O) O0 E. A' v$ v ;; it is to accelerate or decelerate
) g+ g2 F* H" \. |. @ phase ;; keeps track of the phase P: ?0 E# _. ?+ G' \ k$ g
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# a! `7 [" P2 `7 p9 R$ R current-light ;; the currently selected light4 r/ j. U3 o9 y% a. o4 t5 _
. v$ w" ^9 _" m$ e: E ;; patch agentsets- b ~% Q, Z. D) q* }% s. m7 I' I. n
intersections ;; agentset containing the patches that are intersections
/ J- O( f) D, J- Q2 u8 R% |2 Q roads ;; agentset containing the patches that are roads# E/ T7 v: u2 {# f
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turtles-own
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speed ;; the speed of the turtle
) n& j* m# T: h( M- l2 X7 q up-car? ;; true if the turtle moves downwards and false if it moves to the right5 Z F j, y+ S0 X
wait-time ;; the amount of time since the last time a turtle has moved
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) O: H# `% Q9 J6 x( hpatches-own, n2 x' m8 y0 z, S0 ?9 v2 _& |3 S
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# @) l8 y: Z' ^* E# ^! r intersection? ;; true if the patch is at the intersection of two roads3 q$ G& {' S, K* h/ [: M
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 i3 x! D8 @2 p9 W: W ;; false for a non-intersection patches.( e9 a2 C9 W2 W! Y. `
my-row ;; the row of the intersection counting from the upper left corner of the/ p$ L$ i% V3 I: A; {
;; world. -1 for non-intersection patches.' [& u/ H6 k# N) L3 _: p
my-column ;; the column of the intersection counting from the upper left corner of the; G+ W6 i) N% u m& X
;; world. -1 for non-intersection patches.
/ J/ L0 h3 @/ w( Q2 q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' B; f) s4 r/ B! G, p; k auto? ;; whether or not this intersection will switch automatically.
: E( E9 @/ H7 w% o) E" O6 j ;; false for non-intersection patches.5 ^! n' C, }/ T# p1 U
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( a' I6 r Y0 v+ K;;;;;;;;;;;;;;;;;;;;;;
2 x0 n$ }# B& \6 E! [;; Setup Procedures ;;" J1 z; q( G' @7 m
;;;;;;;;;;;;;;;;;;;;;;3 L! g7 a. M* T$ M" [4 B3 s
8 N2 @' H" F2 Y8 M' F;; Initialize the display by giving the global and patch variables initial values.
+ f* ]* ?# T2 X8 F; w;; Create num-cars of turtles if there are enough road patches for one turtle to
- L5 L0 q% S T% ~3 I( _- N5 K$ h;; be created per road patch. Set up the plots.! H8 u1 L0 I, X! f1 H
to setup
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+ g' |4 V, J" X2 V2 M setup-globals Q9 c1 G- x4 x0 b
( G- S3 c: R: m8 ]( X8 B- V# n) n. p ;; First we ask the patches to draw themselves and set up a few variables; Z! e$ z" d- A( t }& f& b
setup-patches4 L; ]# L6 o& v$ f
make-current one-of intersections
8 A4 v7 z" Q* F- f# k' H# N c label-current
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set-default-shape turtles "car"
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8 J Q7 V& ` w+ I1 x7 C if (num-cars > count roads)8 z# n5 _; C# J% R; o) d' W+ z) G
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user-message (word "There are too many cars for the amount of "
$ O3 D: Q4 ?7 Z; r3 q9 L "road. Either increase the amount of roads "5 r( W1 d! F' y5 v! P" n
"by increasing the GRID-SIZE-X or "
+ l( l0 x. z! e "GRID-SIZE-Y sliders, or decrease the "0 @( I) O2 [2 N3 b
"number of cars by lowering the NUMBER slider.\n"
9 [# O( J0 i+ U# X4 o. |: Z" N4 j "The setup has stopped.")1 I, O5 K4 c# g, T' I
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars
" l) P8 S& m( a- p set-car-color
0 N- J5 z& c% I% e, a- f) E' j record-data7 i: t# z' _- p4 m5 y1 Q7 g6 z! G
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;; give the turtles an initial speed
0 |! c4 T/ d7 J- t n# f: {$ o ask turtles [ set-car-speed ]9 b( B9 `" T) R4 g1 ]4 }- J
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reset-ticks
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;; Initialize the global variables to appropriate values
) G1 u/ r4 z3 Z* x8 J- O9 N) |2 Tto setup-globals
) J; K0 M* f7 k7 S/ H6 ? set current-light nobody ;; just for now, since there are no lights yet
* ~, e# X; d9 u1 b9 U8 J/ M k set phase 0
% Z5 e+ J. H. T set num-cars-stopped 04 |# Z2 w+ v) E
set grid-x-inc world-width / grid-size-x
3 [1 \6 z" t# f4 z# B) ]. \ 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
1 J$ R3 i5 ^0 f! @& P4 F" Q set acceleration 0.099
/ R4 S$ a. n2 H0 ]- ?/ e ?% fend
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5 j! I3 l* D$ ~3 H;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 B) I) Z, C/ C& W: Z
;; and initialize the traffic lights to one setting6 B! y/ U! b! [' N# O. ^" n
to setup-patches
, U' [6 M B `) _) r8 v1 ] ;; initialize the patch-owned variables and color the patches to a base-color1 Q! u3 P. V3 j7 |
ask patches& y9 u6 y2 ]* W" h
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set intersection? false- T2 H) W' [# h( `6 q* ^
set auto? false- M" ?5 a: l9 J: N' ]& \
set green-light-up? true$ [# K8 g4 y4 X. D) L
set my-row -1
& J" [) Y/ z/ x9 _' b$ V set my-column -1
1 F) H7 H' D- }6 d. \1 N- S( J4 K; v set my-phase -1
3 E/ J, y* T) T* z3 t- D) f set pcolor brown + 37 i0 O. K8 j$ A6 M6 \
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: |& o7 ~( q7 Y) w ;; initialize the global variables that hold patch agentsets; {4 G1 z g- a2 b: Y% f$ z. w
set roads patches with
x! R0 R/ H: s, t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 v4 Q1 ^0 g# D Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) T$ d' J/ A# j4 ] P
set intersections roads with# O, T3 a& A6 A n7 ~% c8 M$ k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ m! d4 H) E% F2 B9 E* f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- `2 p- K& d1 w3 X; ^, r% F2 w3 c
m! k& G5 v a0 L5 b ask roads [ set pcolor white ]% T2 C0 p/ d# o6 ~
setup-intersections
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5 M6 j; w: Q* q' i" _% I+ J5 e其中定义道路的句子,如下所示,是什么意思啊?
8 f/ C, E3 {9 c Y set roads patches with
' O* Z+ t. z0 ~0 \* ~: l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* j! c- J% b/ N8 r, Y2 e2 m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 J8 C/ s: q( d0 f3 j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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