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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。, w0 n- V) F5 Z. q/ w
netlogo自带的social science--traffic grid这一例子当中,. b6 R& z2 w, L
globals
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Q3 i- M3 K' e+ S grid-x-inc ;; the amount of patches in between two roads in the x direction
& R( J2 w } J grid-y-inc ;; the amount of patches in between two roads in the y direction
: |1 I' ]( u$ _2 \& W4 t7 v acceleration ;; the constant that controls how much a car speeds up or slows down by if: F- |; j) ~0 c* O# W5 B6 r( w
;; it is to accelerate or decelerate8 `9 A2 \' N7 e1 P9 H
phase ;; keeps track of the phase
K6 P+ O; C2 e l% I i num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' N/ ~. L/ U$ `0 F current-light ;; the currently selected light5 {7 T1 n3 G* Y, x" ?* B
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;; patch agentsets w& \8 C& @2 o1 I o% D s
intersections ;; agentset containing the patches that are intersections' n' f" y" ^* ` x5 w0 G
roads ;; agentset containing the patches that are roads
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o! [5 }) ]8 T; H y* Cturtles-own
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; J9 a e1 v, G* F0 F7 f speed ;; the speed of the turtle2 v3 B( e4 ?; k' U& l m
up-car? ;; true if the turtle moves downwards and false if it moves to the right
Q3 Q( L" J6 O8 D7 f wait-time ;; the amount of time since the last time a turtle has moved
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2 r: x( j6 U8 ~patches-own
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intersection? ;; true if the patch is at the intersection of two roads
: T& B7 N( ]* O9 j green-light-up? ;; true if the green light is above the intersection. otherwise, false.# N% c: f) D* r3 g6 w! Y; a2 j
;; false for a non-intersection patches. T, R/ _6 n6 S6 n9 C j0 _5 w
my-row ;; the row of the intersection counting from the upper left corner of the
" Z) Y( {& ?$ r) q: s, `' H ;; world. -1 for non-intersection patches.
6 w3 g) F4 F: b( J0 R& A# { my-column ;; the column of the intersection counting from the upper left corner of the1 G7 b/ E" | T2 }* |% E4 B) u0 ?
;; world. -1 for non-intersection patches.
9 D( d3 C# K# G9 y! [' r# N1 s# w" X my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 E' I9 K4 k' a: E" F0 [) g
auto? ;; whether or not this intersection will switch automatically.
! P& b0 @& ]4 P3 c- ` ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 P: v. p4 }" ?;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
' M0 W& C2 O5 s2 F;; Create num-cars of turtles if there are enough road patches for one turtle to1 n2 X* H4 ]7 X" x
;; be created per road patch. Set up the plots.- n5 x ^0 z/ [6 c9 O9 ?
to setup
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" R+ U% \5 f- d9 s Y setup-globals- r; U7 [8 q m, x/ T2 {
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;; First we ask the patches to draw themselves and set up a few variables
- _4 }! X0 S3 z setup-patches7 L; r9 b, W8 g* X& L; ^
make-current one-of intersections
; i1 |5 x# Q' N1 J2 I label-current& R1 r) |# ]6 F9 Z/ V# h9 ?/ O! M* ^
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set-default-shape turtles "car"3 @" ~- _0 ]6 X% \. H5 ~
* ~7 r3 p5 F/ Z0 [8 I5 E/ u. z- ~ if (num-cars > count roads)
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) U; I' V4 x5 g+ V, P user-message (word "There are too many cars for the amount of "
& c$ e4 n) T. p* d* {. {% j "road. Either increase the amount of roads "
$ x3 u1 h( @% h0 w: j "by increasing the GRID-SIZE-X or "( |" E' |6 Q6 Y6 y1 q5 C) N
"GRID-SIZE-Y sliders, or decrease the "& N0 i$ R" m6 K7 F( ^0 C" N
"number of cars by lowering the NUMBER slider.\n"" y: h' I1 w$ V- [
"The setup has stopped.")5 }, ?4 {/ P+ }1 }3 P0 ?& j
stop- m% I7 V$ @9 a' A, ?: {* S' q$ L, S
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% Q, Z1 o2 J8 Y1 D3 Q' A
crt num-cars
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- i7 `- D7 t) U4 y" E2 J$ W setup-cars9 n+ l2 D: ?8 ]
set-car-color7 l2 z) ?7 D4 u( ]2 ]4 F5 I
record-data
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/ J8 N. h+ }+ d; n ?$ T ;; give the turtles an initial speed
8 L8 _; a3 J- F: |; ?/ q ask turtles [ set-car-speed ]- o i3 {1 K9 `% R! A0 r
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reset-ticks6 r# O! c1 {: d% l( [
end
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2 }, `/ d+ S% n3 J' Y7 g7 u+ K;; Initialize the global variables to appropriate values+ ?# ~/ i! @8 A7 \1 E
to setup-globals
# d3 p. @2 Y3 M, I set current-light nobody ;; just for now, since there are no lights yet
0 L- p, U1 \0 N" F( M set phase 0 h) g T8 A, r6 a! Q+ Q3 `7 N
set num-cars-stopped 0
& [6 r4 Y# ` z set grid-x-inc world-width / grid-size-x
6 t, x: b3 q. y9 R set grid-y-inc world-height / grid-size-y, Z& Y! B% a, T3 d
- E+ u4 m# Z J) t+ k8 C+ J ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' Q7 Z% ]6 n: Z% t
set acceleration 0.099
6 K8 ^' \, n% N6 _end Q. E+ M# k: V' i0 Z4 Q0 ?
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 N9 e7 o o' L% \- ];; and initialize the traffic lights to one setting" J L' Z0 P* H# u/ l! [+ M5 ?8 t
to setup-patches
& m/ P6 g* ?8 \/ J ;; initialize the patch-owned variables and color the patches to a base-color8 a$ ^* i7 C9 a! x9 S0 T
ask patches& i; T9 i6 @% f
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set intersection? false6 b" p9 [- }; N* @
set auto? false
1 s/ M& D! f$ Y$ q6 u# g2 o set green-light-up? true
. H8 V+ i' ?8 m7 \3 b set my-row -1& {% T( Z1 I7 r4 [8 l% ?% O: j2 \& E
set my-column -18 Y& D; i) |$ u5 @
set my-phase -1
; C/ m. k! h6 j3 @" T set pcolor brown + 3& Y% L, Q+ M4 r! ~$ W3 f5 ]" ^
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;; initialize the global variables that hold patch agentsets" D8 w, u1 G" Q8 {5 D
set roads patches with
2 J `: B$ `: v) L' r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 z$ w) E" x1 v% t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 L. F: y3 M2 _' y( Q: R- O3 Q
set intersections roads with
$ ?7 u, b9 Q* \4 ~6 ~+ o, O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 C6 u" g/ G& F' n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( r3 e) m5 C7 K3 D( j
( p2 s. ?! [- S, I ask roads [ set pcolor white ]' c# a! P7 b8 `) g$ W
setup-intersections+ ^2 w9 f& M0 q% E, w
end
+ Q# ]* M/ N! @) a: b$ d其中定义道路的句子,如下所示,是什么意思啊?+ _. S* L) a6 ~; d4 H$ }
set roads patches with( g' X2 J7 ]6 s9 C5 L* k5 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ H/ A$ w( } Y: C% w: j* `, b/ M. b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 H* j6 V1 K9 x! M1 ]
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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