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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。$ D8 ~: q& b3 L y) K5 V
netlogo自带的social science--traffic grid这一例子当中,( W$ `* t' s, C1 N: O* E5 F5 D0 y9 I
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction" f+ A W+ B1 h3 p+ e: Y
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 K: a* U# t3 p6 X+ K) X2 b acceleration ;; the constant that controls how much a car speeds up or slows down by if3 E+ g; `# o) e; o# l
;; it is to accelerate or decelerate
9 h& {* q4 w8 Y! N3 c7 M phase ;; keeps track of the phase
f0 q' R) w ?) Z2 m0 J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 e- d( r2 v% \$ l7 v2 S2 G$ p current-light ;; the currently selected light
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' q! H" n# U* L8 n6 U7 ] ;; patch agentsets7 V) Q1 |$ Y8 z; L' V5 z* W& _
intersections ;; agentset containing the patches that are intersections
! B) Q, q6 l V4 g roads ;; agentset containing the patches that are roads9 v; @8 n8 R8 T4 O: n! L9 j2 @) U
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turtles-own" m2 ?6 r& b( n+ z' x$ _! E
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speed ;; the speed of the turtle
7 \2 Q I) J. ^* S2 `' s2 z R up-car? ;; true if the turtle moves downwards and false if it moves to the right: _, S( T' [5 o# c' C; [
wait-time ;; the amount of time since the last time a turtle has moved
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0 C2 S2 q1 f# A+ \3 \. r4 Ppatches-own
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intersection? ;; true if the patch is at the intersection of two roads
6 ~& R1 b/ H/ [' M' Q! o0 E! } green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ g# F6 [3 i! P5 }* T* [& d
;; false for a non-intersection patches.6 U0 G8 w2 N" X4 E
my-row ;; the row of the intersection counting from the upper left corner of the
3 ^" h4 M- T5 q6 X% b5 k$ y9 L ;; world. -1 for non-intersection patches.
0 s6 K5 W( d9 i% _2 w" |# } my-column ;; the column of the intersection counting from the upper left corner of the
) T/ z( p& H9 r k8 O: E/ C ;; world. -1 for non-intersection patches.
% {: u! S1 d' H2 _2 T9 U my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 `! _. M' v" k2 |, G2 Q auto? ;; whether or not this intersection will switch automatically.
$ V8 E' m# Z8 U# r" ~ ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
8 [/ C% D, R9 N% w;; Setup Procedures ;;2 o* N5 I0 s$ v3 q
;;;;;;;;;;;;;;;;;;;;;;/ x. ]0 a3 a1 [9 U
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;; Initialize the display by giving the global and patch variables initial values.6 b- f1 y! K) V" x7 e
;; Create num-cars of turtles if there are enough road patches for one turtle to
) `! `' J. |( w7 I8 y8 _;; be created per road patch. Set up the plots.4 N4 w. F8 A& Z
to setup; n5 z* c$ e8 J- B: G6 E
ca
4 U7 c; X* F5 H6 M& j6 K% _+ Z+ b setup-globals4 S. X" v! V9 J. ^. ?$ i2 }( H
- l+ V0 e x8 G. V ;; First we ask the patches to draw themselves and set up a few variables
1 V7 l, z! I! A1 P2 { setup-patches
+ F$ C9 ?: j- H+ B5 m1 Y$ A! S make-current one-of intersections
" w5 M) ~0 N) P label-current
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set-default-shape turtles "car"
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$ Y8 V( N' K3 B* x' K! a if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ": M) G" D2 |% o4 n! i$ g
"road. Either increase the amount of roads "
; k& C' F" L; _ "by increasing the GRID-SIZE-X or "
; {- Q! J4 D) g0 J: k "GRID-SIZE-Y sliders, or decrease the "
* e; W. }" d$ ~6 D "number of cars by lowering the NUMBER slider.\n": Q2 J+ f- Q. k, L0 _
"The setup has stopped.")
& w5 t( u4 V0 O& E) E stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" H! Q$ C6 e) f/ y crt num-cars
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setup-cars
) c. s8 z5 Q9 p1 P1 t0 C set-car-color: k+ S+ V# l9 C" s$ i: }
record-data' l) \4 ^* s5 _1 f3 C
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;; give the turtles an initial speed
; K6 j( G) k3 j3 s1 z5 d- F ask turtles [ set-car-speed ]" R5 \ W/ ^9 Y0 Z1 i& H
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reset-ticks2 }# i1 y1 N3 d
end' P! Y& d: t" _4 u
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;; Initialize the global variables to appropriate values. ?* B% W1 T$ A; J6 j1 S
to setup-globals
! @ p. F' L5 T( `& w5 v set current-light nobody ;; just for now, since there are no lights yet
; l9 O& V. `+ l1 B set phase 0( z) t: m( P' m2 e* C
set num-cars-stopped 0; P a" C( N& p* F. N; ]8 X
set grid-x-inc world-width / grid-size-x
$ j: B, `* Z8 ] set grid-y-inc world-height / grid-size-y
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/ }. u9 Q* m; ~# h* I: Z! c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# i' e( c7 H- v9 ~9 W set acceleration 0.0996 q( _# l n. l1 j; y
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 M2 z, r$ i' A+ I;; and initialize the traffic lights to one setting
, a! q, e- O5 q3 ^, q3 mto setup-patches3 t7 [: e$ R" ~% _4 |& d% p$ R+ l
;; initialize the patch-owned variables and color the patches to a base-color
% x7 Y: O1 q6 Q$ y ask patches: m# s' k/ Y7 R) Y1 k& c
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1 a% T' `9 O1 N$ `# w set intersection? false* O" U% A/ W4 f) z5 }/ B' k
set auto? false
) l4 s. K% I8 \& I" L3 @5 Z6 R3 @4 L set green-light-up? true
9 B! @: y$ o: c0 D4 p2 z- [ set my-row -1
5 @* j2 c4 {" M9 A+ w) I8 K set my-column -1 ]6 ~" q! t4 M% L; V$ f/ J5 p# ^# K
set my-phase -1/ [4 [; D. O3 g( k! ^
set pcolor brown + 3 ^' L( P% I9 e0 P
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. f9 l) ?4 `) f ;; initialize the global variables that hold patch agentsets
, W _& `0 a2 Q set roads patches with! b: S- d2 `! x# P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) F" @1 @; V% L+ I7 P8 X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. I! G; d" V+ ?' [9 m) x) r set intersections roads with
; \; t" m* L. G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 [0 _! J/ U1 K/ [5 m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" [' T( M3 C& @9 C ask roads [ set pcolor white ] A/ c" A! }6 `* y" k) K$ u3 E
setup-intersections( ]( K" i' x3 f- Q( F
end
6 W6 O. O7 ~9 O, t# T X( u1 ?其中定义道路的句子,如下所示,是什么意思啊?$ K' U" B- u% v+ I" U
set roads patches with; l U9 o+ s. M/ {/ c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 [' @6 a; n$ h* v' {, F! d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 t( J5 O0 j+ E B" T
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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