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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。
0 Q# ]4 w, b Znetlogo自带的social science--traffic grid这一例子当中,
# f5 j2 U4 L8 sglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
. I; \. f7 d) c7 I grid-y-inc ;; the amount of patches in between two roads in the y direction- K9 E q) F1 N+ H/ |
acceleration ;; the constant that controls how much a car speeds up or slows down by if2 Y: w! \0 W! S" T' j, `5 f }
;; it is to accelerate or decelerate) S* J9 }7 e; g
phase ;; keeps track of the phase
# p* w" ^$ L& F. H1 A' K num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: k* l* _* a; r current-light ;; the currently selected light
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;; patch agentsets4 U# z5 }; S% ~8 |/ L \% J
intersections ;; agentset containing the patches that are intersections
5 t& W4 l+ @( ]" G6 N, ^ roads ;; agentset containing the patches that are roads
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turtles-own7 Q1 y( \. b- u& W- z& c5 D
[
- V2 Z$ U7 W( s0 W3 z2 b speed ;; the speed of the turtle
. o8 x' M- X! }2 K0 ^: t- i: K( M up-car? ;; true if the turtle moves downwards and false if it moves to the right; f5 o1 m8 X( K( y1 s4 L- x U
wait-time ;; the amount of time since the last time a turtle has moved
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5 ]# b. p a% b0 P W2 Gpatches-own
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2 `! }+ u% K- _/ X+ R2 o: f) K' g$ l intersection? ;; true if the patch is at the intersection of two roads
7 s& z3 w0 W* |9 e4 \ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; U7 M" }5 u7 d$ r1 r ;; false for a non-intersection patches.
. I; u9 m" q( I$ Q$ H my-row ;; the row of the intersection counting from the upper left corner of the5 z8 R; H- ?; ^% J1 i
;; world. -1 for non-intersection patches.0 {' o0 O. A4 N& E4 q8 v
my-column ;; the column of the intersection counting from the upper left corner of the
+ ^" C' a3 A$ O& N ;; world. -1 for non-intersection patches.
- w O% u% a- v$ L7 E$ A) L my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# c# J1 c! W( V) Y auto? ;; whether or not this intersection will switch automatically.8 D# X! a% r3 x& S! E
;; false for non-intersection patches.
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5 ]% R) k* b( f0 d;;;;;;;;;;;;;;;;;;;;;;5 }: Z% G6 ?$ O) `& g( m- D* v
;; Setup Procedures ;;
3 H5 _% E2 I; G& x;;;;;;;;;;;;;;;;;;;;;;
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5 p/ u# z) Q" }; V- x7 v+ { @;; Initialize the display by giving the global and patch variables initial values.
D8 B9 c% Q) S2 L;; Create num-cars of turtles if there are enough road patches for one turtle to0 U0 M7 a, ~7 i2 V1 f2 k" A
;; be created per road patch. Set up the plots., w0 Y# B M) Z# g7 o
to setup
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7 ~5 L7 O( d1 ^2 F setup-globals* l$ s5 A7 \2 i2 w7 j
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;; First we ask the patches to draw themselves and set up a few variables0 A% Z' x. P4 L7 f3 A
setup-patches5 c. _4 h8 s; p; L' o* E6 Y9 {3 Z
make-current one-of intersections. g* U+ e" D9 D% L4 S9 `
label-current( d" l2 i1 y. N, e( B" ^* O' u1 b, W4 {
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set-default-shape turtles "car"3 b7 \/ t6 s4 [, v8 k' e
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if (num-cars > count roads)
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! A) D; M q4 S! G; x9 F user-message (word "There are too many cars for the amount of "
6 u8 R6 Q" k, T8 U) d "road. Either increase the amount of roads "
1 u5 X1 b+ G6 O7 A7 w "by increasing the GRID-SIZE-X or "
- Q n8 {+ L. z( v6 P' h; [2 H "GRID-SIZE-Y sliders, or decrease the "
5 I- ^9 ?' e# y "number of cars by lowering the NUMBER slider.\n", v( j" d/ i! A5 S6 S$ l
"The setup has stopped."); B: p; \* H( b# ~+ d1 J* s3 Z
stop
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6 x" n: T) K# ~ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ Y1 C3 V' A5 A) T crt num-cars
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setup-cars+ Z$ t* ]7 J, {' T) X/ E0 o7 ^2 z
set-car-color4 s' I0 U& n0 U' i
record-data0 N3 h5 O. j; i$ l
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;; give the turtles an initial speed5 n- C, i& t" j" M
ask turtles [ set-car-speed ], m( B$ ~& Y6 j' L. j! I
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reset-ticks6 ~1 n' b7 |# p; P6 N Q1 i( o
end
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0 W0 ^9 n) z1 @: @! n$ V) i;; Initialize the global variables to appropriate values; v6 |! x2 m5 |6 ?" G4 M
to setup-globals% j2 ]2 |' ~9 T/ y
set current-light nobody ;; just for now, since there are no lights yet
; f. g7 @& L) Z0 V+ p set phase 0
0 b- \$ S. ]1 S @5 I; ^! Y set num-cars-stopped 0, P$ E, k' Q7 O! L
set grid-x-inc world-width / grid-size-x
* S2 P; Q" C6 s set grid-y-inc world-height / grid-size-y4 k; a j% b& v! |
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* n) s. Q3 @, r1 ?3 w, } set acceleration 0.099
' G0 h/ Z! E5 z6 n5 k+ ` Q1 {end" I% Z! s+ K8 i- T
- |/ X8 G0 F+ Y+ f/ D, R I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# L/ v, U/ [. R;; and initialize the traffic lights to one setting
0 t9 y. ?: }$ V. Gto setup-patches
, C+ j/ [8 n" \8 C5 s2 v% v ;; initialize the patch-owned variables and color the patches to a base-color
# `/ O. h0 I4 `9 {5 F9 m ask patches1 V$ B8 S. s$ q1 B2 W
[
( O/ h9 Q& N* y2 m set intersection? false6 f1 k$ ~) X/ z, O8 {5 g: t) T
set auto? false/ [4 i# ~4 X' Q0 L0 t4 k' d/ T
set green-light-up? true
7 i8 c, S4 \: N: N1 f4 w set my-row -1% t$ ]2 q6 Z- Q* h; F z
set my-column -1
- P2 m5 V+ M x. J set my-phase -1" _" U: S5 E" n7 k
set pcolor brown + 3( e$ q# A1 }9 |+ Z+ Q
]
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;; initialize the global variables that hold patch agentsets# P- O; L: ?- _9 ]) o4 C+ ~4 h
set roads patches with2 N" a5 f+ {% [' ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, K K9 q2 F) E# _% x. f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* B" U+ d l! x* ] set intersections roads with
2 Y2 x: t* d6 F4 o, [" A7 j8 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 J0 u" k: ~( Z) t5 h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
% E# c7 N. P3 a5 `# K) Z& R2 v setup-intersections: K/ W( @+ s) r0 C
end
8 U+ ?) u* R+ Q; n' D/ u$ f其中定义道路的句子,如下所示,是什么意思啊?
, ?9 j8 U# i. P* d H' |6 r set roads patches with9 P: Y, K0 d6 }$ R& Q }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 I" K' ~5 \1 |* M" s! V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; m, g& L; W* {
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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