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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。, u4 w8 Z9 D7 d/ @! H
netlogo自带的social science--traffic grid这一例子当中,9 Q, U) d) L# g% @* u
globals5 _. z; D7 F: }+ Z1 q6 P$ w
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grid-x-inc ;; the amount of patches in between two roads in the x direction+ e0 @" v& R( ~2 V
grid-y-inc ;; the amount of patches in between two roads in the y direction
" m7 s2 |+ F4 b+ ~5 v; o; M acceleration ;; the constant that controls how much a car speeds up or slows down by if
o: h$ V0 w0 o: I3 k; x0 i ;; it is to accelerate or decelerate+ i! c- |1 u8 m' Y, }# j9 C
phase ;; keeps track of the phase
: H, ^- ^4 c# x! X* @! V8 k* b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) w. J7 f& |4 z* p; S; N! ~6 }
current-light ;; the currently selected light
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;; patch agentsets
+ b8 z0 O; g9 n& b& n intersections ;; agentset containing the patches that are intersections6 l9 L$ Q1 H9 v
roads ;; agentset containing the patches that are roads
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turtles-own
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6 B( G9 \+ L# A$ a: B+ z, I speed ;; the speed of the turtle
' S: M0 V( g& q/ [ up-car? ;; true if the turtle moves downwards and false if it moves to the right
1 T ]4 h! ^3 ^# ^9 r0 I1 v5 j wait-time ;; the amount of time since the last time a turtle has moved8 x& z: d2 W6 q) j; ~& }3 E" w
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patches-own/ u" N: G5 R# a3 U6 H
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intersection? ;; true if the patch is at the intersection of two roads
1 v& y% m- {/ E. D+ ^. z green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 q# e& a0 K8 ^* {8 n; L# G
;; false for a non-intersection patches.
5 h; D6 g/ ?+ q4 U1 H4 ?0 `- l, M _4 D my-row ;; the row of the intersection counting from the upper left corner of the H( v9 `8 k/ i$ ^+ S4 X
;; world. -1 for non-intersection patches.* x: Z3 ^) e4 g
my-column ;; the column of the intersection counting from the upper left corner of the3 X% f, g6 `8 D5 F1 d' c" E1 ~
;; world. -1 for non-intersection patches.5 N3 m2 i& \! f4 j
my-phase ;; the phase for the intersection. -1 for non-intersection patches.! d4 e4 h0 [! L% H- s5 V0 t t- K
auto? ;; whether or not this intersection will switch automatically.
( z8 V& ?5 k$ q- E8 b# j4 i* k6 X3 w ;; false for non-intersection patches./ e5 m! j$ x+ F
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4 {9 I/ t u# C; a;;;;;;;;;;;;;;;;;;;;;;% C. c2 [7 F6 X% A! T. Y# s
;; Setup Procedures ;;
* |4 b" |. @# W2 j- S8 }7 z;;;;;;;;;;;;;;;;;;;;;;
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) l! i9 |: `! I( T) r: A;; Initialize the display by giving the global and patch variables initial values.
( x% V( f' }: H3 r+ K;; Create num-cars of turtles if there are enough road patches for one turtle to
: u! u* |# U7 F; p. K;; be created per road patch. Set up the plots.
7 u; c G' ^/ {2 ]6 @to setup$ p- g2 }: @' f# j) U" ?
ca
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: [, E1 Z b) j' Y5 o8 a ;; First we ask the patches to draw themselves and set up a few variables
1 C; k* o' T) Y setup-patches
3 S8 ^1 l' B' b( Z' r" ^* u& `" ] make-current one-of intersections' ?+ x! C8 o/ B+ |/ b2 K
label-current! z2 U$ \& L- e6 O* w; ?
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set-default-shape turtles "car"( i3 d# B7 M/ G* x, y9 D) | y4 e) F. R
7 U. U0 B* z9 d; L5 I if (num-cars > count roads)1 y( q5 N/ W9 X! n
[
4 z7 C+ ]) ?" q user-message (word "There are too many cars for the amount of "- ^; ~/ n2 t% v7 P
"road. Either increase the amount of roads "
' n/ u* I8 U6 B2 S1 Y "by increasing the GRID-SIZE-X or ") I0 P% _4 ~$ g( s `) o- l
"GRID-SIZE-Y sliders, or decrease the "
, y& O' I% R8 L- ^2 v4 Q, a! u) L "number of cars by lowering the NUMBER slider.\n"8 x& T0 l. |/ Z$ l9 \* p
"The setup has stopped.")2 O& g9 u6 t+ x' W' d- `* n0 z# B
stop
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' @) d0 U$ R% }$ S3 H) y2 a ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ j& W3 Y3 Z3 D5 m2 i
crt num-cars7 p7 Y7 B1 ` C: w3 {8 T
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setup-cars; W6 a4 E G% c. _. ~4 j
set-car-color% q9 B: A8 n2 X- \. g0 k
record-data" i9 Z9 i0 M c$ J
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;; give the turtles an initial speed
/ G* L* J H* ~# W' k& t' @' H ask turtles [ set-car-speed ]
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; A- H4 }" e( w; P5 l! M) f* X [/ n reset-ticks4 R- M+ L: F! V/ t- |* j
end
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! h5 U% h9 B3 N; ]3 q5 o" w# A;; Initialize the global variables to appropriate values
- D* f# V$ }' H0 x$ O5 p7 Q3 s6 v/ Pto setup-globals
; D4 u+ g9 s5 L set current-light nobody ;; just for now, since there are no lights yet
M7 @ Y+ T, Y2 A7 H! V1 \; R- g& v% m set phase 0
+ [% P; `! i# T, y% G set num-cars-stopped 0
: T; A" V: ]# n9 n4 V set grid-x-inc world-width / grid-size-x
4 C1 c5 O8 m' |# s1 `$ B9 u set grid-y-inc world-height / grid-size-y1 x3 I" L8 ~8 Q* C2 U+ H& `
) u! t( @. w6 L' G' Z% B6 h ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; l* X+ Q9 M! ` s: M1 Q
set acceleration 0.0998 b6 G( B% X* S+ s$ F
end) S* i* D* A. I4 n+ A
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* i: e8 R" m, j$ S: u1 h, S
;; and initialize the traffic lights to one setting9 O# @: f/ n+ k' F
to setup-patches$ E7 X+ D* G8 T4 w* {
;; initialize the patch-owned variables and color the patches to a base-color
, O2 m. L- z S3 b ask patches
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/ t; m* y; ?1 s- v set intersection? false
) z7 P; C+ Q8 z1 p; p set auto? false+ e; g& ^1 ]. ^ K' ?8 g
set green-light-up? true9 Y1 p6 w! P& D0 N1 @1 y' S
set my-row -1
( R) @4 k& r2 p) q+ c& {3 g# Y" D4 `0 E8 w set my-column -1
( v8 v0 l- }" A: Y9 }. l set my-phase -1
2 O2 @6 J: K& n; b$ Z; T. {; T set pcolor brown + 31 X- f3 c, l/ K! h, I8 h
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;; initialize the global variables that hold patch agentsets# z2 u' Y% K8 i' W8 A
set roads patches with
. K4 P! i; J* o) K0 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 a1 P9 V! M7 h1 }! f, K$ O3 k (floor((pycor + max-pycor) mod grid-y-inc) = 0)], b5 k1 a6 s5 o0 x% M
set intersections roads with
3 ]; [, l. E& B+ e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) L8 k1 Z: y& O, V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end& t* L9 J) C7 K; b3 e" s
其中定义道路的句子,如下所示,是什么意思啊?6 O/ F: U9 s7 n' Z( R& P7 D8 p+ P2 d' j
set roads patches with
' A& }2 L# j+ ]& i/ G0 ]7 @/ C' ?! ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 X9 _* V. n* p" r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 K1 E% O1 Q: w' D9 k
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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