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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 {6 d+ d; O, V# S1 u( g- x
netlogo自带的social science--traffic grid这一例子当中,, n1 V& ?- D/ j6 N/ Y
globals( |( s, _) |$ d: l3 G
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; M* E. \3 x" ?0 m. V/ W$ t7 k grid-x-inc ;; the amount of patches in between two roads in the x direction5 O7 |; H( ^0 j% O2 h' M' q
grid-y-inc ;; the amount of patches in between two roads in the y direction, R' |; ]! S: w
acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ p; u) U! Z8 S/ z% m4 z$ F ;; it is to accelerate or decelerate
3 r$ F J7 R% M/ { c" B phase ;; keeps track of the phase1 ~) w! N+ t% ~
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( S a( J5 e `* F/ ~$ s. P4 \
current-light ;; the currently selected light& K$ _" x: _7 `; `5 O' e$ x0 X
( m" D9 M/ q3 K+ u8 d ;; patch agentsets
% q3 y* ~ K4 y( J intersections ;; agentset containing the patches that are intersections# T% W# H2 Y6 Y( X1 ^; P
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle+ |1 }$ Y6 `& K' u. ]8 S1 O: W
up-car? ;; true if the turtle moves downwards and false if it moves to the right
~3 k4 B" @! T# K$ N( E* x1 _# n wait-time ;; the amount of time since the last time a turtle has moved. A8 n7 c5 ~: M3 o7 @8 h* o
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patches-own
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: n# r( T. F0 b% h0 j; x# a intersection? ;; true if the patch is at the intersection of two roads
6 G# r: g. @" X: R4 l3 z green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 m: H, j, F( t3 ?' C: r" N+ W ;; false for a non-intersection patches.
7 w5 q$ }3 t$ d& o; e- X% h- u my-row ;; the row of the intersection counting from the upper left corner of the
) B* N- f9 O" I8 h: P5 `& z n ;; world. -1 for non-intersection patches.. q" M1 w7 a4 F H# {0 D" f
my-column ;; the column of the intersection counting from the upper left corner of the8 O* z' l: L( O) `) N: n0 c6 X
;; world. -1 for non-intersection patches.
0 ], n5 G: _( Y$ q0 W M+ C* @% X S my-phase ;; the phase for the intersection. -1 for non-intersection patches./ V1 l) A# I) j+ a5 @
auto? ;; whether or not this intersection will switch automatically.
5 G) k- ]5 Z& M y1 \; e, Y ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 I3 d% d) c+ B* a;; Setup Procedures ;;3 l: N# C8 L F. i
;;;;;;;;;;;;;;;;;;;;;;
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' ?% e- n. g5 Y+ {;; Initialize the display by giving the global and patch variables initial values.
( C5 D" h) f# Y& d;; Create num-cars of turtles if there are enough road patches for one turtle to
7 ]. X T) B8 s7 @& q;; be created per road patch. Set up the plots.
P& ^3 l2 J9 V7 S7 A: w6 w6 hto setup
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3 O% A6 r# ?* O5 Z$ ^9 u1 \! ~, {% F setup-globals
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/ d6 ]& z$ Q7 @& O7 s8 @( S+ \ ;; First we ask the patches to draw themselves and set up a few variables' g+ ?' z6 U) H, u& C# z
setup-patches
9 {7 S- ~" a) l make-current one-of intersections5 S7 b$ h1 I! q$ i
label-current1 k" W2 a& ?6 [8 _0 [1 L, j: `
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set-default-shape turtles "car"
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if (num-cars > count roads)
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1 K( f- d* u9 u2 X user-message (word "There are too many cars for the amount of ", I$ a8 R% P% f$ [) {1 v# Y, z1 |
"road. Either increase the amount of roads "
1 n, A4 W# b) ~7 z. b, I; t2 U "by increasing the GRID-SIZE-X or "# e, g: t! D& Y+ l6 w
"GRID-SIZE-Y sliders, or decrease the "! p# s8 }8 o9 O
"number of cars by lowering the NUMBER slider.\n"% V6 Q& Y6 Q- y, R* \8 d
"The setup has stopped.")
2 G& U1 [9 l ^( A6 r6 r stop
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. ~5 ?, X$ Q V" ~ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 F5 k% G4 k# p6 ~% c3 }; T
crt num-cars5 `/ K2 c- Q F! F9 Q
[
7 F1 P: q$ x- a9 Y% s& ~6 r setup-cars% I% r0 V" [! |# s! ?! w2 U
set-car-color% V* F7 l& Y9 A! r" c4 Z, N
record-data
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8 _, A# `4 M' J ;; give the turtles an initial speed
0 f& G" o! i1 n( |/ J% C7 Z ask turtles [ set-car-speed ]( r/ m0 }% T! t% B( N( v
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reset-ticks) n! r! P: Y" ?& ~) U- B0 S
end
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8 J9 k' C( ^5 b8 F6 E;; Initialize the global variables to appropriate values
6 z6 e8 \/ E# G9 g8 t/ ^4 }8 Oto setup-globals" K0 v& o( O5 S5 @
set current-light nobody ;; just for now, since there are no lights yet/ o8 F2 k5 L8 T$ b h6 w+ ^4 c/ \
set phase 01 {% N* V" ]- W. _
set num-cars-stopped 0
2 k+ j9 ~7 Y& N. x set grid-x-inc world-width / grid-size-x
- @0 c8 n! k6 H2 j3 V# M7 L$ l" d set grid-y-inc world-height / grid-size-y# e9 R% ~% J' y. Y$ q7 d& m
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; G/ D& r) O% b2 O3 z9 u set acceleration 0.099: k8 _ W0 a) H7 p; i- F
end" ?* l, ?3 E7 L5 G( w+ ]
$ k2 t; ]( ^! Y6 n0 x# e;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& S4 z4 h( A" Y# h+ M& a" v
;; and initialize the traffic lights to one setting
/ a8 n2 H3 q; L7 |to setup-patches* \0 `! D+ l0 g9 a( z- M
;; initialize the patch-owned variables and color the patches to a base-color" v4 G# z5 ]& R& h" Q5 ^
ask patches
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set intersection? false0 ^7 ~& j" p& c: w& C
set auto? false6 Z. ^0 B4 G: \- ~
set green-light-up? true
) y1 E* G: k: v set my-row -1
3 o7 ^. U* R+ J: }' t. ?1 D, Q- y set my-column -11 C* g/ R i0 h7 S% p2 `
set my-phase -19 M. b/ U' Z- T
set pcolor brown + 3
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$ |2 J2 b1 Q6 S9 H+ e' `$ b ;; initialize the global variables that hold patch agentsets3 l3 ^* V/ a) k$ M
set roads patches with
. ?5 H- R/ `! [/ _1 A* K/ y9 k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 c" b0 r8 t: }7 i8 Z0 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 J, i1 G7 r7 [) K2 s set intersections roads with* ]9 D1 B8 K# M9 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. P0 C1 O' G; _6 X g; F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" b. K* `! {, n5 Q1 L' _. B ask roads [ set pcolor white ]1 J8 v' x3 a, U( g. A1 x$ h
setup-intersections
2 j C; ` p$ Y+ W$ iend
1 A+ `+ n0 y1 S3 s- s' B: S- ]+ h其中定义道路的句子,如下所示,是什么意思啊?
6 w" ^# W1 R5 l J f' D' @( F set roads patches with
, I0 k/ i5 R8 {/ u7 S _6 ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, f7 b. ^2 n1 r ~6 |+ H' }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) d9 c3 Z$ V* b9 N+ u1 q* f7 W* i" O
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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