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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。
5 Q; p+ A' u# b# Snetlogo自带的social science--traffic grid这一例子当中,
( Y# f1 h8 c0 [9 e5 Xglobals
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& W, ?1 {& ?, I" b2 t) M: ~ grid-x-inc ;; the amount of patches in between two roads in the x direction
# K% S- p( _1 a0 Y' `9 ^9 s$ z grid-y-inc ;; the amount of patches in between two roads in the y direction& c4 H6 a" L- R6 Y" A3 T
acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ j5 E! L9 e7 x$ r/ v4 ] ;; it is to accelerate or decelerate
3 J8 A% R0 {* P& C" e phase ;; keeps track of the phase/ ?8 v+ ^3 Y* p1 A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! G9 }! M" Z$ S
current-light ;; the currently selected light
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: i( b& C! u M9 M) o ;; patch agentsets
! v# F" v8 T/ o, m. C intersections ;; agentset containing the patches that are intersections
2 S4 o( e1 g% @# B/ Z- l roads ;; agentset containing the patches that are roads
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5 s4 A1 r) I4 k, B2 s0 Qturtles-own" n: p1 d) ^* R' z2 u* t
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speed ;; the speed of the turtle! B4 z" q$ Y6 `- b6 ^& b& T/ E
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 p9 A$ Y) s* T: m
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads4 x% l2 O3 ? Y9 Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.# g h; J. s- G: Q
;; false for a non-intersection patches.4 ^( C& U; Q% ]3 r/ D
my-row ;; the row of the intersection counting from the upper left corner of the8 D( L. x' a3 C8 t0 |
;; world. -1 for non-intersection patches.
0 X6 }1 z5 i* u8 x# a8 R my-column ;; the column of the intersection counting from the upper left corner of the
8 G' f- Q7 |& ?' i8 q ;; world. -1 for non-intersection patches.
' [' S* X1 o) W! V- ` my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 Z; I1 o4 @* G" ^2 o0 c) Z/ A$ ^& ]5 l auto? ;; whether or not this intersection will switch automatically.7 u3 M- ]% f4 z
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;7 M- a$ i2 O: P
;; Setup Procedures ;;
1 K2 n1 y1 Q2 B9 ^4 k;;;;;;;;;;;;;;;;;;;;;;
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- y* B4 X k2 F;; Initialize the display by giving the global and patch variables initial values.
7 b7 i( M% ^1 l) j$ A( O; L$ K;; Create num-cars of turtles if there are enough road patches for one turtle to
9 S- f* [$ ]' b; Q* q;; be created per road patch. Set up the plots.
r; x5 U: B! y1 K- P5 m4 ~5 eto setup
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setup-globals
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( X/ ^# d& h" K3 { \3 a; C ;; First we ask the patches to draw themselves and set up a few variables
& Q( p6 f" h- B7 b% e setup-patches/ V) F# f. F i7 Z0 ~1 F) w
make-current one-of intersections
# F; [4 c% L' g" l1 F label-current
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set-default-shape turtles "car"3 ?6 Q- B6 G2 a- m9 |
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
; |$ A; r) N5 Q& d6 ^; E "road. Either increase the amount of roads "
8 {/ T2 N4 n; M( y1 K( U "by increasing the GRID-SIZE-X or "8 s E0 e" h" n ?: E
"GRID-SIZE-Y sliders, or decrease the "$ p' y. K4 s% `5 b6 m* I
"number of cars by lowering the NUMBER slider.\n"
2 d( s! @6 x2 p "The setup has stopped.")1 W$ H J& x% G, v% d
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 w7 A$ j0 Q5 l0 r! }) M; X0 l# r crt num-cars2 D. D6 }1 |+ i6 J; `5 J
[
5 D' b- _0 N [) h: B setup-cars
0 j: s1 Q5 y" m/ m7 ~8 n, q! e set-car-color
( ^- Z/ l' a R4 ] q2 O; I2 | record-data
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. y: e$ u) Y+ X5 t! u, X3 ?9 ]* l ;; give the turtles an initial speed* k% f/ W, V: }" q; h4 l
ask turtles [ set-car-speed ]
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. h/ b7 b% R4 | reset-ticks) J/ x7 t$ U) ]/ {- v) W
end/ [1 Z/ j( u8 b; c% p
8 h5 n. y6 @+ G1 R3 Z! Z;; Initialize the global variables to appropriate values
7 s8 {2 Y2 A* O$ M& k, ^( yto setup-globals
" c, i7 ^ F; s& x/ ` set current-light nobody ;; just for now, since there are no lights yet
4 f# m [4 Y# Y/ H4 l set phase 0& |& M4 S8 s3 m- K) x
set num-cars-stopped 08 x' y( m+ q* {- ^0 G4 E- [
set grid-x-inc world-width / grid-size-x
8 M |( |, K3 u6 c: a, x set grid-y-inc world-height / grid-size-y
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& b7 S# H) v1 a# U ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary+ v; U4 d7 `! ^! j5 _8 I3 t3 |
set acceleration 0.099
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" M/ J4 u7 H) Q y: U8 U# L3 E& H;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 i1 g/ }7 |1 I6 t/ M6 a( k;; and initialize the traffic lights to one setting B, n# s( B+ v7 A- |: r
to setup-patches
1 Z1 v6 ]+ V6 T6 ~4 h- m- Q ;; initialize the patch-owned variables and color the patches to a base-color! \& C/ S/ X" r7 U8 d" ?
ask patches
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set intersection? false
, m) N8 g- F! i7 w& t5 E9 d ` set auto? false
% M% V' x( X3 H set green-light-up? true
% _% Z6 r+ A J( @ set my-row -13 t+ u o* Q, F1 u& A
set my-column -1* V, E8 u0 `9 u& `6 ]
set my-phase -1
9 z x1 I; g* S9 r, L set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
, U, s7 I% Z! I8 ~ set roads patches with& {) M( o e& R- V6 x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 m8 Q6 Z. R6 }7 ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 D V# S! w$ X: s/ n) ~
set intersections roads with
( z' d. N' \- |$ H8 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" A$ j$ H) W. ~1 u2 u* f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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- C1 R7 |, A% J6 }. G ask roads [ set pcolor white ]
+ a1 v) T( d" @, E v* q: A setup-intersections5 F6 u- P9 @( l% j" ^+ z
end2 W6 M2 \& M w" t; m8 s. |
其中定义道路的句子,如下所示,是什么意思啊?1 K4 O) c! x. E; t4 h0 e5 O# R
set roads patches with
; c# _5 y# I) w+ a, V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# p/ `) X- Q$ Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ _ }$ E# z: E$ Z6 B/ y! O% p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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