|
|
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。+ x4 j2 G1 `0 L2 p
netlogo自带的social science--traffic grid这一例子当中,& h" z$ |" `( q
globals' U8 i8 b: F! x0 q0 Y0 q
[
. ]0 F, ]* q0 _/ p/ ^5 B5 ]# U4 @ grid-x-inc ;; the amount of patches in between two roads in the x direction
* k' }5 {( T y grid-y-inc ;; the amount of patches in between two roads in the y direction
1 o' p5 n. O1 _, V acceleration ;; the constant that controls how much a car speeds up or slows down by if- |! T" T' P& \ C
;; it is to accelerate or decelerate& S% ?7 V1 g: B/ C, u6 Q! I% Y
phase ;; keeps track of the phase$ i9 K/ _* f! b1 q3 f7 @5 E
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 q7 S# D- i R! b4 h5 S% s
current-light ;; the currently selected light6 V: ]2 w8 I' Z
' q8 Q3 L' c' y' y3 X
;; patch agentsets
' @- O2 k! e8 z; v- J3 ?- g intersections ;; agentset containing the patches that are intersections0 } w* \% B8 ~& ^ G0 _
roads ;; agentset containing the patches that are roads* a, T. X$ a/ ?
]: m) E9 |; _5 p9 H$ |4 w
. d. W, |/ E+ Y0 j9 uturtles-own H) k* X" P. \0 V8 {8 G
[& i, `/ p: |8 {; N/ k1 c; N, x
speed ;; the speed of the turtle2 _* d8 ^3 V: P
up-car? ;; true if the turtle moves downwards and false if it moves to the right; A$ E) _& E* ^1 Q
wait-time ;; the amount of time since the last time a turtle has moved8 W7 y7 c4 H% E7 U" D# V$ T
]
3 \' d7 b3 P( n
% h. A }+ r c; M) Xpatches-own( u; {6 R/ ^/ M2 ]+ R, c4 s
[# F6 i% s0 B* j f5 j: O# T, y
intersection? ;; true if the patch is at the intersection of two roads
0 a7 i" D- ~6 r green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ j) P1 q) w' A& y3 |8 g/ r ;; false for a non-intersection patches.
+ b! Q: F0 v5 a! c6 Y- S2 l/ d my-row ;; the row of the intersection counting from the upper left corner of the9 j( l( u3 I7 v" U+ q
;; world. -1 for non-intersection patches.
E7 q2 I2 t6 m0 ?8 m0 Q8 A+ U# M F my-column ;; the column of the intersection counting from the upper left corner of the3 a& p& u6 p. l( T! v& p& `9 g
;; world. -1 for non-intersection patches.2 R% x9 n0 b, W$ H
my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 l; L/ z% {) z" m, _# K3 {% A/ w& D
auto? ;; whether or not this intersection will switch automatically.
9 d8 y, h+ I* b7 N8 }8 [ ;; false for non-intersection patches.1 N9 I! Z) z: I; w
]" ]* e) R2 {& |" S7 G
* b/ s( Z( x- X o$ n: h
& P1 m" ^7 @% k1 Q! p+ s;;;;;;;;;;;;;;;;;;;;;;
9 {8 O ^, D, P3 l9 N;; Setup Procedures ;;' z8 H# @# K2 j* R
;;;;;;;;;;;;;;;;;;;;;;, F3 x+ `# k1 n( f6 E% U8 i( u
0 I: N: k! i0 v2 r1 `;; Initialize the display by giving the global and patch variables initial values.
/ B/ J+ {, b6 ]+ [6 q5 }4 H1 _7 W;; Create num-cars of turtles if there are enough road patches for one turtle to
3 L; T' o1 f+ k) K6 q5 {3 [; K; |;; be created per road patch. Set up the plots.3 m1 {- \, |8 Y
to setup
& s& j0 @4 b, ^" A6 `. X, y ca- R$ S7 G# B0 A8 X6 \8 ?
setup-globals& N$ \/ E. A7 j5 h% e% B
0 T6 A% ?2 }8 i
;; First we ask the patches to draw themselves and set up a few variables0 T* m# j. W: v; c4 Z; i9 @5 W
setup-patches$ F* U: p y; k6 X
make-current one-of intersections
6 v: r- a) e$ u1 r) S% |) C label-current
5 r0 u: c! x- b2 S& r" `- X
4 M% b: }& {6 ^; ^ set-default-shape turtles "car"
: f3 l! ~; h+ i9 @- e4 B& G A: c% E. h3 Z$ B& u
if (num-cars > count roads)
8 B2 S$ z1 `$ D) X [
; `, D0 `) B( ? user-message (word "There are too many cars for the amount of "% y2 I$ o* P7 X( n1 g; F& `) C5 T
"road. Either increase the amount of roads "; M( Z; @- t6 q3 X" a! F
"by increasing the GRID-SIZE-X or "' s% ~$ @* R: d( K
"GRID-SIZE-Y sliders, or decrease the "& B- r( P7 d0 X
"number of cars by lowering the NUMBER slider.\n"+ q3 f* Y4 B. l4 Q) t9 [) N
"The setup has stopped.")* i4 h+ m4 n/ k0 E0 G
stop
% ~0 g' d: R1 @ v: r( G ]
, n& B3 ]+ a8 z: m, V
, V* G* I! V! J3 k; m ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. w) a1 v8 Y4 r- M) f crt num-cars3 T+ e6 b/ v5 f0 \3 d
[1 _0 Q* p2 m3 {5 J
setup-cars, y, \9 x6 q) R9 X8 b
set-car-color
: e j8 o" B) a, n+ ?! {8 y0 d record-data
) ?) \ c% e* J: M7 R( q5 V ]/ c0 k# k) o0 T0 n: @8 I. u
! `- X8 E+ ~$ U5 o ;; give the turtles an initial speed
) O- P7 K( l# |( F0 m ask turtles [ set-car-speed ]4 j' n x0 Q. K. e. b1 W8 Q
* X% [$ c; q: E- ~8 a
reset-ticks, ?+ G$ l/ E9 { c
end
) {8 o4 u) Y/ ]6 z
: ]2 L* ]$ ~" y e' ]2 };; Initialize the global variables to appropriate values
/ ^2 S" M7 i3 {1 ito setup-globals5 x, n" P, v" R8 i0 V( u* c
set current-light nobody ;; just for now, since there are no lights yet6 n% _7 X J/ }7 `% g: {) H; N3 ?, N
set phase 0
4 b w X* w! y- }$ K set num-cars-stopped 0* x, K0 W/ W9 Q1 u
set grid-x-inc world-width / grid-size-x3 I6 Z( a" E5 j/ u( r4 F
set grid-y-inc world-height / grid-size-y- ~5 \2 y# @$ R& C
( Y2 s. f* j9 h+ Z# I5 {$ p2 r ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. L8 F# Z, Q' r, H set acceleration 0.099/ M7 C- V2 d2 F& `9 L* b g. X
end
2 g+ z3 w$ d- C6 Z) t8 P) m6 I% m
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& I. e+ l* I( {
;; and initialize the traffic lights to one setting* h5 H3 l9 C% L% {8 N, R
to setup-patches, `% ?! v) M& a0 H& W
;; initialize the patch-owned variables and color the patches to a base-color
2 U7 \! R1 w( {3 o# a. `' r ask patches
/ L. F% T1 L; D7 s [
5 c. @0 _) O1 N set intersection? false$ U9 F$ b6 ~# K- v# T
set auto? false
2 O' X: k6 x- ^9 k set green-light-up? true) e9 \* b* p$ }' [
set my-row -13 `- Y+ T1 Z5 e
set my-column -16 r o5 b: |4 @* t; }5 m
set my-phase -1
" x8 {% K4 T+ h6 N ~ z( J set pcolor brown + 35 R G( s/ I* b' a+ Y4 A
]( g% P l+ k4 }, ~7 v
: F' x) ~% y; T" C# B* m: P
;; initialize the global variables that hold patch agentsets8 r7 x$ a X+ d) e) Q
set roads patches with
( ^; u: L; q) R. e& h- M7 H- J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! T9 A- z" o! t9 ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. K( W3 K- V' a+ u P2 l8 f3 \: T set intersections roads with
/ C( j0 ~, E) n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% \/ E2 A, C& n (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 J/ r" L7 K9 y6 ~* D
& c4 p! a' z; z ^' h ask roads [ set pcolor white ]
4 l5 P" C+ K( H* Y5 v- ?7 | setup-intersections+ e* ^& H: A% [# y, p
end' _0 S$ ~+ Q% z. M
其中定义道路的句子,如下所示,是什么意思啊?
4 k0 e' v3 _* M2 f4 u m: [ set roads patches with
5 A5 }1 B+ P2 B, {6 a# U; Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 }4 L7 z! U o% z) O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( v+ y1 n/ A! b: d) T. R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? |
|