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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。
. A9 u* L( P5 F' U+ h* ]netlogo自带的social science--traffic grid这一例子当中,
0 ?. Z- V- H! M7 E* e3 uglobals
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- q( R0 @: q7 B" P v+ d% D4 h: b grid-x-inc ;; the amount of patches in between two roads in the x direction
+ `, d3 z/ @4 K% r+ F grid-y-inc ;; the amount of patches in between two roads in the y direction0 q8 b2 l3 q0 v g% |% l
acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ Z: {0 f, {$ O0 I. l: [ ;; it is to accelerate or decelerate
; C( {7 W$ v3 a7 }; X; u4 n5 l3 Z phase ;; keeps track of the phase
& n K8 s8 y# y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 _+ Q' H( u7 y4 S' e current-light ;; the currently selected light* R/ P/ ?) u) M1 o
& I4 Z8 Y; E# r, g# l z
;; patch agentsets
. t$ W# @+ u2 t; p, U$ J intersections ;; agentset containing the patches that are intersections
g5 W% ~8 D" J4 V8 w, V9 U5 A roads ;; agentset containing the patches that are roads
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turtles-own
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! {# R) T% [7 J4 f8 M: o speed ;; the speed of the turtle8 ]! L; ?6 u: k; G
up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 b0 ]( }/ a+ n6 k. p1 A wait-time ;; the amount of time since the last time a turtle has moved
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- M6 P; I D" p: {: ypatches-own* k5 `, M& m4 T* c! r
[- Y+ I: N+ O3 \9 g6 ]
intersection? ;; true if the patch is at the intersection of two roads
6 h# M3 L7 a2 H! X green-light-up? ;; true if the green light is above the intersection. otherwise, false.9 a9 `! t( O1 F: Y
;; false for a non-intersection patches.- b- Q6 m3 j2 V0 {! V7 z' K7 e& y9 P
my-row ;; the row of the intersection counting from the upper left corner of the
& y1 P" {( A7 K' M: l ;; world. -1 for non-intersection patches.: r# Y" W, H( e; D9 l
my-column ;; the column of the intersection counting from the upper left corner of the
% D! P4 q' u; f4 ~6 [ ;; world. -1 for non-intersection patches.4 v: B7 F+ E% y* V) e: v! [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 _% j& y% Y/ M
auto? ;; whether or not this intersection will switch automatically.
, h2 z# E/ [. z5 Y7 ^0 R ;; false for non-intersection patches.3 o" d' K3 f) {! U3 a
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;;;;;;;;;;;;;;;;;;;;;;0 K: R; F" N% a, F
;; Setup Procedures ;;+ D% v; D( P6 |/ m% Q, H7 v( e
;;;;;;;;;;;;;;;;;;;;;;& R9 ]" { E! n8 O- j, ?& Z" u0 e
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;; Initialize the display by giving the global and patch variables initial values.
) b* m/ }2 k/ z( N+ ]6 V;; Create num-cars of turtles if there are enough road patches for one turtle to: w$ S. ^! h" W1 G# h. p/ u
;; be created per road patch. Set up the plots., L' e% g z0 l9 Z$ ?6 l" Z- S
to setup! k _0 Y; S) m+ d
ca' s& ?6 r, |- o0 x) O8 |( c9 t' A Q
setup-globals
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;; First we ask the patches to draw themselves and set up a few variables4 j0 B S6 w6 O. @# W
setup-patches
6 M1 ^8 c' j& u6 s- d" e$ g/ d" Z make-current one-of intersections
0 K% q5 R5 y1 f. m# h; T label-current% O- a, U; b" g8 [3 e; M N
/ R! d" m8 _" [$ p% K9 k# ? set-default-shape turtles "car"
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% [$ N9 [5 ~. \0 w& f if (num-cars > count roads)1 E" d) Y. p" }' b" ~
[
6 u9 L( ^9 [3 e1 m+ s T3 D user-message (word "There are too many cars for the amount of "
7 K! d( h' c9 x2 ]: @ "road. Either increase the amount of roads " O' x9 ?" B, Z, v) P
"by increasing the GRID-SIZE-X or "
+ o7 S6 F; A# q7 _" c% r "GRID-SIZE-Y sliders, or decrease the ": D9 T7 V: h, u
"number of cars by lowering the NUMBER slider.\n"
& w$ ?" L, V/ H* } "The setup has stopped.")
) A9 G5 e2 ~* \ stop
( [2 v" r2 p, C& |4 f# w ]
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6 @: g5 G+ q0 ~" h: R8 r ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( a r0 @# a5 ?( f5 k crt num-cars% I& l* S' e% C5 R
[
6 G3 F1 T. G& |. }0 r8 \ setup-cars% X q3 U8 u: Q2 c1 d+ I/ F
set-car-color
2 ~ f! z2 l1 O- ]' U' r record-data
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;; give the turtles an initial speed
V: O% K9 P# U% L4 w6 ?5 z4 f ask turtles [ set-car-speed ]
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reset-ticks
& Z. q) a5 \1 B: J0 z# M, yend
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! x: o* M- R; N5 T4 c8 E% m;; Initialize the global variables to appropriate values* z! \1 y* I- Y! H0 D9 x/ r
to setup-globals" p) O2 V7 d, H8 B5 F- U
set current-light nobody ;; just for now, since there are no lights yet/ C/ H6 B. l% M
set phase 0 S* d! L5 l+ x* U. g. r9 A5 H7 I7 |
set num-cars-stopped 0. h0 p {: Z: \5 u
set grid-x-inc world-width / grid-size-x z& l: O0 r+ w6 m s' e; X
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* F3 F) M2 x4 E# J* |5 Q5 A T set acceleration 0.099
( \9 x! {8 J* m; d( `end
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+ ~ A2 I( p$ \; I' {1 r& x! m;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" R5 x8 t8 P+ | ^6 w;; and initialize the traffic lights to one setting' n# x7 a! x) t# d& ]% a5 S3 `
to setup-patches
2 a3 `; \- F8 ^* C6 r ;; initialize the patch-owned variables and color the patches to a base-color F4 n: q8 f% A
ask patches
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set intersection? false
7 V/ f8 |$ V" Z1 h% Z set auto? false
, r# P2 f# O/ L5 e set green-light-up? true
) B% }, T5 l! ^* }8 f2 n! ?0 U set my-row -1! f4 ~( O: c. Q6 c; T( s3 d
set my-column -1
+ J4 I% U: R1 T' S. }4 n' v0 j$ D set my-phase -15 F0 m; A% n" [/ _ {
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets( e: p9 A4 h% B Z
set roads patches with
. C- ~, v* H/ G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) v' r5 [7 W' ^& W* t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 j. V* [* z) ?' e7 {, z8 c- N set intersections roads with8 R, W; I6 J2 e) B! V4 l8 ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* Q) \& w) p V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]/ s3 b0 h1 W2 J+ V2 \
setup-intersections0 v$ N6 z# e- X- S, e( v
end
; f F8 N0 l# H- f, B. z: U; [其中定义道路的句子,如下所示,是什么意思啊?
' M$ w5 S3 n9 P( i4 }6 S! f. e set roads patches with
$ A- w1 ~2 e( R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* _/ D( @( ^ o" E8 E) q# d8 s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! f ] T0 ]/ E1 I- e# S. y. Z
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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