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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。
2 ]3 l: R: H( W, u0 H" I% O/ hnetlogo自带的social science--traffic grid这一例子当中,; C3 n# `; E' a
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 v+ H$ c$ L# U, U' A, |
grid-y-inc ;; the amount of patches in between two roads in the y direction
. O: F0 n4 w2 ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if2 u7 T& N) W% ~
;; it is to accelerate or decelerate7 L; _: G$ w7 N- m. A9 K/ e H1 \
phase ;; keeps track of the phase" H2 _/ Q5 w: s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 c2 K/ ~! z* u2 Q1 m current-light ;; the currently selected light
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8 l8 c& \# z0 g- o0 r2 S" _! `' S ;; patch agentsets9 A8 U4 A+ C4 X* |3 [1 ~
intersections ;; agentset containing the patches that are intersections1 n0 @# F& `5 L7 \8 s5 g3 Y
roads ;; agentset containing the patches that are roads/ l/ d" g0 c& |& q+ G
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turtles-own. ` \0 k" k! {* ?4 V2 M% S/ r
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speed ;; the speed of the turtle( E! |) J, B5 v: Q7 {+ h, y
up-car? ;; true if the turtle moves downwards and false if it moves to the right5 T1 N, O. g4 n. f; o8 }; w$ A0 I
wait-time ;; the amount of time since the last time a turtle has moved/ x3 o3 m/ Q0 A+ x7 a$ V# V
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0 C2 C9 i9 I5 i8 J! wpatches-own
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intersection? ;; true if the patch is at the intersection of two roads) j+ y' m& O# u; L X
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% z9 R- k8 | J# L, U0 G ;; false for a non-intersection patches.
( Q) V: c/ V) Y$ ] z3 [ my-row ;; the row of the intersection counting from the upper left corner of the
( D9 [9 ?. L+ a. c. x- }( u ;; world. -1 for non-intersection patches.
3 U3 @7 w* C3 ^$ E6 \0 K; f% Q+ ? my-column ;; the column of the intersection counting from the upper left corner of the' K$ @( o2 ?. |
;; world. -1 for non-intersection patches.
+ Y/ G; v0 h7 L* g0 B/ E" h- R% Q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& G+ [; l, H7 y auto? ;; whether or not this intersection will switch automatically.# T) G2 f7 B2 e% V# u- Q
;; false for non-intersection patches.) K7 m0 u2 ?% k4 u& J5 o
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;;;;;;;;;;;;;;;;;;;;;;1 X3 k9 s% n+ f7 l3 L
;; Setup Procedures ;;
2 ~' d* `. A, Y, o8 }2 A;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
j) F( s: l5 T* |# ?2 ]9 y;; Create num-cars of turtles if there are enough road patches for one turtle to
" t7 J! u, l Z2 S W* f$ C! W;; be created per road patch. Set up the plots.% ]" H$ H L4 K, C
to setup7 ]* f S5 @( ?4 `# ]9 a9 g \
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setup-globals9 x E& g2 g7 j g/ ]
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;; First we ask the patches to draw themselves and set up a few variables; K( E; k3 f4 T) v
setup-patches
& q5 C4 Z' n' K( a& x& y- ` make-current one-of intersections. u; l/ J9 L; N y% ^' n9 v
label-current
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set-default-shape turtles "car"
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5 L, |* A( c7 D) { if (num-cars > count roads)( O' E$ V) E0 D2 P | ?/ k0 a4 h6 j" ?
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user-message (word "There are too many cars for the amount of "
1 N0 I( S1 b P0 S a "road. Either increase the amount of roads "
6 Z/ y3 z$ ^4 }, B "by increasing the GRID-SIZE-X or "* [% @# R( x! N, }, V t \2 @
"GRID-SIZE-Y sliders, or decrease the "$ ]9 u, O$ x$ E8 K1 T9 a
"number of cars by lowering the NUMBER slider.\n"
5 E2 |: d. w' M- G/ \( N+ p' n "The setup has stopped."), }/ E$ L2 t9 x! u8 P' v$ Q& n
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
, J8 A1 g* d! i6 A1 c9 A crt num-cars( x) g- i Y+ F8 x4 n; q& n
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! y* m( h' H; T& B& J setup-cars
9 @( V; j5 E3 \; y. b set-car-color4 n' Y# i: g" `, k/ {
record-data
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;; give the turtles an initial speed
5 b% c4 T8 l+ ?9 r6 K; n ask turtles [ set-car-speed ]; t* W+ v% H: M, k* x; L6 z
. M9 }: ]( A8 q& f6 m. I) ]8 E3 k reset-ticks
& G# U- o% c Y, }2 L ` n8 H( ~end) U; X6 B+ b# w* U
Z& a$ z6 I. L! g h! o;; Initialize the global variables to appropriate values
( S# c& n5 r- Ito setup-globals; U* {8 i9 u$ l, x& `9 ?# W) v
set current-light nobody ;; just for now, since there are no lights yet
% i; s" b9 g& W7 O set phase 0
# C& o2 L# L9 _4 x0 J; S- `& v set num-cars-stopped 0
" I, O+ L1 A; |& T set grid-x-inc world-width / grid-size-x
5 W) G: `% f* g- l) ~. ?6 ]0 z set grid-y-inc world-height / grid-size-y0 T: J7 @( t7 u6 m) D: w) G; u& J
! ~7 C5 I( y! c8 d ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 {% ~3 S, w9 ?% `/ P) h
set acceleration 0.099, m! U, j0 O8 T4 C4 y
end4 v7 D+ c# V0 i+ w
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& B. G8 [+ v( {$ t% d;; and initialize the traffic lights to one setting
4 R+ h2 k! k+ I1 U# zto setup-patches
, _6 V g: V+ \( N* K. M7 Q" q ;; initialize the patch-owned variables and color the patches to a base-color( K' S: Z; y$ I% J! h: U4 Y
ask patches4 Q$ _/ L$ F+ v! J0 q7 D" g4 x6 ]6 N
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1 O+ b& J8 L& H& {3 z' V; ? set intersection? false5 s) T8 {# s1 |6 W7 z% ?3 ~
set auto? false6 y: r# L3 b& \4 a1 P; J6 s- g5 D
set green-light-up? true' g" d3 }( y: v* k; v
set my-row -1& X, d, Y0 v/ F. a
set my-column -1% {. M0 t* {- y# H) N) u" a
set my-phase -1
7 t( S6 z. L4 P+ p# b) X set pcolor brown + 33 w/ |/ |8 w2 W7 i o2 s
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;; initialize the global variables that hold patch agentsets
4 Y! k' \3 t( X( N" _1 y4 o z set roads patches with' I3 C9 i; s( M# z6 N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. }; `, ?6 T0 a8 O, y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; ~, F7 o& Q- {
set intersections roads with
/ s8 `# V, r# Q9 N& y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 Z8 F0 _* v9 a( I' _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
7 ~0 V3 G. L* n* ? setup-intersections) I# A" i9 Q( ]9 T4 [/ h; G; `# v2 T
end" ]1 R$ d# {% f
其中定义道路的句子,如下所示,是什么意思啊?/ \# Z7 @" _& C% s- c
set roads patches with% R+ q7 @( x: I$ B0 ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! j, {- R. E1 F! D5 N% q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: e N: F& w0 Q+ ^
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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