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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 C1 {* f( l2 E1 ]0 L0 Knetlogo自带的social science--traffic grid这一例子当中,
8 ^5 d) }/ @2 b. d; f/ z; Fglobals# z1 v: ?$ b6 p& {; R: K* M; ~
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grid-x-inc ;; the amount of patches in between two roads in the x direction! O6 Y! E( [* B0 x1 S* r# k5 p
grid-y-inc ;; the amount of patches in between two roads in the y direction
, E9 r% m& J9 p# W5 L$ D; x acceleration ;; the constant that controls how much a car speeds up or slows down by if4 m0 m$ ]$ G6 x! Z3 P% C
;; it is to accelerate or decelerate
! T$ t+ n1 @8 t( Z% _8 v5 M( ` | phase ;; keeps track of the phase( Z* k. P( D+ P6 k) K/ r7 I
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% H! N, ?$ j& o& k
current-light ;; the currently selected light
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;; patch agentsets
5 S% c5 e9 `# u& M& V* Q1 l intersections ;; agentset containing the patches that are intersections4 S. b( {: x3 k/ K' E% D; ?
roads ;; agentset containing the patches that are roads
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turtles-own
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# H* O1 {" Y4 P% v1 a speed ;; the speed of the turtle
( ~2 B8 |, M' V( X" Z+ D up-car? ;; true if the turtle moves downwards and false if it moves to the right" ]- e2 l5 g8 Z* M$ ^- G7 Q
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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3 p* x( C# K4 t: T& M/ f; ]; `% H. { intersection? ;; true if the patch is at the intersection of two roads/ q5 g4 b- X! Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 c$ Q6 B6 B/ g. u# g
;; false for a non-intersection patches.3 e" y- b* \2 t9 J
my-row ;; the row of the intersection counting from the upper left corner of the9 O# x& `1 M( S/ P" T
;; world. -1 for non-intersection patches.
: S4 D% e$ w6 Z7 W" }" W5 d my-column ;; the column of the intersection counting from the upper left corner of the
6 |: k7 { v; f0 x1 ^' @ ;; world. -1 for non-intersection patches.
; g3 B1 M2 L: k* Z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. z# B: f- I9 v& z2 f. E8 _ auto? ;; whether or not this intersection will switch automatically.
7 g1 _. n; q8 r2 R, B( x: \ ;; false for non-intersection patches.! \. o) U V+ g5 f" i- |, G
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. k2 Z7 y4 x+ I8 s;;;;;;;;;;;;;;;;;;;;;;8 f3 i" W9 V+ D8 @3 ]% p! r: Y
;; Setup Procedures ;;
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( _7 _/ Q( h) _/ U/ g;; Initialize the display by giving the global and patch variables initial values.6 ^: u2 d& R) h6 u# v$ H
;; Create num-cars of turtles if there are enough road patches for one turtle to
; M2 R. a7 e- y1 O;; be created per road patch. Set up the plots.
, U; s% g, h0 \! q7 ~9 @; G [8 rto setup2 |% R+ M6 q7 {) R6 c7 }
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
+ Q% [2 C$ J# l5 q; a0 Z setup-patches
, f5 k, ?1 L) f! L7 ^$ o9 z$ W0 ^ make-current one-of intersections
- Y6 m+ {* R: n0 `6 v label-current, @$ ?- K y6 P/ ~' i2 a
4 t, V& t9 L1 ~# \7 l set-default-shape turtles "car"
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if (num-cars > count roads)- H3 e* I0 J/ O+ I N7 b3 d
[
. r3 e8 Y" C0 R" Y: }% d8 B" S' W6 ?3 H user-message (word "There are too many cars for the amount of "
. ?$ R* O/ F5 `$ H) D& q "road. Either increase the amount of roads "
2 B& o6 c; c* q/ ^ Z "by increasing the GRID-SIZE-X or "* h3 A4 c" C" i! T" l
"GRID-SIZE-Y sliders, or decrease the "
\4 L% t7 Y4 d3 S% Q$ u4 i& e "number of cars by lowering the NUMBER slider.\n"
6 o' w! f% z1 d: O# a2 Z9 N1 D "The setup has stopped."), j% G( a$ N& i% r) A7 w. J) b
stop; L2 j1 G* D, e0 z
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( f0 D1 I( X* c ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 \( K t* y+ @$ V! n crt num-cars5 C: `* X! n% ]# @! r% T9 n [
[
' B# Y0 F0 C& \1 B setup-cars
4 z) z6 Z3 O( w" ~ set-car-color9 B: i% L* d! W5 H
record-data: `3 V# S% f- k! ~
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/ a4 d7 T4 \. q" C- w t ;; give the turtles an initial speed
6 S+ z0 E% M, m. j ask turtles [ set-car-speed ] V2 |- z# f' ?1 Q$ f
# L9 [- z8 i) ]" @+ \ reset-ticks
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# j8 ?5 |, d4 X! ]) ^8 J* P+ i& s( E;; Initialize the global variables to appropriate values
- {. D& C3 |7 a8 r- m! Mto setup-globals
! G% T! G2 n% R) _+ N set current-light nobody ;; just for now, since there are no lights yet
* J9 k7 I+ ]3 a0 w/ h( p set phase 0) l8 A1 R @/ |" W) N6 x2 K+ N& a
set num-cars-stopped 0& C2 [. ?2 ^- {% }% q+ u9 m$ ^) k
set grid-x-inc world-width / grid-size-x
4 N: \- ?* j, H5 v- V+ V: A. ]7 o0 z 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
, O7 v6 @0 x1 G set acceleration 0.099
5 z$ @7 B& P% E8 [) [7 p; L! X' \end
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0 r1 q$ Z1 G" N) U \4 r* j0 A6 f;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 @+ d4 r4 `/ [+ V( Y, }
;; and initialize the traffic lights to one setting4 X) k! E. v, b
to setup-patches
0 T+ t0 Z/ m% S' c ;; initialize the patch-owned variables and color the patches to a base-color
! k8 a `5 O2 `1 g8 B3 k ask patches
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0 Z' z* B* ^6 G7 [' w set intersection? false( r8 w9 r6 p+ l3 ^ L; T" ~
set auto? false# g1 |. K V/ O4 ]6 z
set green-light-up? true
9 [1 Y) P7 W2 w. A, ^ set my-row -1
% ]& b5 a- ?8 V' m* } set my-column -1
" h% }7 E" j# E* e$ J9 o# c& L set my-phase -1# E( o+ s8 ^' |
set pcolor brown + 3' }" C7 n$ q) E9 U, l
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;; initialize the global variables that hold patch agentsets
/ V# v& K8 m& j2 W1 p" L% `4 p set roads patches with9 t. E+ ^) i0 i/ A: R' r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. ^" t( X$ R7 Y7 s! C0 f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: U% l7 {3 C/ R& R0 n# ]0 j
set intersections roads with
/ o4 p2 {6 [, q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) q7 S j" Q. D7 l4 i2 W, `
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]" Y9 m/ h9 H% H0 m4 K0 N' Y1 [
setup-intersections a: v$ s; ?% I. H% h4 j$ [
end
9 M' L5 I! H# N4 H( c6 E9 C其中定义道路的句子,如下所示,是什么意思啊?7 [- ^. _ W0 B. u
set roads patches with: V, P: G0 y& X+ S1 U+ m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# E) [3 y* w* U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- L( {0 b% ^, `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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