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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。
; c6 ]( X% b( y& r$ {& w# ynetlogo自带的social science--traffic grid这一例子当中,
; Z# d5 [% `5 x) u. Kglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( L7 s F; d7 L; d' @# c) J grid-y-inc ;; the amount of patches in between two roads in the y direction# e2 S5 H( w+ L# z: r; N3 [* \+ D: f
acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 a# |3 Q. ~0 a) |+ t5 U/ C- j ;; it is to accelerate or decelerate, \. A- }- ?+ T, u' w& Z
phase ;; keeps track of the phase
/ C- O$ ? d( H0 J# w, N num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 Z- C+ E7 N7 Q* E current-light ;; the currently selected light
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;; patch agentsets8 _ O" m4 l: s! P1 m
intersections ;; agentset containing the patches that are intersections5 Z; F& S3 O& g; e
roads ;; agentset containing the patches that are roads: w: f2 l" g# P+ }
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turtles-own6 q5 N) `3 E. ]! N4 p* k& P
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speed ;; the speed of the turtle7 w& Z; b1 J3 Y
up-car? ;; true if the turtle moves downwards and false if it moves to the right/ |2 v! V$ m9 D- Q" K2 n
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 roads
7 Y2 V: Q4 n! `; t' T; s; @ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. |0 X8 Y5 V! @- A ;; false for a non-intersection patches.' ^' ~; D8 x6 j8 C' O2 v
my-row ;; the row of the intersection counting from the upper left corner of the
. \4 Y8 }4 c' G% V* @1 H$ g ;; world. -1 for non-intersection patches.6 ]' y; c- k3 I: V1 y- o3 ]3 c( P
my-column ;; the column of the intersection counting from the upper left corner of the9 Q3 P }; l2 F" d5 x9 g
;; world. -1 for non-intersection patches.
& G. ~( I" U) A; l" R2 v- V) c2 b my-phase ;; the phase for the intersection. -1 for non-intersection patches./ W0 W5 U4 l7 P5 V4 ^
auto? ;; whether or not this intersection will switch automatically.
5 f4 s6 p7 W" w5 F& Q/ J ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;% v2 h7 j/ j/ q
;; Setup Procedures ;;
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+ H$ l- w0 ^5 v7 [;; Initialize the display by giving the global and patch variables initial values.) }5 o# R8 D$ k5 @
;; Create num-cars of turtles if there are enough road patches for one turtle to
1 A, C) e' s9 Y- Q;; be created per road patch. Set up the plots.$ z' p3 t+ ]* J. [6 j8 H# h
to setup; \3 ^, c/ m& c9 {- y% K x
ca
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;; First we ask the patches to draw themselves and set up a few variables
9 [: O( q9 N7 G) m# w; t% w setup-patches
3 G, l' q" x/ ^8 X" z" _& A: J make-current one-of intersections5 K" `1 F$ j3 x. t
label-current/ U& x% f% y, F1 h" H `9 i. ]
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set-default-shape turtles "car"
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if (num-cars > count roads)
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0 j5 O# v/ g8 _) Y( q user-message (word "There are too many cars for the amount of "
( G6 e* Y' ?7 j5 k0 f2 I "road. Either increase the amount of roads "
) r2 `$ C5 n: y' _- ]/ U; s# N( v6 V "by increasing the GRID-SIZE-X or "
8 C) p3 l6 k1 s) U- D2 _) }2 b! W "GRID-SIZE-Y sliders, or decrease the "3 P- @# m7 N& H* p5 U
"number of cars by lowering the NUMBER slider.\n"
" | m: B: F3 `& \6 X6 M "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, O1 m8 b4 }3 X3 T! x
crt num-cars
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setup-cars
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record-data
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;; give the turtles an initial speed
. Z& N& e1 I# a# \2 ? ask turtles [ set-car-speed ]: |6 j7 w1 ~& u# @, |& ^
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reset-ticks
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;; Initialize the global variables to appropriate values, y6 c+ J; x! I8 l9 y
to setup-globals W- @ `; S3 v( z, ~$ _2 ~5 q
set current-light nobody ;; just for now, since there are no lights yet+ }4 Z* R2 i" q. X5 e/ ~5 i: X
set phase 0
7 D$ ~& g) S- L r3 Q( O" Y set num-cars-stopped 0/ ~9 s) C7 U+ w* |
set grid-x-inc world-width / grid-size-x8 M) l$ t; d8 h& l% {/ T
set grid-y-inc world-height / grid-size-y# k: o+ X- B/ G; J
5 r7 Z+ o8 r; J" O9 A ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ K7 `& W$ y) D" |' h
set acceleration 0.099' c+ K' p. p2 f5 R
end$ W0 N5 t% F+ k! r* P1 s
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 H7 w' n) E1 u$ i;; and initialize the traffic lights to one setting
% s& x/ i* v* Kto setup-patches
( v) x, I9 j+ h9 w3 A$ e ;; initialize the patch-owned variables and color the patches to a base-color, T% a9 y3 p" v/ ~3 `' M5 j
ask patches
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6 P' G% F4 @. y( M- { set intersection? false0 E3 G8 x9 X" l! ]
set auto? false
9 V y" ]. ]: P) A# W {; m set green-light-up? true
0 M6 G7 s! L1 } set my-row -1
4 ?: ^7 G8 f$ g- O set my-column -11 F! M4 y/ m6 O+ m. h) l5 x
set my-phase -1
9 G( `5 ]9 d( g; } set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets6 q* I1 R) e9 \) y
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' v4 U1 n- b. ]3 W t8 I7 W set intersections roads with
- c/ k- j0 b+ h } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" I+ l+ S+ D" p. t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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8 D: z" m) O4 i3 ?6 }) C2 G$ y# m$ Z* x ask roads [ set pcolor white ]+ }3 [9 \* E8 }( ~, N* T
setup-intersections
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# w7 Q% Q) f' X$ ]3 W* v其中定义道路的句子,如下所示,是什么意思啊?/ o) e0 \ s4 c$ t$ z
set roads patches with( _3 O; d1 v i( }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: L c; V: U* R$ N J' z: g6 ]+ q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 q/ r# P G* e* H6 `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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