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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。4 j5 d' m, I3 k4 x2 M$ ~
netlogo自带的social science--traffic grid这一例子当中,
1 ?) L% u: R: A7 ~7 tglobals3 u7 B7 f. Y9 W, |+ A7 a
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grid-x-inc ;; the amount of patches in between two roads in the x direction
8 B* ]; A; U' D4 n9 Z; A/ ]4 J% [ grid-y-inc ;; the amount of patches in between two roads in the y direction
- v, L6 \% B; o( Z; H6 p acceleration ;; the constant that controls how much a car speeds up or slows down by if* s' _) `1 r6 c' m& ]
;; it is to accelerate or decelerate
: @, [: t" a( c0 ?) z5 z phase ;; keeps track of the phase- Z$ U3 M. C' i6 ~7 J
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' e- u. p* F3 w1 u
current-light ;; the currently selected light4 V; |+ E' g! m8 S) b( T3 [
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;; patch agentsets
3 a8 r" Q* k) B intersections ;; agentset containing the patches that are intersections
* |$ t( z; b7 ]) Z& ` roads ;; agentset containing the patches that are roads
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turtles-own& }1 m' |6 S" S/ n, d$ \& c( d6 B( F
[
' L1 G8 a) n2 U3 B' E1 B4 Z speed ;; the speed of the turtle
& Q/ P3 f/ V6 O up-car? ;; true if the turtle moves downwards and false if it moves to the right
; k' ?; m; B- S+ H0 C& [9 r wait-time ;; the amount of time since the last time a turtle has moved
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- c9 i5 w) k$ ~patches-own+ [" g2 ]& p, [2 {9 V
[
7 T8 y2 T; X% i9 W( A8 a# |5 H intersection? ;; true if the patch is at the intersection of two roads
. n }( I6 F1 B' N2 | F6 }+ T) S0 ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.: ` K1 o+ l; _- T, }
;; false for a non-intersection patches.
2 o. M2 L" E8 {# n; q% ] my-row ;; the row of the intersection counting from the upper left corner of the7 a* d% D- m5 {4 V
;; world. -1 for non-intersection patches.% Y/ J0 m1 M# U. f- D0 U2 N
my-column ;; the column of the intersection counting from the upper left corner of the& p) n% U/ Y2 I% n- Y
;; world. -1 for non-intersection patches.
1 ]; `2 Z# r# C- k) `( s my-phase ;; the phase for the intersection. -1 for non-intersection patches./ E$ ]$ T6 L& b1 m$ ]5 Q |
auto? ;; whether or not this intersection will switch automatically.
/ \) m+ u5 e( N# Y9 }( l* h ;; false for non-intersection patches.
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# x. Z0 u" ^; a7 n;;;;;;;;;;;;;;;;;;;;;;& p e' Y( @4 D( U: v6 T! u
;; Setup Procedures ;;- d; B7 A/ a! ^8 o1 F7 U
;;;;;;;;;;;;;;;;;;;;;; \' k A' z$ m
' r+ Y1 S2 z$ I( ^7 W;; Initialize the display by giving the global and patch variables initial values.* Z' C* M$ J) U4 `7 c) t1 G L+ @, N
;; Create num-cars of turtles if there are enough road patches for one turtle to ] t! p: |) H" T; ~
;; be created per road patch. Set up the plots., b) B% \1 h$ e" \
to setup
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setup-globals
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/ B% v E, @) r8 P4 ` ;; First we ask the patches to draw themselves and set up a few variables r' U" ^8 Z9 l0 [( q0 P+ {
setup-patches# X# T3 u1 i! L" y" {3 D: d R
make-current one-of intersections& P7 D0 W7 b6 t: n
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "7 g" m* i4 [5 \6 `
"road. Either increase the amount of roads "+ p; \+ H' X! c. n
"by increasing the GRID-SIZE-X or "
+ C& D9 j! m0 f; ] "GRID-SIZE-Y sliders, or decrease the "! A7 j0 y5 F# T- I( [* m
"number of cars by lowering the NUMBER slider.\n"
6 O- o. H) ^# J% H# i$ D& l "The setup has stopped.")
0 z$ _( h4 q) I4 Q& B! F stop
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4 l1 B! `6 g( \+ U7 ]1 O8 E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! \7 B2 o+ n% k. R
crt num-cars
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setup-cars
' H$ {5 s4 e# X( B" w9 X set-car-color
& J, T* _ g; R9 z0 Z+ d record-data/ e9 i9 b6 A0 W @% r# e
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;; give the turtles an initial speed8 _) x2 p, t3 t3 C/ n4 L, u* e2 v
ask turtles [ set-car-speed ]
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" Q5 ^! N" m% Y3 z3 ] reset-ticks& l1 Q; Y2 C j. Z8 b- ?
end! J/ {* Q& C) N
' J4 Y# h7 c- G1 r7 |;; Initialize the global variables to appropriate values
7 k) V( k/ A7 F2 [! mto setup-globals
+ I3 e0 j) V' X3 L1 I# w7 A$ h+ ~ set current-light nobody ;; just for now, since there are no lights yet
& I- w0 r" H% K6 _/ F! K set phase 0
3 q* O& K) B9 h$ `2 @4 V6 [" D; ~ set num-cars-stopped 0
1 W5 H4 }# h9 H1 m/ D2 A3 Q B- g set grid-x-inc world-width / grid-size-x& k/ k$ o6 j. D m) w; \% u( c
set grid-y-inc world-height / grid-size-y
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' l8 u4 K9 z! b# w& y' f4 J ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" |' r9 Z$ F3 ~8 A5 Y* E1 u( z set acceleration 0.099
+ a% {, f$ m2 gend
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% X; p' T! y; x5 F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ H. y: S7 ~) [& [% V) B
;; and initialize the traffic lights to one setting
' k2 S+ k" i! L6 _0 ?0 ]to setup-patches7 f/ U( x' o! h( Y
;; initialize the patch-owned variables and color the patches to a base-color
, w" o2 o7 D4 p$ T; J% i: u* v ask patches
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set intersection? false
Z$ {# n7 v0 C" k' U set auto? false1 z# w' ?. G9 P. V
set green-light-up? true3 c9 l! X; N- O) p
set my-row -1& d" B2 b& E$ p
set my-column -1* R' Y8 }4 |- P9 |
set my-phase -1
e9 `! F0 r' n2 T6 m set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets6 n# d& r2 `/ q
set roads patches with
: U6 X2 ?5 N$ [2 }) | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ f2 M3 s4 H" j9 g5 Q A: h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' N* \0 b4 H5 ~# K& H set intersections roads with h3 L/ Y5 r7 ?5 \* v- I5 ~6 p9 K' I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 O# [9 W+ W! v O6 B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& D$ n; z4 N5 o+ ]
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ask roads [ set pcolor white ]% h5 k0 V/ ? D1 z: R6 i7 J
setup-intersections8 h( g3 f" s3 m3 r* ~1 ^
end
( Y8 t4 y0 L1 h, U$ G: q1 e其中定义道路的句子,如下所示,是什么意思啊?3 d9 Q, e, A- Q' n
set roads patches with2 z6 P. ` p" y5 ~8 G, s! J( @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 a a1 N1 V" g+ d. ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: O( M$ S+ I6 M4 J6 R1 S. a7 @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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