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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 M! u5 u3 w j$ W/ Q1 G j6 |netlogo自带的social science--traffic grid这一例子当中,
4 Q6 W C5 @+ V* y( G* t7 h% uglobals" ]: g. Z3 ]+ T7 e X
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( L! c. l* t1 {# V; [! } grid-x-inc ;; the amount of patches in between two roads in the x direction x! [/ \, v, O
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 `4 K( g, s$ m- K9 c; R, Z acceleration ;; the constant that controls how much a car speeds up or slows down by if& g( \5 D' {0 a4 c& Y2 z
;; it is to accelerate or decelerate7 O( B5 ]. Z6 m) R0 i8 [
phase ;; keeps track of the phase* T. h( `" l0 N( i: b
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ X6 K2 R% C1 M9 W! Q$ P0 ` current-light ;; the currently selected light; y0 \ F' Y" F" V/ y+ x
) v( k6 f# c+ e3 p6 o% ?. ^4 o ;; patch agentsets
4 w! t# X n# k' C; p intersections ;; agentset containing the patches that are intersections8 d! a9 o }; ^' I8 A
roads ;; agentset containing the patches that are roads
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, E* f) S& M# i m# iturtles-own
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0 m w( l" v t! W* S: D speed ;; the speed of the turtle
. a) p7 X3 B6 E& S9 Z: v/ R up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 H# z: @! |: y, `! o$ G4 x wait-time ;; the amount of time since the last time a turtle has moved' _8 h1 h+ \) P
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads2 A- G8 t5 b' s$ @* A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
4 v, F) f$ K p ;; false for a non-intersection patches.7 y) S# ^7 m* r+ |1 _
my-row ;; the row of the intersection counting from the upper left corner of the
% o0 \0 a6 s: L0 O1 G& ~ ;; world. -1 for non-intersection patches.& G( Z1 P5 Z* [: {9 B
my-column ;; the column of the intersection counting from the upper left corner of the
' v `; e, e% @6 ?' y# o ;; world. -1 for non-intersection patches.
: N z1 B. J0 K, o- b+ b ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: Q5 @3 \5 n {, t9 W1 [) Y auto? ;; whether or not this intersection will switch automatically.
4 N" M3 w0 B5 q ;; false for non-intersection patches.: s. v9 q* e( p& x* H
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;;;;;;;;;;;;;;;;;;;;;;
1 m! @( c4 Q2 I: O0 ?9 F;; Setup Procedures ;;+ m0 U+ `. C M2 O8 ~! F- i
;;;;;;;;;;;;;;;;;;;;;;. j' P/ T3 h, ~2 J8 N& s, X
7 s$ E0 y1 [5 j;; Initialize the display by giving the global and patch variables initial values.8 P6 F# X3 s: z* z5 k) R. E$ o
;; Create num-cars of turtles if there are enough road patches for one turtle to5 x# y1 h3 K6 V8 @- y
;; be created per road patch. Set up the plots.
8 E, f" S, m# ^0 V# Wto setup
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setup-globals
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, s+ r; F# U: n& l ;; First we ask the patches to draw themselves and set up a few variables
; ]1 m3 a' h' }( e5 z setup-patches3 X; U# j! y! _0 u% t5 j7 i
make-current one-of intersections
8 k4 Q0 |7 `' ]% B* I1 N label-current2 l9 p& l" ^+ w; N. |; u5 x& C9 x
% M7 U" }+ B) \: H* b+ a/ ~ set-default-shape turtles "car"
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3 W; R# B5 f9 D& y if (num-cars > count roads)" }5 }' T* H; W) Y0 H& T3 V
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8 X3 {. f$ d( P3 i) e2 [: \ user-message (word "There are too many cars for the amount of "% O$ _$ R$ L1 F9 K9 w
"road. Either increase the amount of roads ", w( k) U+ Q4 X- M
"by increasing the GRID-SIZE-X or "9 ?8 G" E% X1 j) \/ f
"GRID-SIZE-Y sliders, or decrease the ") G5 w" b2 p! r. R: |1 }6 B
"number of cars by lowering the NUMBER slider.\n"
: v0 E* M( F) c; O% p- \ "The setup has stopped."); n8 f9 I; I S0 b6 A
stop9 y* r; s8 w9 E. N7 E1 l. o
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ C! d$ M0 `3 P: r7 W
crt num-cars: z& ?1 h! }9 ]; `
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% s$ U2 P0 L0 h2 g( g- b setup-cars
" D( U9 u; n" Y% F+ n8 y set-car-color/ m1 M+ h F; F# l( X; |; X' ]5 F! ~& Z
record-data
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;; give the turtles an initial speed) W( D& R% i$ n( |# {. z# w+ ^- x4 @
ask turtles [ set-car-speed ]
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3 Z: f6 I; n4 m& n reset-ticks
5 k( c. b8 g% z" |. o \end. ]3 F7 t7 [. b' a# [8 G8 T
+ \: D0 t" i) u7 @; b! Q0 U) \;; Initialize the global variables to appropriate values
$ v' p' k2 U7 m0 B& q4 _to setup-globals1 U0 u) X4 z. K& K3 r
set current-light nobody ;; just for now, since there are no lights yet
, a; O5 N1 K: @( J7 H: V6 ^, T9 E set phase 0
; I. s) R0 P+ V7 V0 f+ | a set num-cars-stopped 0
* z) S2 _" k: j8 R% S9 Y) P set grid-x-inc world-width / grid-size-x
0 y: i4 `3 o& _5 I set grid-y-inc world-height / grid-size-y% I3 w5 C+ X+ X7 M; a
# |& U H' y) M; ~. E: H
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" \5 p+ ~6 c( y( _+ z set acceleration 0.0990 _% T" `; u# [) ^3 N% X
end
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9 N# V. a( S! H4 o; W4 {;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- N4 F/ C8 F' O9 m' Q
;; and initialize the traffic lights to one setting
# g2 j9 _( u1 {" c* Cto setup-patches+ n; S: m+ u5 [7 @* V! A! k, l
;; initialize the patch-owned variables and color the patches to a base-color
& a' f& I; c) @" O ask patches
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set intersection? false
$ N6 u9 f% ]8 @& j! j set auto? false5 d& N+ k6 Z; t) ^
set green-light-up? true1 ]7 K0 J9 e6 E0 ]9 P$ \
set my-row -19 Y9 v c2 S/ a
set my-column -1
% ^" f( a/ G8 W" u T set my-phase -1
$ Q. m2 C; I: |3 t6 h set pcolor brown + 3
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% C) @) H6 W9 h( s& |4 u ;; initialize the global variables that hold patch agentsets
- x1 `0 V) ~ g1 x. C/ B0 ? set roads patches with; e+ I8 x0 W0 f3 g- O8 z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 f0 r! G3 q" F8 J$ `5 k2 _; K6 t- h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" ] m/ U B# g/ ^5 ? set intersections roads with
/ K1 B4 V- {# e( K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 o0 l# n" L6 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ ^6 S& E: f( J. O ask roads [ set pcolor white ]' i+ w- R' k1 C! D. P
setup-intersections7 p% k" `& o# A
end% R/ \1 j& Z2 C
其中定义道路的句子,如下所示,是什么意思啊?8 w+ x* M" n! d' u" [
set roads patches with7 q5 \+ i7 G. N6 j" |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 ]1 X0 b9 ~, h/ r$ f$ N: |5 f" c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ h/ m* j) E5 D6 i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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