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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。) F# ]; E: z' c" a1 ^
netlogo自带的social science--traffic grid这一例子当中,
0 H% W4 c7 ^& ]! J, W0 Qglobals9 O1 J' A; k' h W8 y0 S
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grid-x-inc ;; the amount of patches in between two roads in the x direction; J! S4 u( q$ y0 @$ J4 E
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 p9 f' |& ~. e6 v acceleration ;; the constant that controls how much a car speeds up or slows down by if/ b* T, K' N7 b0 f6 R
;; it is to accelerate or decelerate
7 r' l! a+ p7 [( G- g. l: a phase ;; keeps track of the phase
: O( `, i0 A, k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 @3 H, V/ d) L8 E1 n" j
current-light ;; the currently selected light9 ~; v3 y- e' i( n! p0 v
7 ^9 z( n# B8 C' B+ f$ I ;; patch agentsets* h( R% B5 E/ s9 E+ J4 I6 ?7 @
intersections ;; agentset containing the patches that are intersections
. @ l; i& [, \ roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
: C7 e4 ?1 G# z6 O5 \ up-car? ;; true if the turtle moves downwards and false if it moves to the right7 k5 r7 F' V5 O3 P8 ~
wait-time ;; the amount of time since the last time a turtle has moved0 |4 _5 F* B$ G' R1 c
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$ ~" F- H1 P! o! ]% e# bpatches-own( `3 {$ q) o4 ^1 f: v# S# _
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intersection? ;; true if the patch is at the intersection of two roads
1 o9 [' h7 C x& t; L$ v green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ t" w+ H; N/ F9 K: p. g# I ;; false for a non-intersection patches.- T+ m7 _, G" V0 U3 [! b
my-row ;; the row of the intersection counting from the upper left corner of the+ E# t* j/ |9 y, J5 Q; n1 f# K. B
;; world. -1 for non-intersection patches.
4 E; k& k1 {# J; m my-column ;; the column of the intersection counting from the upper left corner of the
: m* y+ D$ v/ q5 m) m+ F+ {' X8 e ;; world. -1 for non-intersection patches.& a1 g: ~; X: ?" d; L8 {4 H
my-phase ;; the phase for the intersection. -1 for non-intersection patches./ W0 B3 G' |+ S+ u) J% `
auto? ;; whether or not this intersection will switch automatically.2 L g$ i" f3 [* W
;; false for non-intersection patches." [$ ]& r9 L$ K& \" K( F* L7 E
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;;;;;;;;;;;;;;;;;;;;;;+ H! u4 A* ~ u
;; Setup Procedures ;;7 x7 M9 w. O+ E' F! H
;;;;;;;;;;;;;;;;;;;;;;3 ?- c; P( D. E) t. _! p2 g4 e
# ]+ a c/ o s. o2 C7 ~;; Initialize the display by giving the global and patch variables initial values.
7 N' T! \; I2 ^8 b- |) E;; Create num-cars of turtles if there are enough road patches for one turtle to, _. K( D; `# s" H2 ]
;; be created per road patch. Set up the plots.
! d+ e6 @; k8 {* ?+ \1 s% J' mto setup
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; `- q6 N) m- o7 j8 X setup-globals
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+ Q" r7 K N3 v- p* \/ F" A ;; First we ask the patches to draw themselves and set up a few variables) s6 ] O6 N% G/ G: f# r$ v) R
setup-patches. P* e4 N+ x0 P/ {5 U. C% v
make-current one-of intersections* s, L# r9 {" i' E, V
label-current/ C. u2 ^) J. l D
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set-default-shape turtles "car"
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if (num-cars > count roads)
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2 {) E( y- R- q* {. R user-message (word "There are too many cars for the amount of "
+ B+ f7 F: m. }8 l7 q+ i z+ u "road. Either increase the amount of roads ". s( h1 `6 {/ t& g" o9 }4 w
"by increasing the GRID-SIZE-X or "8 n6 x) V, b; W7 h; m) X
"GRID-SIZE-Y sliders, or decrease the ") i" m1 ^' S& n' G: `& K0 i
"number of cars by lowering the NUMBER slider.\n"
4 p6 A& L/ \( M1 Q0 [! i- \ "The setup has stopped.")0 G7 B4 h) Q0 J* L) i9 \, e9 {" I, k
stop$ c9 t: z- ~( ^& ?+ Q# ^& H
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 M$ e: A9 C( J* f4 W crt num-cars/ Q* M, i9 p0 F: h3 u
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setup-cars i7 L& u. s3 T+ q8 h
set-car-color' ?5 J; d! s% _- A8 h
record-data6 B) f7 E. j0 M9 S( U" Z- Q u
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;; give the turtles an initial speed3 U: z# ~9 a5 Y
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet0 }# D, s) \1 d; U0 C
set phase 0; c: [6 g' j. U
set num-cars-stopped 0- G) ]0 \# n, V% P) M6 K
set grid-x-inc world-width / grid-size-x% y( j& r2 {- Z* E7 ?- X8 T* d
set grid-y-inc world-height / grid-size-y
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4 z5 E, D$ v$ L, f( M; ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! B _0 K2 _" Z" H. B5 m set acceleration 0.099; P# `- f9 Y# n- P& Q: C- s& e
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 t% P r, N8 O$ S0 t5 T
;; and initialize the traffic lights to one setting
7 M" k. ]& i: yto setup-patches; [: G. E5 G! [
;; initialize the patch-owned variables and color the patches to a base-color2 u$ u# `) R; n3 h3 ~' l" g
ask patches" Q3 H' x/ [/ o" n+ v# T
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* R4 J+ `; v Q( W. e set intersection? false
+ V$ u" A, Z- O7 H* ^ set auto? false& N* b% t8 v. P( J: j$ v: z! b
set green-light-up? true
5 ]1 E& d4 P8 ~# |. U8 z% Z4 R- ? set my-row -1) T3 s' C- r$ q
set my-column -1
# `- [8 _4 N; g$ M3 l! r/ r. n- ]# F5 E set my-phase -1
; [# a2 w0 O7 L1 r set pcolor brown + 32 V3 X- x6 N6 V8 P9 K5 W2 \! M' Y9 P
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;; initialize the global variables that hold patch agentsets% V& e m0 e2 H8 H8 G: T4 W
set roads patches with! x4 \% ]% E, ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! g" w) |: }& y4 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 b1 v3 F: T6 Y5 u) I J* p
set intersections roads with* h- M; `" j4 Q' B5 K9 B6 O5 y4 D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 r3 B- ?! e7 x# K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" Q) n( f% b- P3 ~2 G% o ask roads [ set pcolor white ]1 i- p- Q0 ~8 ?! Y$ Z/ [
setup-intersections c' F( Q) g/ |) O8 a J
end% V5 N. u4 W) q: i5 M8 @5 H' f
其中定义道路的句子,如下所示,是什么意思啊?+ ?" n _) N: D. r1 u4 H: p0 l
set roads patches with* B) M$ H% s: j" {2 {7 s4 ^, E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ _; \* i: t! v1 b& }# V& e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% o8 b; r4 h. n2 g# ^. m+ P4 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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