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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。1 _9 j0 l9 m& r, b$ }
netlogo自带的social science--traffic grid这一例子当中,
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grid-x-inc ;; the amount of patches in between two roads in the x direction
; a( u5 u' \. u9 c; \+ } grid-y-inc ;; the amount of patches in between two roads in the y direction! D9 d( [4 @8 K7 e; _& F
acceleration ;; the constant that controls how much a car speeds up or slows down by if1 [3 E; P* Q- v6 [7 G9 R* r
;; it is to accelerate or decelerate
; ]# x% d; B- ?0 G phase ;; keeps track of the phase: a" [2 \# Q0 i' f( A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 U! |+ \9 d9 k9 d: @ current-light ;; the currently selected light9 V) J7 W2 O# t! F0 Z' v
4 S# ]) e i: ?( |" Y: d0 E ;; patch agentsets
! Y% }: h3 H8 R, @8 X$ ~, T intersections ;; agentset containing the patches that are intersections
v+ E& c& B0 j" a) I roads ;; agentset containing the patches that are roads9 @( j5 k1 {5 u3 g) y' I: ?, b/ [
]
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turtles-own$ Q6 L# P% A. P
[
/ L* T0 S$ T- x speed ;; the speed of the turtle
' L% ?. z" p% @8 _ up-car? ;; true if the turtle moves downwards and false if it moves to the right
; x$ W$ J3 W; H5 y7 e/ 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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7 F- J' X# E: w0 R2 y- M/ ` intersection? ;; true if the patch is at the intersection of two roads# ~' r/ x- u$ e4 z
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 s% r+ z- G8 M- c) y& m3 `" v ;; false for a non-intersection patches.- K8 @ v" ?$ b$ I6 u& U
my-row ;; the row of the intersection counting from the upper left corner of the" A# D+ ?) q! S
;; world. -1 for non-intersection patches., v, n: w- {4 ?/ |
my-column ;; the column of the intersection counting from the upper left corner of the
O0 y' t0 @* c+ _/ N ;; world. -1 for non-intersection patches.: g% W, D( q; t5 |
my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 q- M+ z9 i9 z4 r5 h7 r
auto? ;; whether or not this intersection will switch automatically.: j6 q+ Y0 \1 r0 V7 |* t
;; false for non-intersection patches.
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+ O9 l- B$ k: R: r0 Z7 ^ s% d;;;;;;;;;;;;;;;;;;;;;;9 W2 R1 Y2 G( R% ^. Y* I! F
;; Setup Procedures ;;
- t7 L% M( V* F" U4 o;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.6 B8 ?8 x& { v Y4 V1 y
;; Create num-cars of turtles if there are enough road patches for one turtle to7 i; y( \6 ^/ x; B! u5 U
;; be created per road patch. Set up the plots.) b& z8 v+ c5 f# J# k0 ^5 a8 k, q
to setup9 T7 n2 i4 l3 A' I2 r! K2 @
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setup-globals2 \( r+ o6 h9 p! {/ p7 t' b! G: s- j
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;; First we ask the patches to draw themselves and set up a few variables
3 B/ d- |, _' \3 h2 J' O3 k setup-patches. q- I- g& C; r# A: |, k/ F+ i7 V
make-current one-of intersections
5 F" V5 z7 v6 h3 H0 b( ]5 A3 } label-current' W, O3 F; h$ z0 [/ C2 ]
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set-default-shape turtles "car"( {7 a7 J( m: o' m( }! H
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if (num-cars > count roads)
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7 q' K; Q- {: s/ S8 C: e! _; s( u% P user-message (word "There are too many cars for the amount of "
, y" u" U7 k9 y4 _$ W "road. Either increase the amount of roads "+ _6 w1 F2 H- C- ?' r
"by increasing the GRID-SIZE-X or "' p" m- V; K! J2 @4 c ^8 e/ d
"GRID-SIZE-Y sliders, or decrease the "
5 g6 z9 E' g4 b, Z' ?! K "number of cars by lowering the NUMBER slider.\n"
* z4 \& J- C5 l; H/ p1 J "The setup has stopped.")
! x; c: U) r1 s& f2 h' Z stop% Y$ J0 Y' L* l5 |: y4 V2 c
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! W2 h& @" Y" z! C ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; j; u8 I9 y# _; S% d1 Z" a
crt num-cars
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( F! a1 z5 p7 x* J setup-cars
# N+ Q" }1 k5 ?% M7 u7 [ set-car-color
2 r# E) M" J- I- H( V2 o3 f record-data! ^8 u1 G8 H" R( x, `: k( J( }& ~
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- a; o# {2 E Y: f ;; give the turtles an initial speed; a" Y2 ?2 w- Q/ S
ask turtles [ set-car-speed ]/ H7 {$ Z- @# G% _6 ^
* F0 p/ x4 D9 B, n: t! g) o* j! F: h reset-ticks
2 c3 n1 E& A/ r6 X0 [ Y1 xend
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;; Initialize the global variables to appropriate values6 L' ?; i; G# O! F0 L1 O* w7 i
to setup-globals0 U7 Z% Y) f- }: F9 n5 g- S
set current-light nobody ;; just for now, since there are no lights yet
3 | N/ D) n) ~' J" J2 w set phase 06 S! Z( M5 T! y& v; {; L$ i
set num-cars-stopped 0
2 o; H; ? O$ O# S9 O% D set grid-x-inc world-width / grid-size-x
y) A/ R+ T& X% C. l2 K. P2 T set grid-y-inc world-height / grid-size-y/ r7 y+ B) |& K5 B
% w7 P" _8 U' C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 ]* a" V: ~: J/ }
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# x9 V. }, x! r/ k0 h4 c: n. g;; and initialize the traffic lights to one setting+ h2 {: p; \: F' A9 w& o
to setup-patches0 n+ ]" Q- z0 L5 ]# [. g$ _# t, B M
;; initialize the patch-owned variables and color the patches to a base-color$ } [0 C0 p& W, }/ L) k
ask patches) c; Q+ W% j5 [. z
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set intersection? false7 n( q+ P5 v$ I: i q
set auto? false$ S$ ]# ^4 f# P# R9 w+ p* K
set green-light-up? true
' A# X; x2 \( O2 `3 J set my-row -1
t4 l+ E6 J" ]! }, ~8 R2 w set my-column -1" O1 C F" o/ o9 c2 [- S
set my-phase -1% y: g1 w3 b7 t
set pcolor brown + 36 K% r J, L9 u; O- `9 \% D
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0 o# _0 E: P: b7 E2 h) Q6 h ;; initialize the global variables that hold patch agentsets
5 S: R2 `- T& s6 { m; _ set roads patches with
* S# Z/ \4 C/ e; Z* l% G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ M4 O; @/ s* y6 ~# h: U4 o2 Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& K3 z7 q5 I, |0 q0 p; g1 n
set intersections roads with! y0 F3 D: [$ C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( {7 E, a$ a; B" w0 [% Z2 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 s/ g9 m J: E9 w J
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ask roads [ set pcolor white ]) v& L% L! ], P+ S2 |9 o
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?" D0 S, q/ a) a( W1 {
set roads patches with% c7 Q& _ }' b( K2 `+ A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& q6 t, S- a" z9 W) C/ y! L' A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" i @" r8 y- g4 W8 a6 B" n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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