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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。6 c) y4 s( e. M' C. S! J* [
netlogo自带的social science--traffic grid这一例子当中,
; U) U, v9 a- z1 aglobals- C$ c. T/ v' L! }
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grid-x-inc ;; the amount of patches in between two roads in the x direction& Z. I. [% o7 i4 q3 u$ h
grid-y-inc ;; the amount of patches in between two roads in the y direction6 H! j- n; n3 g: F) H; I
acceleration ;; the constant that controls how much a car speeds up or slows down by if( W8 x/ L# I* m4 P3 I
;; it is to accelerate or decelerate
1 a" o; e3 t" I# c: }, a phase ;; keeps track of the phase8 l; a/ Z& G* C, u2 W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% b1 ~6 H$ l2 w current-light ;; the currently selected light
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;; patch agentsets
* E# g9 {7 |6 g0 s" Y7 r intersections ;; agentset containing the patches that are intersections
% C1 M: p/ D" L$ u3 w* t roads ;; agentset containing the patches that are roads% }7 I( Z( ?1 w6 V. w, o9 w# A% K4 U
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& A3 ~0 `: w. a. Cturtles-own
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' q4 c7 [3 u& `) I: V speed ;; the speed of the turtle
! d+ X% l/ V/ ~: l. l7 q; U- N( a up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 e9 X1 w6 E, W5 W; [, f6 Z wait-time ;; the amount of time since the last time a turtle has moved
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0 R# U* _& }2 spatches-own' {$ D# g5 r$ x; q t
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intersection? ;; true if the patch is at the intersection of two roads7 v# `+ E9 U8 d3 N6 ?- N
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 v3 J" C2 n$ K0 b
;; false for a non-intersection patches./ L2 Y7 }4 u) Q- O# d- S7 x
my-row ;; the row of the intersection counting from the upper left corner of the
& d; r& V6 e" `2 L" ? ;; world. -1 for non-intersection patches.
5 [* k# B$ `5 ]' O% v my-column ;; the column of the intersection counting from the upper left corner of the
( u1 _& U* i1 F' }* o3 u5 ?6 Y; X" Y ;; world. -1 for non-intersection patches.$ }3 R- A3 l8 t# ^) A7 f7 x
my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 W4 U3 [/ d& l# ?
auto? ;; whether or not this intersection will switch automatically.. @' U9 \3 `+ G4 v' M2 ^$ t: F: {
;; false for non-intersection patches.: }! N4 l: B9 j) X5 y2 }
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;;;;;;;;;;;;;;;;;;;;;;
) C- w( z: B: ]; P% G+ u9 S;; Setup Procedures ;;9 @1 l0 l# H% M: x" w5 R0 } d
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.3 N6 }( M- J- z u. O( m8 \$ Q
;; Create num-cars of turtles if there are enough road patches for one turtle to. W/ y! I! D$ f" p1 q7 ~
;; be created per road patch. Set up the plots.; m$ C. v9 H0 j* e; V* q
to setup2 O* R7 g" m% p
ca
7 K6 I7 @8 g: X% b/ z* N+ w setup-globals
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/ ?$ T8 f, K1 ?. U6 t% n0 M ;; First we ask the patches to draw themselves and set up a few variables5 U- Q. Q& {( o0 Z; B2 R
setup-patches
% p1 [8 B y1 @; Z make-current one-of intersections
: K& t! F) v- c$ X5 t3 }" b. J$ N label-current
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7 t1 A, k/ f6 g0 i( f" ^$ u set-default-shape turtles "car"9 P$ m- D$ I. k' r
; ~$ S8 x8 i, H if (num-cars > count roads)* ?, @( }) k. o
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1 J( O4 U' u# v( s1 @% c user-message (word "There are too many cars for the amount of "1 o+ F, u& w x2 w1 d4 b
"road. Either increase the amount of roads "
6 o+ Z# Z3 [+ f) {: N "by increasing the GRID-SIZE-X or "0 C6 ^$ e& q2 p& i: \
"GRID-SIZE-Y sliders, or decrease the "7 [! [; T) L! e. a2 C+ g
"number of cars by lowering the NUMBER slider.\n"9 Q5 p9 W+ ]% f9 Z6 e/ L3 g
"The setup has stopped.")
! b: t3 k& J0 B) M) F stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 A8 d6 U* K \9 `/ H crt num-cars- N; |$ O; @9 B, z$ @- S
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8 G7 l9 J, R9 N% S setup-cars
7 R& P6 H. Z g3 K0 x9 c, J0 ^ set-car-color$ d9 Q& O6 j9 u0 L1 F
record-data
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;; give the turtles an initial speed; p! d8 P3 {/ {0 E
ask turtles [ set-car-speed ]
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* \* F3 V1 Q a" U! W5 _, G reset-ticks
! {2 E w, `1 O0 f/ jend
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;; Initialize the global variables to appropriate values1 E3 T4 W! d" }+ ?/ j
to setup-globals2 f& R, o* t) i+ x8 y8 [7 j
set current-light nobody ;; just for now, since there are no lights yet
* ~( A8 Y; U8 ?( d3 l9 o set phase 0( \( d! }/ H3 h! \" L/ `, F2 X! ~, {
set num-cars-stopped 0
2 n7 s5 }) u6 V' z% a' s1 X5 R set grid-x-inc world-width / grid-size-x8 z: Y. i) @1 J- D" n
set grid-y-inc world-height / grid-size-y
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7 v- G* L' ~. T. S ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- H: k9 N9 e& j set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ R4 b% j7 D5 z9 [2 ?) B. D;; and initialize the traffic lights to one setting$ w7 c8 E0 Q/ H, t) Q% D
to setup-patches+ q9 q; T9 a9 a# ?
;; initialize the patch-owned variables and color the patches to a base-color9 l. Q2 ^% i/ p/ ?9 V/ R/ F, g4 {
ask patches
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4 F3 c& F# \8 Y) `. v* x set intersection? false7 e0 ^/ m$ J" T1 C
set auto? false
. S; \% g9 M8 `9 k) P, C( j% ^ set green-light-up? true
4 o9 q- P" n x9 J! S set my-row -1
9 W j5 R% V# V. Z: z set my-column -1
# N2 _, ], W4 Y, r set my-phase -1, ~7 a$ ]: y0 v ~: R
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets: s+ p" Y2 d/ J& l O
set roads patches with$ s% i8 ? S" b( k; B7 f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 m; ]8 A1 N( A* } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 n/ q( O$ w% ?8 G; ^ set intersections roads with
, M0 `7 f5 v" Z& u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 U& m- e2 j7 b V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; j: K5 b9 ^+ P* J0 g) M ask roads [ set pcolor white ]
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1 \ g- ~) w' ?* a4 F8 e# e* \5 j% ]+ |其中定义道路的句子,如下所示,是什么意思啊?
& _: p0 A: N7 ]2 \" u set roads patches with
- f8 p" `9 f" n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 I+ d+ t$ C; w8 ]8 U H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 X+ \6 k6 l8 F% R5 {5 Q, [$ r; s
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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