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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。
% [, }, {2 m8 C% _netlogo自带的social science--traffic grid这一例子当中,
+ t, e* e" b" d1 F. o' f! @globals5 ?1 i p0 j/ F3 w7 u
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( K/ W" v, V0 [ grid-y-inc ;; the amount of patches in between two roads in the y direction
. O4 [# y3 _( N6 F8 R4 Y acceleration ;; the constant that controls how much a car speeds up or slows down by if8 u$ b; x4 [+ l- B
;; it is to accelerate or decelerate
' F3 b; J. b5 i* M/ L" E( ^. ^ phase ;; keeps track of the phase
" a; \) h* C. J; D1 T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 H2 m4 e! o+ e( T9 Y% d6 E
current-light ;; the currently selected light
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;; patch agentsets0 N7 l& k% j% Q2 S4 \* `
intersections ;; agentset containing the patches that are intersections8 i4 a- W& b" n( n/ s
roads ;; agentset containing the patches that are roads" \; r' s0 F. _2 C$ J2 _
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turtles-own5 m/ g; [5 E& W2 Q6 D
[
) h- n& `& Z- r4 V speed ;; the speed of the turtle, M9 q. U4 j. A$ S3 I+ d
up-car? ;; true if the turtle moves downwards and false if it moves to the right: U; j/ e4 a6 d! u; ~- }& M$ O. \
wait-time ;; the amount of time since the last time a turtle has moved
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% o4 Q# L4 ^9 ]patches-own
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intersection? ;; true if the patch is at the intersection of two roads
( T/ g; X p/ {' l% K/ S7 a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& h8 |2 F) v3 O8 [$ I, i- n ;; false for a non-intersection patches.; L& l$ ~$ q, W' c5 Z8 h7 ]
my-row ;; the row of the intersection counting from the upper left corner of the9 F7 L/ C& X' L
;; world. -1 for non-intersection patches.8 b: `5 D( M- m' Z; B d
my-column ;; the column of the intersection counting from the upper left corner of the- K4 T9 B1 @% ]1 U3 I: n
;; world. -1 for non-intersection patches.
1 x7 i) l: R% D; h& A# K0 J2 i my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 i3 U: _" s- S auto? ;; whether or not this intersection will switch automatically., U$ l( U$ ]* f+ |+ C i. [
;; false for non-intersection patches.' p7 `4 O" a& @ q
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;;;;;;;;;;;;;;;;;;;;;;3 n: v' V& }; H0 c
;; Setup Procedures ;;2 V/ ?# @$ A2 G7 Z4 I
;;;;;;;;;;;;;;;;;;;;;;
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9 ~+ b0 ` }* Z# O;; Initialize the display by giving the global and patch variables initial values.% p2 o J9 W& @
;; Create num-cars of turtles if there are enough road patches for one turtle to
( z9 A! h% T) b; u+ |;; be created per road patch. Set up the plots.. U; R$ k- Q- y
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
" S7 y+ v' G3 p4 X/ H' K2 | setup-patches" N+ y2 G1 A! v% r' L- e8 ?; H
make-current one-of intersections
# t7 r1 ], {3 D7 H, A O label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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; e) d5 m! u9 a. A, B user-message (word "There are too many cars for the amount of "
# [; Q. A4 S+ R) t( }4 s "road. Either increase the amount of roads "
) r. d( G: W; M8 G' y8 P3 h0 M3 [% P1 y7 m "by increasing the GRID-SIZE-X or "
0 {( ^" R( }1 E$ o. F "GRID-SIZE-Y sliders, or decrease the "
: m. B, M7 z. l4 J$ g$ q/ M) S" |% m "number of cars by lowering the NUMBER slider.\n"$ _4 [ k; C) A$ P2 T' K: e+ h
"The setup has stopped.")
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! k/ F: a6 ?8 D) F1 e7 E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- U/ D! o* c+ I: z+ A* | crt num-cars
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( v/ L1 }& {( d0 [, a setup-cars7 d5 D* l3 M6 d% C- l
set-car-color
. l1 T7 O; y, c record-data) k" ?8 o& ]5 |8 m6 Q' i) n
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;; give the turtles an initial speed
# }+ ` K* v; a M0 D# b' D ask turtles [ set-car-speed ]: i" c3 s' k! @( s6 b H) g
, t1 |! b/ t" a9 | reset-ticks
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. m) I9 H% s& T# }( Y" I;; Initialize the global variables to appropriate values
- x# \3 @; v W0 }to setup-globals1 U" z% E! v6 G
set current-light nobody ;; just for now, since there are no lights yet& h' x% s% m5 d" k
set phase 0
* }& L4 n4 `! U8 x! t set num-cars-stopped 0; ?* G* t- f" I+ {; e
set grid-x-inc world-width / grid-size-x
2 W1 S* ~/ D; B3 ?% B' ? set grid-y-inc world-height / grid-size-y \1 q1 g, Y* f4 k6 }; y5 w
* Z/ o c2 z7 a% z) I' C" P8 d' C" l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 D# i# B$ ^* ?/ y set acceleration 0.099/ R: ~ r4 d" Z. d% ^& O C
end0 o+ Q( C; B8 N6 ~. ?! j
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 ?' Z) v+ \' H9 w2 W
;; and initialize the traffic lights to one setting3 h' O: H8 M/ u; p( Q
to setup-patches
) s0 C" T+ N6 C! T* w0 Z ;; initialize the patch-owned variables and color the patches to a base-color
- L* f3 g: ?6 u0 K! k/ H; F ask patches
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set intersection? false
, ^5 P) Q& w* i1 d set auto? false: r! E* f8 B( u1 C
set green-light-up? true2 R' r' }( ]; g
set my-row -1
0 b* r4 {' U& Y2 U7 o6 n! E set my-column -1
8 K2 K; s ~; j, v1 d set my-phase -12 V* z* E6 D5 E$ k$ h6 B
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets: n* L8 r5 Z3 C# {% F# Y
set roads patches with
5 K1 _! [; g+ a- O1 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 c0 ?7 L ~2 Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 w9 [7 M/ [) X) d
set intersections roads with/ S" u) b9 {7 Q% L* s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 Z; D+ b, r3 L( a: Q* ?+ ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 _2 T3 p( k3 T0 A/ N( n
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ask roads [ set pcolor white ]
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4 x% I. j7 ?* ?) n; {9 ^% jend
' X3 N# Q5 L9 X其中定义道路的句子,如下所示,是什么意思啊?% f4 c9 e) V7 p! J
set roads patches with
+ i/ B0 [; o/ K: [; E) s3 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! V- |) s* @, x& {3 C+ L7 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 i% f2 v7 {9 c* x5 f' W. A7 R5 Q+ Y8 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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