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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 F8 ?$ \# w! ^8 O, G" x" l' Z
netlogo自带的social science--traffic grid这一例子当中,
# `5 N0 R4 G! ]' O& Hglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
; B; H I" ?/ {0 f0 I; y7 u grid-y-inc ;; the amount of patches in between two roads in the y direction H2 l1 h6 {1 t( P/ t9 t
acceleration ;; the constant that controls how much a car speeds up or slows down by if/ R& P0 H3 p( r
;; it is to accelerate or decelerate
1 E: N5 q( }' r/ l; U phase ;; keeps track of the phase" q( Q3 {! n2 J6 b9 w- u
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 q) `9 K/ {) J, J q" u! I
current-light ;; the currently selected light
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* \' T1 j- L- E/ S5 B! m+ [4 _ ;; patch agentsets
" | ~1 S. A/ x" j/ s intersections ;; agentset containing the patches that are intersections1 g9 L/ Z1 a' q3 p3 O2 i1 }% Y7 P8 f
roads ;; agentset containing the patches that are roads2 R/ b H$ c8 F* u* W
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turtles-own" D* @3 p4 k5 R2 Q& J; C
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speed ;; the speed of the turtle
6 |! a( ?& e- J+ b" K; L, Y up-car? ;; true if the turtle moves downwards and false if it moves to the right
: \4 k! n% \* J; ^# y- K, y/ Y. J( [* ? wait-time ;; the amount of time since the last time a turtle has moved
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% T0 L. O5 Z/ D9 Ppatches-own
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intersection? ;; true if the patch is at the intersection of two roads
5 g& T$ a' w* p c3 h green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 _5 ~7 B, p0 R- g
;; false for a non-intersection patches.4 V1 m* M+ t: l& \
my-row ;; the row of the intersection counting from the upper left corner of the0 H: a, q, G' p# I: s
;; world. -1 for non-intersection patches.8 q, X+ x% R; B. f$ o0 D) e
my-column ;; the column of the intersection counting from the upper left corner of the1 R2 H/ u% _; }0 Q- \+ N
;; world. -1 for non-intersection patches.
# s2 J. M" }2 n7 i( A- _ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# @: }1 Z; }' ^# n0 ] j1 d auto? ;; whether or not this intersection will switch automatically.
. e) w1 G( Y% H4 M ;; false for non-intersection patches.
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7 D8 o& L( b4 p% x* g
8 r4 p3 E' d& E3 y2 m" N;;;;;;;;;;;;;;;;;;;;;;
$ \. U: x' n8 z& s/ i6 O! }% X& T;; Setup Procedures ;;
$ G* W) T9 X$ o4 H7 w; c+ b$ k;;;;;;;;;;;;;;;;;;;;;;# s# h0 f+ h- U9 q9 @
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;; Initialize the display by giving the global and patch variables initial values.
. C. `5 M' b( Z' T;; Create num-cars of turtles if there are enough road patches for one turtle to7 k- k7 I$ g3 K# N
;; be created per road patch. Set up the plots.
- s1 D2 O- g/ V; S+ {to setup
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setup-globals8 c- ~5 O/ j% Q
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;; First we ask the patches to draw themselves and set up a few variables
( @* t: d& y$ ~0 M: c. u1 |* _ setup-patches
+ U6 K1 j5 T2 a7 _0 V# ^4 _ make-current one-of intersections2 K$ l: Y! B2 [, }1 w
label-current2 L! U4 h+ O1 s
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set-default-shape turtles "car"9 H2 o' `/ y4 ]) ^+ i9 K8 z
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if (num-cars > count roads)/ ?5 U# G) l" `0 l3 D
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user-message (word "There are too many cars for the amount of ", r& R- S& W5 }: N' D" l
"road. Either increase the amount of roads "
$ e2 s" f4 |7 X0 F+ L( ^& { "by increasing the GRID-SIZE-X or "
) b9 k/ {3 M- `! k "GRID-SIZE-Y sliders, or decrease the "' ?# B6 Z/ ^5 f/ G, J. _1 O
"number of cars by lowering the NUMBER slider.\n"- r% M3 t. Q. r5 Z; e/ U
"The setup has stopped.")
: a7 ~. v8 G( C4 I stop9 f/ U* r% m4 l+ J- Z; w
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8 S3 P; J0 z3 e9 |+ @, Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ H. a. n+ c" q& @* c* O crt num-cars& l( H1 E' z5 z2 O/ Q8 a
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setup-cars. b/ I8 `5 j8 H e% p X) s
set-car-color
5 g9 Y/ } u! l, V. [ record-data& \4 q# p+ S* w; t! S1 j9 U2 x
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6 f% j8 [+ m$ V/ z; J6 j) ] ;; give the turtles an initial speed
2 F8 }# F5 O" }. \ ask turtles [ set-car-speed ]; h9 H" O$ o0 |/ N2 f
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reset-ticks
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. |8 a$ J5 k( p* H% D; `6 Q;; Initialize the global variables to appropriate values
. x: p, b3 H, Q1 Y# {0 [1 u/ p3 Zto setup-globals* D( a# p. R8 I7 S
set current-light nobody ;; just for now, since there are no lights yet9 D" s% r. [7 d' i) p+ {
set phase 04 _( s6 w! _, |) ~- N6 p# ?! C; G
set num-cars-stopped 0
; J, }! R: P5 N9 Z1 K6 a/ q8 V* _ set grid-x-inc world-width / grid-size-x2 ^- ]0 A$ g9 o: s8 T* p
set grid-y-inc world-height / grid-size-y& O/ \4 w4 J& l3 ?
8 e9 A. m7 I$ @, e6 B8 N# l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! o' R( b) N9 g& O! n" O set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 q! C' f6 S$ v2 L' Y! G;; and initialize the traffic lights to one setting& h/ i& I& Q. d3 a
to setup-patches% r; K& f$ N& b; G
;; initialize the patch-owned variables and color the patches to a base-color0 C1 w9 ^0 m1 Y0 C1 ?
ask patches
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9 U& X- z% z, e set intersection? false* z; f' R6 a# r; } B, P; U
set auto? false: u/ [( l, {0 @. x k/ E! A
set green-light-up? true6 e; G7 Q b) U4 M1 [
set my-row -1
: Z9 c' l2 }% j set my-column -1; @4 k" G) R! H7 }+ F
set my-phase -1
* ~9 G/ r4 K8 I' M7 u+ M set pcolor brown + 3; P( n$ e; L: |. o/ f/ t* b
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;; initialize the global variables that hold patch agentsets
9 H; [+ P) B5 a2 T8 x6 _+ z set roads patches with
* Q- W6 q% S$ ?: W; m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) ~% D" @1 a% i6 J# i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) o+ A0 e6 d; u* n4 z. C3 h
set intersections roads with
$ _! d( e* R/ @3 C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 M! m0 N/ K1 O; y4 I! ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]* Z# u+ F, }7 s: F. f. A L
setup-intersections
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( B2 I) l, v% y1 g4 M& p" i其中定义道路的句子,如下所示,是什么意思啊?: i- ~% m d. o
set roads patches with9 x5 }6 v, [7 x$ |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' ^* H. t2 {8 ?1 l) ]+ t# v6 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( h4 Y: ~, i6 h. y1 h
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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