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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。
5 y9 X+ z% s; y! |; Knetlogo自带的social science--traffic grid这一例子当中,8 t6 }+ |& g) p2 _
globals
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O( ]6 \4 H( e/ T: L4 R8 V grid-x-inc ;; the amount of patches in between two roads in the x direction( F* \: k/ o# W4 @& x) j) e7 y* b
grid-y-inc ;; the amount of patches in between two roads in the y direction) Y$ L! |& c f
acceleration ;; the constant that controls how much a car speeds up or slows down by if/ G% t3 v7 l( _ i* r
;; it is to accelerate or decelerate
4 w' n5 p% }5 N) {: F1 e phase ;; keeps track of the phase8 J1 S' v" x: M% K/ ]2 i0 `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 N$ ^0 C) q5 I8 l3 Z3 C+ F* o0 k# W current-light ;; the currently selected light
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" I1 k! |- Q. T6 d ;; patch agentsets
# k7 P( A1 ?+ \. P0 O3 F; r, X5 b intersections ;; agentset containing the patches that are intersections
" a) |/ ^5 B: P roads ;; agentset containing the patches that are roads
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turtles-own' @4 `( o% T' Q3 V4 k
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speed ;; the speed of the turtle1 {$ w' t) d* B5 X* {
up-car? ;; true if the turtle moves downwards and false if it moves to the right
z4 V$ W' Q: B- E! n wait-time ;; the amount of time since the last time a turtle has moved! i* k: Q4 P6 P3 O
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patches-own2 \( z; q% A' b. p4 [
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intersection? ;; true if the patch is at the intersection of two roads
9 v) J* z& Y* r1 N4 y, r- @ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 N; T# o6 K$ y ;; false for a non-intersection patches.( q& g5 Y* ]6 U3 V
my-row ;; the row of the intersection counting from the upper left corner of the; T/ \" R% Z" Y( N
;; world. -1 for non-intersection patches.; i* b8 e4 y) t* a/ ~
my-column ;; the column of the intersection counting from the upper left corner of the
: a" y1 Z) \. c- P/ F0 A ;; world. -1 for non-intersection patches.
1 d0 Y7 V |/ F# n" c my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ h/ h1 ?9 c. x' O auto? ;; whether or not this intersection will switch automatically.' ^% z& o8 r0 V" x& Y* L: t
;; false for non-intersection patches.6 n; G" [$ F5 w- F' ]& {
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- n8 l; `* o, i5 }) v- B: V: @;;;;;;;;;;;;;;;;;;;;;;8 A; \/ ^8 O9 d' Z) X9 K% u
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
( ~3 k- S* q8 _# P7 I;; Create num-cars of turtles if there are enough road patches for one turtle to! i8 u* f2 F& D6 ]$ E$ i+ j" t E
;; be created per road patch. Set up the plots.( d0 U7 r1 d7 y# Y Q8 S5 j- |
to setup
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. B1 e2 t/ v; r6 t setup-globals
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( A0 h' w0 |" s1 v: D0 v ;; First we ask the patches to draw themselves and set up a few variables! w: x; [0 k a" l5 f
setup-patches2 l2 N% k O+ {% j5 M9 w- W
make-current one-of intersections+ @% O2 U- {' b
label-current+ t V) S. J6 R" z& e" v$ p* D D
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set-default-shape turtles "car"6 V% L1 L% | o9 j( ^. D. J
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if (num-cars > count roads): w- ?) _6 Z$ m# w
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& _4 V! T9 v p! e2 @ user-message (word "There are too many cars for the amount of "
N0 g7 N O# r9 {, F% S* c# c "road. Either increase the amount of roads "4 O; I+ K* t- k
"by increasing the GRID-SIZE-X or "
5 w! C0 Z+ S0 S+ y+ S "GRID-SIZE-Y sliders, or decrease the "* O" L5 N& g V" ~% T7 z6 C
"number of cars by lowering the NUMBER slider.\n"
+ A. a- ~. M/ v "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 ?) x& j/ X# Y4 L6 B+ Q8 f
crt num-cars
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$ U$ [+ r! {; D! O& M setup-cars
6 I* [6 y x/ c& Z3 d8 z set-car-color1 A6 f5 ]! Z8 q! U6 d
record-data
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" U$ `3 P/ m( r+ r ;; give the turtles an initial speed
6 O# [8 X, @3 }8 I5 ~. L9 q ask turtles [ set-car-speed ]
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5 T" l/ Y0 E. J2 Q& S reset-ticks+ ]- A8 Z' T8 y! Q, B
end/ C+ c2 i& N0 L
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;; Initialize the global variables to appropriate values
8 u0 D( e/ c4 w7 |; Gto setup-globals( v" ~+ M" \; V! V( w) l" |; _) e, c8 }
set current-light nobody ;; just for now, since there are no lights yet
) Y) q; a9 t4 I$ r# G1 Z; j G set phase 0
, S$ g* T. w( {1 N set num-cars-stopped 0
9 M: W% x- x C0 T0 X* P- @& S) \ set grid-x-inc world-width / grid-size-x
. _9 H9 x' D- I. `7 R1 `( `7 u set grid-y-inc world-height / grid-size-y* v/ ?' w4 b- s [9 m* c
" X- T8 Q' C, d" l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 ]7 k! i Z/ M" W0 J0 P* i3 w
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets, x4 T4 K- G8 U
;; and initialize the traffic lights to one setting Z! |1 e% |+ Q5 H1 R' l
to setup-patches B; ?3 y8 A7 |0 @
;; initialize the patch-owned variables and color the patches to a base-color. ~$ o+ ?5 T4 L8 F+ ^& N7 D
ask patches
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set intersection? false: C2 X" f0 j2 K9 J4 G; F3 M1 l2 @
set auto? false% l, `% {" [7 h e) z M: \
set green-light-up? true
1 G: \, { L* H$ u9 W set my-row -1$ M+ k6 S. x/ d2 q
set my-column -17 S: h. j+ q3 g3 a
set my-phase -11 n7 m4 B9 q7 ~/ R
set pcolor brown + 3" _2 \, l/ k+ k9 o* E* w/ h% m- `
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;; initialize the global variables that hold patch agentsets
% g# m5 \+ U+ N* Q set roads patches with
4 O$ Z+ z( B; s8 |' f# [4 @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' X/ s! N+ x8 M* O- t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 ?* b# S5 u3 o5 R' X set intersections roads with* g$ ]# T& s! a+ M3 {! ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: x" L) a7 W* Y* M) O% Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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9 C" J2 ^6 Y" x+ F$ g ask roads [ set pcolor white ]
8 C4 |: s( m# Q: L 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?3 ^ c$ l# {5 L3 u7 l$ k& |. S( n( f* b7 V
set roads patches with! R( p" ?, |" f7 T( F" f: H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 J) S' v5 L6 s p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 _% _2 G s j; N. z* Q# ^, ]
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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