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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。 [+ v! i# g& x
netlogo自带的social science--traffic grid这一例子当中,
0 R8 F! G$ y' f) \8 o Cglobals7 B! O5 X9 }% j& ^2 V# D4 E
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 P V1 F+ ~1 q% _2 U4 y
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 r5 r6 R& Y$ S6 Z/ o) l- v7 ? acceleration ;; the constant that controls how much a car speeds up or slows down by if8 _ D6 k& N$ }; @$ B6 Q" ]
;; it is to accelerate or decelerate
; z1 S8 e, g9 i7 p: X z phase ;; keeps track of the phase' Z! h( |) M+ s- _ e I+ S7 r
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 M" {( x7 G. V0 [# u- r current-light ;; the currently selected light3 W n/ j0 }6 m% O# _, `: S7 _
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;; patch agentsets2 d6 y$ R4 P$ e7 q8 N3 R
intersections ;; agentset containing the patches that are intersections
r* ~; M" [* t- P% X roads ;; agentset containing the patches that are roads2 a; l- O/ `3 f( e
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turtles-own7 M5 ^: G, K; [! X
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speed ;; the speed of the turtle
. p" l: n: l% E$ i3 s) Y5 b up-car? ;; true if the turtle moves downwards and false if it moves to the right# Q: ^) g& h6 M0 j+ ?% d/ R/ d
wait-time ;; the amount of time since the last time a turtle has moved3 e5 S$ q& ?' w ?. Y0 B6 g5 `& Y
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patches-own
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9 F& P: B9 x$ r- j intersection? ;; true if the patch is at the intersection of two roads7 b# v- E0 B" A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 b: V; i: j- P: N ;; false for a non-intersection patches.
4 z) l8 @- P, L1 W" Y4 { my-row ;; the row of the intersection counting from the upper left corner of the X* R- @. K, g6 z, d& r4 G* z+ Z
;; world. -1 for non-intersection patches.
% v# U. i' i4 g my-column ;; the column of the intersection counting from the upper left corner of the
0 O1 w) s5 M2 w# A4 c ;; world. -1 for non-intersection patches.7 I H4 T6 R$ v$ R$ p/ c9 w3 C$ _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% @- x/ S0 m; ^1 [4 } auto? ;; whether or not this intersection will switch automatically.
" l, q& J, W8 p3 J6 | ;; false for non-intersection patches.& w" S& [. @% `0 w
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;;;;;;;;;;;;;;;;;;;;;;/ K* G) x" D& F: i
;; Setup Procedures ;;
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9 E* S# R% k) t) M; t, Q/ t;; Initialize the display by giving the global and patch variables initial values./ y3 r! r$ D* t: y2 w' |) E6 g
;; Create num-cars of turtles if there are enough road patches for one turtle to1 X+ o' z, e/ u- z3 F$ n4 R3 Y! n
;; be created per road patch. Set up the plots.
+ _: P3 Q( p2 L6 ~' \( g" l& W5 Rto setup) P6 X& F2 Y$ P, A4 N4 l6 Q4 ]
ca* a/ r2 H8 d) y
setup-globals2 y! s9 W h4 J- X2 Y
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;; First we ask the patches to draw themselves and set up a few variables
7 F: ?( ^% X2 T! v( J/ q8 ~ setup-patches$ A% Q* T6 J4 c2 T* c- a
make-current one-of intersections
9 T$ p* f$ M, W$ Q: n. X3 b label-current1 V2 N2 {" l. d j7 A# r! u
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set-default-shape turtles "car"
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if (num-cars > count roads)- B2 L L7 B* T. n5 k. j
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user-message (word "There are too many cars for the amount of "! P! w* c6 p; B+ _( G
"road. Either increase the amount of roads "
: K6 }1 q: E& q3 i "by increasing the GRID-SIZE-X or "0 l1 A5 V8 B1 ~1 x
"GRID-SIZE-Y sliders, or decrease the "' E y6 y) I) d9 P/ S( Q2 \
"number of cars by lowering the NUMBER slider.\n"
M, T- Z# B% i( y "The setup has stopped.")
! ]' g) Y1 r/ j% Z4 P+ x8 i5 R stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. @4 \/ C, M4 N1 q: H crt num-cars4 V; w! d# C. c( {8 D
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setup-cars
, T Z$ B* Y. C set-car-color
2 R8 X; w1 e7 ]4 \7 Q record-data
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;; give the turtles an initial speed3 W0 v) I" p/ D6 ?$ E( u/ {+ l* h
ask turtles [ set-car-speed ]" ?2 j1 _1 y/ S" j. {$ C1 b6 G7 z G
4 N) g1 o- i4 a: [/ e reset-ticks, E! [4 b n: d) e% e) @
end+ m( q+ b" W @* O. @
* t, J4 C, t" h;; Initialize the global variables to appropriate values
* P& o8 v* y& B6 Dto setup-globals
! U( z1 ~6 k" j# G- B0 y set current-light nobody ;; just for now, since there are no lights yet/ g: v M; N! W ^5 N7 v/ e n
set phase 0
9 w& g2 X6 m6 A set num-cars-stopped 0' A; ], @ s8 C" f5 H! ^% Z, k
set grid-x-inc world-width / grid-size-x
( E d+ s5 ~" x, }9 X5 x set grid-y-inc world-height / grid-size-y! \8 u4 z0 I( y- P8 T1 l
9 x% [2 I9 G% E& [8 {2 \& G ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; m" `# j) G8 b# @ set acceleration 0.099
+ F4 O" P$ Z0 F+ v. i2 nend2 E1 N! \' l- K2 J Q8 O7 R+ L
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ e5 x; e; V1 l# `& W0 B) y
;; and initialize the traffic lights to one setting" J, G8 l( ^( h i3 H
to setup-patches" b! Z! t8 r' A4 p
;; initialize the patch-owned variables and color the patches to a base-color8 ]* `$ e& ~' g1 {6 z4 w4 C5 C
ask patches
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" _1 t9 ~0 M/ t; Y9 b2 s3 a4 @ set intersection? false
6 y- U% p% K% ] set auto? false
) i F- e0 }6 K) J, c3 f) X set green-light-up? true
8 `) q( M- H2 w* g0 n6 [4 `# s! X set my-row -1
! l: z3 K1 Q0 Z8 m set my-column -1
( P/ K4 ]2 l- z* I! A* d set my-phase -1
+ e# d5 p+ t5 d set pcolor brown + 38 V$ ?! W, z& u9 F) q
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G' v6 }4 O# V& l: L+ G) A ;; initialize the global variables that hold patch agentsets
! G7 G3 e' D: D# d set roads patches with
$ u1 U8 I. x% \8 }( }. s$ A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 u5 T2 @: ~( V- j- e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 n: d$ L0 n# d) A+ E set intersections roads with
+ K1 Z: }/ R0 ?0 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( }+ Y* I3 g, g! ] ~+ ^. N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- w2 Z2 j5 x1 s) c: C% g' s2 l
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ask roads [ set pcolor white ]
3 ?2 K7 B) B* E1 `* ?8 _- c setup-intersections' t3 i e" j& V5 V9 J) m- `( _
end, K9 b; Z5 l; N4 w9 t
其中定义道路的句子,如下所示,是什么意思啊?
/ e! k. }7 Z8 `: p+ ~ w set roads patches with' H0 Q) _% e. ?# o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
X* @3 ~) s. M D$ B9 M- b, Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 T/ [; K$ z9 p
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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