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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。
0 `. U; [; G$ ?0 Knetlogo自带的social science--traffic grid这一例子当中,
3 U5 @9 D% ^% N) V2 D2 _globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 A4 |6 y2 l1 k& P4 g
grid-y-inc ;; the amount of patches in between two roads in the y direction
/ p K8 _& a, u# a* o acceleration ;; the constant that controls how much a car speeds up or slows down by if' Y6 P8 c6 d/ z4 K- m2 S. c! p% g
;; it is to accelerate or decelerate2 O5 O B$ _* f6 I; e- r- w4 l* K Q
phase ;; keeps track of the phase0 ^4 p, Z/ e) F9 v3 k. J6 h7 o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, e" G1 g- h0 j current-light ;; the currently selected light
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# s% Q/ S& n3 i B ;; patch agentsets( N, |* {0 L1 v! ~
intersections ;; agentset containing the patches that are intersections3 e$ K) k0 j4 j' S
roads ;; agentset containing the patches that are roads! b0 w4 w: f( W
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turtles-own
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`# X+ |& P* Z% j/ F4 D: i speed ;; the speed of the turtle- Q% i3 j) Z _
up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ v% A/ w7 q5 L- P- a. r wait-time ;; the amount of time since the last time a turtle has moved
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, @$ a3 A3 b& g' d$ i xpatches-own9 X! `, L1 Q9 u- j
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intersection? ;; true if the patch is at the intersection of two roads. _7 T, y" ?! Y! f
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 d B9 c S, u5 T `8 R ;; false for a non-intersection patches.( ]3 Y: K. e5 y/ C8 N3 n
my-row ;; the row of the intersection counting from the upper left corner of the+ ]* t1 a$ f5 ?# l- a5 e0 l
;; world. -1 for non-intersection patches.8 D4 ?% u7 z! y+ {& |7 ?4 u
my-column ;; the column of the intersection counting from the upper left corner of the
$ A& o/ l ^# N) U ;; world. -1 for non-intersection patches.
2 a( S; ] [. { my-phase ;; the phase for the intersection. -1 for non-intersection patches.. ?1 w3 D) q/ j2 F$ r5 b: m% n
auto? ;; whether or not this intersection will switch automatically.
. B; ?3 Q/ u4 {* P& {, I/ z ;; false for non-intersection patches." F6 H8 A& h. e* \* d" u3 n2 V
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;;;;;;;;;;;;;;;;;;;;;;
) k$ @0 M3 B1 R" B f;; Setup Procedures ;;- D1 c& D" g5 U% B$ W1 x2 Y& z
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
; e/ H0 `0 e* Y4 u3 M2 e4 _) y;; Create num-cars of turtles if there are enough road patches for one turtle to
% u/ N' r6 E8 r) y9 Q( L3 \5 e0 z;; be created per road patch. Set up the plots.+ W" l# ~) Q7 h6 x
to setup
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setup-globals- [5 ~- O# J$ g" X
" P$ `3 w6 [) P& A3 X7 Q S& ~ ;; First we ask the patches to draw themselves and set up a few variables
. c' I0 V6 c( q; t# L setup-patches
/ c) x0 O5 F6 H* F; ]' m3 u make-current one-of intersections0 }. `) I, z" O' }, L$ E7 C% b7 N
label-current
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0 Y" G5 F% m( b set-default-shape turtles "car", F6 J' H# Z* n5 s7 z3 f4 i3 C
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if (num-cars > count roads): Q) a* H( E7 J: j& q* B ?
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user-message (word "There are too many cars for the amount of "
s l: l' W8 e$ F5 L "road. Either increase the amount of roads "
8 C5 }- h% U' l9 Q7 Z( l$ y4 M "by increasing the GRID-SIZE-X or "7 M% c8 U$ ?4 J7 ^# K7 n
"GRID-SIZE-Y sliders, or decrease the "6 k& X' V# R2 A! l* G# c% l% q
"number of cars by lowering the NUMBER slider.\n"
M* T: |6 }- f. F "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-color
$ I _% E4 T" o3 C/ N; Z. | crt num-cars" e7 r- C# U# P) u* n b
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setup-cars
3 n e6 ?4 p2 H set-car-color- f+ K9 B, B% U, W4 j
record-data4 y3 p' L) j& H/ _7 c3 S
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;; give the turtles an initial speed" | n* {9 A7 ^- F5 A2 G6 \# z
ask turtles [ set-car-speed ]9 s5 M! C7 @3 K* v1 w8 h. l4 T
# i' z6 j6 q( k9 Q4 s' s reset-ticks8 s f# L5 ?: d- ?. C0 Y
end
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;; Initialize the global variables to appropriate values
$ i/ u" e6 j3 }- O! Oto setup-globals
0 [* L. k' O+ Y( _9 c8 p& K set current-light nobody ;; just for now, since there are no lights yet
) B# u! F8 L- v. ~8 g1 c2 `" f: y set phase 0
" W/ Y: T4 r9 \$ |, m+ q& V set num-cars-stopped 0% K( B. m; A! f3 k$ i9 L
set grid-x-inc world-width / grid-size-x( i3 ~8 M$ H% g& q
set grid-y-inc world-height / grid-size-y
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" e- A" x: h4 R8 v4 T# u' }. q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 Y% T3 K) ^. o! s+ P2 }
set acceleration 0.099
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2 j( k' Q' q1 }; l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 j8 X$ k" w0 F6 Q8 {3 o
;; and initialize the traffic lights to one setting( A. w8 r9 }* ]8 E& K1 p5 X
to setup-patches
0 @' i1 ^# x- N, H0 X4 t, i) r ;; initialize the patch-owned variables and color the patches to a base-color
. k3 E# @% K% F ask patches
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1 A- [! o* D: D9 \ set intersection? false
) b. }+ u! \& [7 f: m: z) C% V set auto? false
/ o5 U1 G( H8 f/ q set green-light-up? true, |" _' ~5 Z* _, E4 j
set my-row -1/ N. [# ]4 A4 `) Y; F, Z! i
set my-column -1
2 \: Q; T# x: |6 a- U( q: G3 K set my-phase -1
9 X5 F+ n( n# ~# W# x, q( L set pcolor brown + 3
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9 w* J" p7 A' y1 n ^ ;; initialize the global variables that hold patch agentsets
' q% i3 p7 | ^7 A, o D set roads patches with
# [! N$ R4 l; t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# Y* A6 p0 S% N0 J" y9 B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( E0 b& i% h9 L& ?; _/ m4 S
set intersections roads with( H; ?2 ?' D, A# p, {) o! {2 N( X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ G( k9 F/ z% }* u+ E, b9 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 |$ j5 U& H* [5 Z+ ]. y
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?8 x" x( Q) {. i2 v/ t* u* J: A
set roads patches with
( _9 v9 {1 i# v `; |% ~: a' { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! \) S9 ?# ?/ A7 z! }" j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ }% G; v6 N$ P# {: w: z) F" z% U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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