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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。" O% b" r' @* e" O' ?& K
netlogo自带的social science--traffic grid这一例子当中,
7 |" g! i& p( j" t0 V4 U6 n+ qglobals
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! w% h. B- n$ f* M1 t! ?9 P grid-x-inc ;; the amount of patches in between two roads in the x direction4 k( l" \; A9 u8 I- w5 T
grid-y-inc ;; the amount of patches in between two roads in the y direction
- h- ?$ p9 c6 `0 Y& s acceleration ;; the constant that controls how much a car speeds up or slows down by if
' S, ~+ t# u+ q3 a4 v$ r" T ;; it is to accelerate or decelerate
$ r& B7 y, f6 g/ t3 U phase ;; keeps track of the phase% ?2 Q; L3 Z0 N- H1 N* S
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" p% w; y& O1 Y% Y c% c
current-light ;; the currently selected light
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( N4 B1 J7 s. O3 f ;; patch agentsets
% K X( ^; D4 g, n2 \ intersections ;; agentset containing the patches that are intersections
& Y8 l$ @# v* _- K7 b2 q: T roads ;; agentset containing the patches that are roads
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turtles-own
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+ j" m8 C5 V r+ |( {, L speed ;; the speed of the turtle
# a6 H r; \# S# {4 ?: ]; B up-car? ;; true if the turtle moves downwards and false if it moves to the right
# {/ {: H- v5 | B wait-time ;; the amount of time since the last time a turtle has moved
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" E+ @) z3 ]. [ G% U- Q: dpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
c+ a/ {/ u% l$ G4 ?* L green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- H) w+ O' a! d5 Z9 B X ;; false for a non-intersection patches.4 }, u. A+ a8 K& Q* S0 B ~$ L
my-row ;; the row of the intersection counting from the upper left corner of the
# R5 x1 l5 K$ L ;; world. -1 for non-intersection patches.5 ~$ W; ~7 S' k8 {! ~3 V; h6 O; _
my-column ;; the column of the intersection counting from the upper left corner of the
3 J! k5 L; P4 ? ;; world. -1 for non-intersection patches.
, v' O6 p% B0 s1 X$ r, M8 m% r7 x my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! h' j3 B4 x+ U8 { auto? ;; whether or not this intersection will switch automatically.% {# W9 ]4 [2 N" a0 L$ u
;; false for non-intersection patches.- }$ q* E3 I( Q: x9 a4 S ?
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6 G: O* R/ ]! e4 s;;;;;;;;;;;;;;;;;;;;;;
$ ]9 _: B6 N' X$ z) n) t1 R7 n6 R; r;; Setup Procedures ;;
! j1 Y1 R S$ B! ^5 h1 i3 Y; v;;;;;;;;;;;;;;;;;;;;;;1 U' Z# v9 L ~7 |& k0 C
" |0 S2 j9 B! ?1 f;; Initialize the display by giving the global and patch variables initial values.
* l ~% x' H% A3 m& C P;; Create num-cars of turtles if there are enough road patches for one turtle to
7 c) j" H3 P5 c+ F;; be created per road patch. Set up the plots.( C8 x3 K2 | k
to setup+ }9 N- {% U- C
ca
! I. q6 I) u5 d' A setup-globals
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. A6 p1 h" E g ;; First we ask the patches to draw themselves and set up a few variables
. I* y1 Y0 a7 D* N: }# H9 Y1 {" t setup-patches
5 L3 M8 K1 f5 [3 g! U4 {) o8 N make-current one-of intersections$ L6 r+ @9 M! R* _
label-current) I' Q* {, j9 l- H0 [# }
/ S5 `5 z3 D- ?! T* b set-default-shape turtles "car"
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- }" D5 T3 P! Y7 {+ E; M if (num-cars > count roads)4 e' Y: u! L9 W5 j6 z, { q
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( \, H7 e( x2 O+ U user-message (word "There are too many cars for the amount of "
) P$ g3 W1 M) K$ O w. [ "road. Either increase the amount of roads "
?/ E9 D) _+ C" Q: U "by increasing the GRID-SIZE-X or "& T7 e t. H9 J. q$ M1 }& S
"GRID-SIZE-Y sliders, or decrease the ". l% |/ t' E; P" q: _
"number of cars by lowering the NUMBER slider.\n"0 Q- P* I7 ~% }! A4 x
"The setup has stopped.")2 Z: J/ z" U4 M0 g
stop
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; A# a4 P& B& L/ b ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# t1 Z2 k6 ~$ E
crt num-cars6 g9 M; \3 h$ b* `
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setup-cars
5 f" e( H9 H. \5 z$ X set-car-color
e* Y$ M7 H$ o+ q record-data
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4 J6 t$ R0 o, @0 ?, x ;; give the turtles an initial speed$ F2 o( f5 Y7 \" E
ask turtles [ set-car-speed ]
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& V! a& o! W* ^! |2 ]& \. ^( Q) P reset-ticks, W) A/ R3 ^7 \$ c0 L- d
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;; Initialize the global variables to appropriate values
! L" ~- r4 }) S1 C& Uto setup-globals
, e1 a, m% B: g, D/ |( |/ Z set current-light nobody ;; just for now, since there are no lights yet2 _3 ~- K. t" F; n
set phase 0* r# I0 I0 f! ^! D
set num-cars-stopped 0
6 a2 @ } }( V" w G set grid-x-inc world-width / grid-size-x" P1 _6 c! w4 K. U2 X
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 N- W6 }* b! t* x
set acceleration 0.099
& G* k" n, @0 W0 Fend
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; W' E( T/ Y6 S+ T% O;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 N4 s6 |) _1 z$ d
;; and initialize the traffic lights to one setting
3 J/ n. d0 |9 N, Y4 D; `# b8 Zto setup-patches; c$ I" ]$ Q$ c- w; C4 l8 o4 i
;; initialize the patch-owned variables and color the patches to a base-color
2 l/ t3 [3 c# {2 R. I5 t. ^& ^ ask patches
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set intersection? false
( R0 m6 D' m- M+ i& B set auto? false
5 C0 n% ], |$ d/ x& O set green-light-up? true
4 h, @% t5 s% y6 ~ ^ set my-row -1
5 G' r8 l/ t2 n/ n# t6 f set my-column -1
6 W. q2 p- X9 C% H4 V* X set my-phase -1' q) S' ^9 a: R% ^3 O
set pcolor brown + 3* }+ V, ] M% ~. ]- x
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( _: p3 h9 E7 l9 c! d ;; initialize the global variables that hold patch agentsets
, j1 ~. J' a2 I' X: k/ j, S) K set roads patches with
( x1 ~: R2 Y" x6 f' O8 ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 i) K" Z0 y' t. n& @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 U- x/ l5 K: H% S2 G set intersections roads with" p% d0 x4 h: }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 q9 U5 \3 U2 c6 d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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! ~" r6 m$ Y# ~; S ask roads [ set pcolor white ]
, |/ z, X2 a1 U! q N X) O setup-intersections
$ Z. z, v' L+ {* c: Uend
0 U Y4 l" u& J- v D' P其中定义道路的句子,如下所示,是什么意思啊?( J1 ^& o* L u
set roads patches with
( t# y$ \1 K9 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) P5 r" L: D* y( n7 c( @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 }0 t* Y& P) M; 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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