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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。
! g# m+ S8 R5 [ m2 @netlogo自带的social science--traffic grid这一例子当中,+ j3 e: h& t0 J1 I' G- M) j
globals. \* Y; ~+ J# W$ S8 I: M
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9 ?" \- B! y% `$ m9 Q& V7 R grid-x-inc ;; the amount of patches in between two roads in the x direction4 e, i* u- x) K$ A, y9 ^
grid-y-inc ;; the amount of patches in between two roads in the y direction: q5 d& a' ^! I. u: k+ z0 q# l- C
acceleration ;; the constant that controls how much a car speeds up or slows down by if5 ?; X, p# k! p/ {
;; it is to accelerate or decelerate. ]4 y2 }; P3 H5 {0 ~' _( C
phase ;; keeps track of the phase/ ?- h- M& T ~8 ~& `) Z) L
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 I+ b1 W. I2 @+ G- ], a
current-light ;; the currently selected light& b( ]+ [2 c: k) T7 N0 X6 ]( _
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;; patch agentsets
, r% i8 ^- i/ M9 U intersections ;; agentset containing the patches that are intersections
3 }4 V, F. ~5 y* `" O0 U7 V roads ;; agentset containing the patches that are roads9 h3 w6 F9 I4 J/ E! h& j, T
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turtles-own: A, n) Y7 v1 Q1 }" p3 V
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speed ;; the speed of the turtle
* O2 u6 N. C# Z$ k up-car? ;; true if the turtle moves downwards and false if it moves to the right
, \) r) Y$ a( _: [- C* n5 u4 f wait-time ;; the amount of time since the last time a turtle has moved- y5 R! h: ]; H7 ^, n: |
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patches-own0 K( Z& `! N2 j( y
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intersection? ;; true if the patch is at the intersection of two roads
' N& `$ j2 [; }4 D! B green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ ^6 D! g! T# n6 m7 U ;; false for a non-intersection patches.
4 K, d6 @6 n" u8 e) B: D: y my-row ;; the row of the intersection counting from the upper left corner of the8 }3 a+ U1 z8 `4 X" p
;; world. -1 for non-intersection patches.1 S e& |% a3 L4 L5 k& ~
my-column ;; the column of the intersection counting from the upper left corner of the
5 f7 G4 ^9 y( |: h K: H* ]# Y ] ;; world. -1 for non-intersection patches.
) A+ `! u5 p# E$ |( B5 C% ] my-phase ;; the phase for the intersection. -1 for non-intersection patches.% ]6 A3 W6 M- [: e4 H7 [
auto? ;; whether or not this intersection will switch automatically. W2 B' s' U/ l/ h- ^9 ]6 o! r
;; false for non-intersection patches.
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5 R. m6 R$ e. _! u/ _2 ~' c;;;;;;;;;;;;;;;;;;;;;;1 k' x1 y2 F+ M* l2 p1 `8 x
;; Setup Procedures ;;
# @3 L( j) Q% @) I* ~; l;;;;;;;;;;;;;;;;;;;;;;
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0 u, e: Z5 l, \7 n8 T;; Initialize the display by giving the global and patch variables initial values.! Y3 u* Y* Q/ S$ v4 O# b
;; Create num-cars of turtles if there are enough road patches for one turtle to7 k7 y7 k4 t r3 T. d. N
;; be created per road patch. Set up the plots.
0 T8 d* X* F% fto setup
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2 O& C; x/ W$ ?5 w4 l; T# s& H& I% r setup-globals8 Z+ d5 X- S3 O. q, T
$ R) H. b1 [; Y. w3 r6 u! _# z" X8 m ;; First we ask the patches to draw themselves and set up a few variables
3 n/ O; _) O! V setup-patches1 _# h3 b {' U/ b& d
make-current one-of intersections
& Z; a- V: k- o3 s. K1 S: N% s" { label-current, ^5 i9 [- u7 w1 I9 S* h
& \1 `. ^) q1 U8 W* o7 P set-default-shape turtles "car"( h7 v1 L- @8 I- N0 l: o2 L
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if (num-cars > count roads)6 C! Y/ T( m5 d' t4 j9 A5 \
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user-message (word "There are too many cars for the amount of ") ?6 B/ l$ H3 {( n( c# T2 ]
"road. Either increase the amount of roads "
8 \0 k' B2 E! X5 B1 r "by increasing the GRID-SIZE-X or "
0 h2 t& b: j, t% T/ B5 H. \$ j) L "GRID-SIZE-Y sliders, or decrease the "
% z* J r9 z! m6 A! z5 v "number of cars by lowering the NUMBER slider.\n"
! I4 c. v" Z3 V% ^$ K- |( F "The setup has stopped.")
$ S& b; h7 \6 u stop# s7 K$ O: }. _, V5 `: ~7 e
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 J6 N0 q3 a6 a/ A
crt num-cars
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4 Y: L% h' x$ r3 O' K- g9 O5 M! Z7 i setup-cars
1 t3 R% T8 }9 ^* b% A set-car-color! T0 `6 ?* C2 W' H9 U4 d
record-data, a9 t. C# R# g/ o6 n* z# F
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;; give the turtles an initial speed
# f' _+ m1 Y0 C- E( ]$ S ask turtles [ set-car-speed ]
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reset-ticks
1 \9 [+ K. @: m8 [( `end
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* \3 `3 m9 f O/ A8 M' V& r: }- m;; Initialize the global variables to appropriate values
1 i1 s8 m3 ^/ w& _6 {" tto setup-globals
: d! N1 y4 N5 I* W z' j# {& B: F+ U set current-light nobody ;; just for now, since there are no lights yet
" r' B5 B+ J8 m# F* l& Y* Q set phase 0# K+ N* M9 H- C! Z0 k
set num-cars-stopped 0
0 K6 w0 k- l4 Z% t3 ] set grid-x-inc world-width / grid-size-x
0 f* i( v. V' A& ]8 e set grid-y-inc world-height / grid-size-y
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0 V. y# B: C5 J5 k( w5 T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 o1 A1 j. ]$ G" l- r
set acceleration 0.0993 v- f1 \+ ~1 F4 }9 D
end
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; Y+ i& {1 T- W/ s) o; o;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& ]) L0 r+ I" r1 U: U
;; and initialize the traffic lights to one setting
+ ^8 Q4 T2 r+ X! O1 H# l8 Pto setup-patches
. W3 \% w& I5 t ;; initialize the patch-owned variables and color the patches to a base-color) v! g) f. f) _. i; G9 b+ p
ask patches- }5 o& o5 G: s& P5 b2 O9 m
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9 S! r* A/ `" p: o( w$ R e set intersection? false
3 `2 A3 V+ ~9 r; c- c set auto? false
0 G& v n v. z1 l8 |$ { set green-light-up? true7 A: [. b/ w7 u( \! \. g, p/ Q. s
set my-row -1. t9 V: ?: b) L( G6 L
set my-column -1
v- T' K) [7 }( O, v& _4 K set my-phase -1
- u0 k8 e7 c% b5 J7 L! L6 b/ d% N set pcolor brown + 34 {) |! D7 G0 ~9 P/ s6 u! v
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;; initialize the global variables that hold patch agentsets
|' b% M% H4 j' w6 F set roads patches with$ G- M- [6 x/ v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 {/ c6 T, M/ o9 U2 V" B, D# w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 v @' f9 E" U
set intersections roads with
\; T! k6 u% O+ ^, ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and" M2 m( U3 _! O6 m+ _: \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]7 f; V* w6 K* Z6 @/ |
setup-intersections
+ _" R5 D O6 I5 }- iend
% R* H; F# S0 O8 B) L; D5 r其中定义道路的句子,如下所示,是什么意思啊?
* ^' h* V1 D/ G t4 F4 C0 t% ]( a set roads patches with# ?0 u5 A$ V( _: W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or B3 Y: Y+ q1 a* f( Y/ F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], O# v1 t, `. \; u* ~" Q$ r
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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