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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。
/ h( j$ }2 {1 ~: D3 z) enetlogo自带的social science--traffic grid这一例子当中,
/ x% n+ I4 m1 X9 Z/ hglobals
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C/ s9 k( I* J% O2 |+ _ grid-x-inc ;; the amount of patches in between two roads in the x direction4 i' Y( F2 ]. C1 k9 M
grid-y-inc ;; the amount of patches in between two roads in the y direction
: Q- m, F) X; ^" H acceleration ;; the constant that controls how much a car speeds up or slows down by if* }% B3 a* z: [- N
;; it is to accelerate or decelerate8 }9 _5 ]* L+ G5 ]7 ^9 A
phase ;; keeps track of the phase+ u! C5 T1 m- D) G" H5 i
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( d6 P0 L( j x current-light ;; the currently selected light& v. `. E6 B! r' d
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;; patch agentsets
3 B1 y$ d" A7 q$ T# a0 S- Q intersections ;; agentset containing the patches that are intersections" g, X6 G9 u P5 X/ x) Z
roads ;; agentset containing the patches that are roads
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turtles-own. s% o9 S0 H9 `: I7 K$ Q: c% u! Q) z9 T
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speed ;; the speed of the turtle5 c3 D. k/ T9 {5 O/ F
up-car? ;; true if the turtle moves downwards and false if it moves to the right& r2 B7 I& }5 q0 D( c
wait-time ;; the amount of time since the last time a turtle has moved" o! f* Z+ X5 v2 h# S' Z! S1 o5 b
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patches-own# _ ]- v+ }4 t" a
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intersection? ;; true if the patch is at the intersection of two roads* b4 X5 Z& y* i' h/ B: {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" M8 h8 ~: \7 x: b2 }: O V ;; false for a non-intersection patches.
1 v/ K) t; ]9 n6 I8 `* U my-row ;; the row of the intersection counting from the upper left corner of the* S' f; u! o- m
;; world. -1 for non-intersection patches.% t7 ~, W7 L1 o) J' J% u% i
my-column ;; the column of the intersection counting from the upper left corner of the
) f/ L* l' [7 J ;; world. -1 for non-intersection patches.
: @% M8 j( p/ a my-phase ;; the phase for the intersection. -1 for non-intersection patches., Y! P3 C2 G3 P# E, j- O
auto? ;; whether or not this intersection will switch automatically.
$ M% E( U% e% e ;; false for non-intersection patches.8 ?7 t. u! J; x6 l" G# m
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( J6 O& c* Q) o( U3 r3 x;;;;;;;;;;;;;;;;;;;;;;
; \ _' l0 i2 x0 {* \;; Setup Procedures ;;" g9 ]' H1 Z: B! j2 p5 T
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.- A O" T7 u$ j( E: P- c
;; Create num-cars of turtles if there are enough road patches for one turtle to
G6 e* s6 Z3 {5 N;; be created per road patch. Set up the plots.% D6 _7 F; |5 C' X% i
to setup, K# }+ q0 v* Q2 V4 z
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setup-globals
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1 C+ x. o* _3 c' n2 ~ ;; First we ask the patches to draw themselves and set up a few variables" [8 R+ k$ A9 k: X. p
setup-patches0 n& H1 Y3 P" Y1 A% s/ Y- t' H% n1 c
make-current one-of intersections" j6 W0 }3 c$ k9 H4 i: c
label-current* t6 G9 b: {$ u7 h9 N9 f
$ M, J" \, l4 c) s' h set-default-shape turtles "car"7 M4 [- U, N% t2 G, P" Z2 S
8 q; i" K" m* z: J ^0 Z( M& \8 ^ if (num-cars > count roads)) Y$ ]) p& e- V, s) K5 P
[
! d) ?4 p# t n% @: s- Q user-message (word "There are too many cars for the amount of "3 k4 V' b+ e# L+ {# b' \
"road. Either increase the amount of roads "
) r2 m1 z4 ^' Z+ H, ]- s+ \- k" ^& e "by increasing the GRID-SIZE-X or "2 h# R Y& j5 C$ r! @8 o9 [/ x9 t
"GRID-SIZE-Y sliders, or decrease the "' i; m! j# t$ g( p
"number of cars by lowering the NUMBER slider.\n"
8 R3 Y' X: O5 `+ j4 l) J7 Z, [ "The setup has stopped.")
. P* K& n/ @1 A1 ~7 F2 [6 F* I6 g- O& J/ G stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: m. V" a; x7 N- J& ~. X
crt num-cars
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setup-cars
y5 b- P0 T8 Q% `' w set-car-color
/ X5 k' H7 H& y) k record-data) K* Q3 S7 i' P) x: \
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;; give the turtles an initial speed
. c% |& l/ {. T ask turtles [ set-car-speed ]
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( z/ z& X& r4 @9 }4 Z' ^/ ^ reset-ticks
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$ j9 t3 U5 H d0 j;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet6 h. F, P- ?8 C& V2 [3 @
set phase 0
1 p$ u; ~6 G( b/ r7 _( A set num-cars-stopped 0
! m. s8 Q. O( G5 l6 I/ J4 O; t& a set grid-x-inc world-width / grid-size-x; G( |- b. T' M! O
set grid-y-inc world-height / grid-size-y: @9 Q+ @* P# G) Z* g
/ u) n+ J+ L! y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
u: i9 |" M; e4 w7 s. ~ set acceleration 0.099
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/ S3 w/ `( Z9 N$ f9 l2 e/ y1 C% S4 k;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# S/ _6 N8 [; m+ G5 L; T4 P8 C3 v;; and initialize the traffic lights to one setting
0 ]. C2 Y6 }* ^: e/ xto setup-patches
' R9 T7 ]: Y# Y& V) C/ ` ;; initialize the patch-owned variables and color the patches to a base-color/ p9 z* `( Y. v5 J' i
ask patches: _6 d0 y5 K* \, y- [/ S d
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0 g" ^8 f) d' h% v1 \ n8 h) ] set intersection? false
5 o6 W: C; a, p: V6 O% m* D set auto? false5 Q, F0 q1 B. ?0 F0 C2 U0 A" c3 `
set green-light-up? true( `8 P' I3 j# l
set my-row -1
# e7 n& C3 L1 x. ]0 \4 v z% q% H set my-column -1/ B9 D% d6 c4 ?9 H3 P+ N
set my-phase -1: p2 T, q2 l+ A/ \7 @5 I
set pcolor brown + 34 }" q0 w. F) z* V7 U5 G3 t
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4 Z2 Q' \9 n$ @) { ;; initialize the global variables that hold patch agentsets' y# |* C5 O0 x- A7 J# m% t5 J
set roads patches with9 g' w& G [# T5 I, t* b) @7 c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 y6 D! J) P- e0 W* e/ a3 O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( q. [2 u/ c2 d9 |# f# r
set intersections roads with
8 Q" r9 s5 S1 E3 y0 {9 P) U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' W# v# K' N) s' q, ~# { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' c: T/ Y. y3 q( F+ j" R1 L' t* V( q
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ask roads [ set pcolor white ]
9 C: K T/ H8 C" ^( E 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?
4 B; y B: w; h) N/ a$ Z set roads patches with
/ M8 u) c8 D8 U2 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 O8 D& [, }& C" c! f5 @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* p7 Z9 G0 ~2 ?0 d% S) f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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