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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。6 w- a! c+ L, a; B8 J; ]
netlogo自带的social science--traffic grid这一例子当中,
3 u, Q% l9 w) A. P/ Eglobals0 C! ^* ?$ T7 {1 V
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" ~7 s; e) X5 T F4 w grid-x-inc ;; the amount of patches in between two roads in the x direction% v: T' o5 k6 n2 ?5 N
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 ^. | @/ L% r, m7 o& n acceleration ;; the constant that controls how much a car speeds up or slows down by if
; W' P- n" E9 F. U3 {5 A5 E ;; it is to accelerate or decelerate
+ W* O: z" x3 D" }& T# e, I, q phase ;; keeps track of the phase
( L& t5 y) P+ w V4 L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ Z' t4 o- s; c2 X% O current-light ;; the currently selected light
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5 D! S8 Y$ s$ N( I+ |. t, T6 b, u ;; patch agentsets
* f6 M* m! T# J* D5 D# N' n% v& p intersections ;; agentset containing the patches that are intersections
# T1 y6 `$ v7 P. l roads ;; agentset containing the patches that are roads( ]0 z1 m- D! C$ B* {: S" P
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1 d8 ]' ~) n4 f9 L9 ~5 ] sturtles-own4 \9 ?( h- D# J# z- e+ k- K
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. d0 J0 k; ]8 D% p: r speed ;; the speed of the turtle9 K7 o1 M. @0 ?: e5 ?+ S r2 W
up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ V# C. d) `" \9 I wait-time ;; the amount of time since the last time a turtle has moved: h+ s* `, K, S
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patches-own$ c% G& R; @. m
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intersection? ;; true if the patch is at the intersection of two roads
+ l: i% ?0 g6 W4 q' t green-light-up? ;; true if the green light is above the intersection. otherwise, false.- D" d% F5 v1 p/ [0 L! P1 E4 _
;; false for a non-intersection patches.7 g% ~0 {+ A1 g/ C
my-row ;; the row of the intersection counting from the upper left corner of the
3 O* u7 _5 B8 t, u- s& c t" d' e ;; world. -1 for non-intersection patches.
% V5 t4 z, k8 U$ { my-column ;; the column of the intersection counting from the upper left corner of the
" J- B) B5 _; Y0 e3 |! b3 Q- r ;; world. -1 for non-intersection patches.
; y( [3 c' Z3 Y% {2 Y+ y- {$ } my-phase ;; the phase for the intersection. -1 for non-intersection patches.% |# }. P! |+ \1 m G- V0 v! O& p
auto? ;; whether or not this intersection will switch automatically.
1 G* f5 f% k9 A# A% W ;; false for non-intersection patches.2 V: H! [. C, g+ N6 r1 f
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+ l+ p' ?4 Z6 _4 b# ^: `0 o" r;;;;;;;;;;;;;;;;;;;;;;
/ ~! v4 D( ~) R* u8 s3 F;; Setup Procedures ;;! \; X1 H% L( `
;;;;;;;;;;;;;;;;;;;;;;' K# g7 W" C( v: T- E; A& B
, c+ J% l2 Y _4 M;; Initialize the display by giving the global and patch variables initial values.
( s2 X: k, G% O6 [# q Q;; Create num-cars of turtles if there are enough road patches for one turtle to
?& V% X7 z) ]7 c;; be created per road patch. Set up the plots.5 N: C) n. y3 w
to setup
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" u5 Y" r8 I/ o: |' D2 u setup-globals
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* T7 X x. d6 b j/ z ;; First we ask the patches to draw themselves and set up a few variables6 B( L1 c$ |# Z) l6 m% s* w' w
setup-patches
4 a! S0 ]+ M1 m X+ ~! } make-current one-of intersections
& M, @( n; Z" l6 w0 n label-current
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. g. D7 w& I, v, ?! x5 c! ] set-default-shape turtles "car"
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if (num-cars > count roads)% t, X) W, B( V$ _; f" h+ Z( O
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3 O# l# e. R" R; b user-message (word "There are too many cars for the amount of "
, D2 H: L9 a- v% H* q "road. Either increase the amount of roads "
0 V6 T! i) ]. j, f% u2 s" F/ I "by increasing the GRID-SIZE-X or "& q3 r4 I3 y3 p" m
"GRID-SIZE-Y sliders, or decrease the "
( m) v1 T1 x7 V "number of cars by lowering the NUMBER slider.\n"
( V9 h' Y$ P2 i: U6 t "The setup has stopped.")
( }' o; n! j1 K stop1 P3 ^, K0 g* o' g( S9 n5 ]% X- j
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' D% p& Q8 g( N: ~1 U" \& t0 J ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# e5 O5 m% L( Z& ~* o crt num-cars
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8 \' m+ A+ N, K* t1 K( v setup-cars; h7 K2 `+ ?1 W1 Z
set-car-color
% [, [4 C+ `6 e+ Z' p( Y+ v. L record-data
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;; give the turtles an initial speed
& G W: E4 D0 ]% _, J ask turtles [ set-car-speed ]" Z6 e B6 ^2 ~. i3 E2 @
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reset-ticks
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;; Initialize the global variables to appropriate values, R) a! g: G$ c2 I% C
to setup-globals
3 O; g. y5 |- {! | set current-light nobody ;; just for now, since there are no lights yet# _' g; y ~; y% c/ s: H
set phase 04 F7 S6 {% y5 z
set num-cars-stopped 0
8 d6 W) n/ q f4 v/ e& E8 m set grid-x-inc world-width / grid-size-x7 K) J3 e% [8 g: x; \# S u% n
set grid-y-inc world-height / grid-size-y
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0 R+ Q) o; G( l a- S ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 l f J' m1 z0 f" W. G set acceleration 0.099# d/ H6 z/ D. ?5 y
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' u. s: c* e: X
;; and initialize the traffic lights to one setting
3 R& _8 N0 X) ^* Uto setup-patches5 V! i" H( M3 G
;; initialize the patch-owned variables and color the patches to a base-color
; e2 I5 e2 K+ a9 z1 k1 I% e% X ask patches
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1 a$ G" B/ d" y; @8 v set intersection? false
5 K/ U5 z: n4 a: I/ [ set auto? false
/ z! W$ `9 ?* t) r1 h set green-light-up? true8 j$ _6 ^" Y9 `% _, `" S
set my-row -1/ o/ ~* v' s0 k1 [
set my-column -15 H1 ?$ D$ |2 u# }; L# [
set my-phase -1
4 R- x8 q$ N; x set pcolor brown + 3
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' I2 v# l1 [- J7 z) W$ G7 x$ ]7 s ;; initialize the global variables that hold patch agentsets
* E/ d/ Z1 K, V8 F: i; {0 B7 Q set roads patches with
6 `6 Z3 n4 o; j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or G6 y* A6 c1 K. v/ y; E8 F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 w# b5 T, B8 y$ ^2 {
set intersections roads with7 L) T' z. w" S0 ~! l/ S3 W2 U6 d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' ?) c" s) E$ Q8 n8 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
; e, `3 Y0 _9 f# H' J+ k* V+ I setup-intersections, ?- a: P2 L( `; c8 D7 s
end2 r' R" M1 l7 D) t6 v* y1 k2 o
其中定义道路的句子,如下所示,是什么意思啊?
' D+ H. M0 C$ T6 z0 m Q0 I) D! c set roads patches with6 T3 y3 f8 y& n. _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* [. w. v9 \% B% f& b+ a' v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! J$ _. a* C& q9 X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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