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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。) ?# |: `" R% |, A$ W; w# f+ [) [. x
netlogo自带的social science--traffic grid这一例子当中,9 `9 H2 W3 f! [) B! R
globals5 G) a( j$ |7 d5 M6 Y
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grid-x-inc ;; the amount of patches in between two roads in the x direction
' c2 E. F/ V: O4 p P8 _ grid-y-inc ;; the amount of patches in between two roads in the y direction/ `0 @6 {, y9 P4 m9 Y
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 U$ [1 D* S* d0 | ;; it is to accelerate or decelerate+ E0 E( t0 L w# U
phase ;; keeps track of the phase
0 L! v9 U( v3 ?; t num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. C& `3 h, R' F+ k/ J5 H current-light ;; the currently selected light
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- X' _3 u& Y' t5 \ ;; patch agentsets8 y2 C9 ]7 W) E X
intersections ;; agentset containing the patches that are intersections- ?' a- K: M' W% x! M( \' c+ d( G' y# j
roads ;; agentset containing the patches that are roads, M) ~% {# J0 L, D" g1 s7 J1 m
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turtles-own+ ]: r; v! z' I$ |0 O; i) i
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speed ;; the speed of the turtle6 x5 |; L4 J% K
up-car? ;; true if the turtle moves downwards and false if it moves to the right
9 S# \3 b1 K) R' l, X, ]4 j* n wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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8 S6 ^- O& y0 U9 h+ g+ [* i# V intersection? ;; true if the patch is at the intersection of two roads
1 C; v0 j+ |+ }, [$ @; T8 i/ S8 z green-light-up? ;; true if the green light is above the intersection. otherwise, false.# b4 Y/ K4 [: ~* t0 F8 S
;; false for a non-intersection patches.
x, w. z# F0 _' M* @8 b# s8 X my-row ;; the row of the intersection counting from the upper left corner of the
" [" }. N# n0 c$ Q. E ;; world. -1 for non-intersection patches.
% J3 C' m+ o! j) R* _# a& ~! w my-column ;; the column of the intersection counting from the upper left corner of the
3 a- ~7 K7 s* ^! y' ]- g$ f ;; world. -1 for non-intersection patches.1 ~* |3 t2 C; ^ T7 W& [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( V# r6 ~3 K$ p. c6 J' ~3 f( d auto? ;; whether or not this intersection will switch automatically.' [' J) O7 R7 @' l/ [. a" a, g
;; false for non-intersection patches.3 q" @. e, K. v! S, Y$ A# @
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% \; W4 l1 l* A' R- j8 [- S' I8 t1 m5 X9 o; R8 r, b% l) h
/ K( u$ C3 J. i) u( Y& _& c; [6 w;;;;;;;;;;;;;;;;;;;;;;: V1 y' M! I3 N: U. R6 ~
;; Setup Procedures ;;
. r9 V$ J" r/ }& Y: l- V9 J: D;;;;;;;;;;;;;;;;;;;;;;! [. |; } `9 t. P
7 o$ W! J8 M' \6 Y' y8 `) H;; Initialize the display by giving the global and patch variables initial values.- F8 T7 g2 y+ z9 [$ J
;; Create num-cars of turtles if there are enough road patches for one turtle to
; _2 g3 ?$ r; @9 Z;; be created per road patch. Set up the plots.6 o* D |4 p3 o- ~% s" h
to setup% e" C6 s4 N. J; n+ e2 j/ X: S5 h
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 R3 p2 v# ~, r% ^" F. _7 F9 f
setup-patches
1 c# E3 K; m# _& F$ x9 R) w make-current one-of intersections
0 ~8 ?) Z% I8 G9 A label-current: @3 k4 C" R8 e& O; [1 ?
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set-default-shape turtles "car"& R m. m. A- e3 d. a5 f
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if (num-cars > count roads)
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# g8 d. D) ?8 |3 {4 j- F user-message (word "There are too many cars for the amount of "% I W, o; e0 L5 u
"road. Either increase the amount of roads "
' l* v" ~0 `/ T# Q+ _ "by increasing the GRID-SIZE-X or ": c9 b6 B6 ]2 ^
"GRID-SIZE-Y sliders, or decrease the "
6 `4 V4 m+ ^& S$ W$ K: } "number of cars by lowering the NUMBER slider.\n"$ `) q4 q4 M2 n; |) [: Z# T" l
"The setup has stopped.")6 B" c1 H# d4 O4 R4 P3 k" f7 F
stop) _& P3 r- V& U7 w( B
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% s# m( I8 `; s% L ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: S: z9 E& H0 K: e0 M0 ~- f" @) |* T
crt num-cars1 A- ~( p, v% {( J. _- D L
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setup-cars3 Z9 e" u, v, n* z# h
set-car-color
6 X( q( I1 J6 p7 X) @. j record-data1 d( C$ I& [1 O: T" W; q& C
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; t9 `/ x$ n% y ;; give the turtles an initial speed
_6 T- F7 D3 j ask turtles [ set-car-speed ]
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reset-ticks9 {) Y& ~/ |7 K5 z/ T' v% d' h5 i
end
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: n6 e3 v+ y) d& I( Q# y9 R3 h* Y;; Initialize the global variables to appropriate values7 T$ r4 |# @) L
to setup-globals$ b$ t4 Q, I5 i% ?4 W8 z: j2 O! u7 \( e
set current-light nobody ;; just for now, since there are no lights yet$ D% D- q1 X# P# \$ x
set phase 0
9 g7 O, V& P! \' \ set num-cars-stopped 0
' W) {7 E' q# I3 D: p: {$ W b9 Y set grid-x-inc world-width / grid-size-x
5 B. Q/ o! @1 K. s6 Z set grid-y-inc world-height / grid-size-y. `3 F/ L" |5 N* N6 F
2 s+ D. L$ i. ^$ ~: u ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" m( J& d6 n* K set acceleration 0.099/ ]9 J! ]- R4 _! B% u
end9 o3 W; Z/ w5 _, A3 M2 o
+ ~( C E9 a7 D( v1 W) F* };; Make the patches have appropriate colors, set up the roads and intersections agentsets," g' O+ ?3 A, S+ B: l* I5 k
;; and initialize the traffic lights to one setting
7 d. [% E2 C/ i2 W" E8 ?; Rto setup-patches! v- m$ I& E0 s E$ J7 j
;; initialize the patch-owned variables and color the patches to a base-color) W2 H7 K, E3 K1 e( q# ^$ H: l
ask patches
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) D- J; l8 \" P set intersection? false6 z" z- y) [' m' V& F3 Y
set auto? false
8 E8 o k a0 h set green-light-up? true" ^! ?9 Z; U( B% O
set my-row -1, z& u* [8 ?, [% t+ r' P) N4 ~
set my-column -1# r/ Z, T3 G2 |# W- p& H
set my-phase -1
. A) L# R+ I5 S5 h* s5 Y set pcolor brown + 3+ @, A2 H- o+ p: D9 N h3 z
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;; initialize the global variables that hold patch agentsets
$ \5 p& x* G5 R- B5 F; j& h, W5 F set roads patches with+ h; k7 U$ [: x b! X \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; E: n; g7 K6 k$ o1 j F$ m: C) g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& c. P+ N! J Y
set intersections roads with \$ V: s9 u( t4 X0 b# ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' }2 X- z: D+ b5 E( I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( l" J* T3 D: d F( l) Q. m3 T
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ask roads [ set pcolor white ]
* u: X0 l5 O* y5 {: u setup-intersections
6 b0 d) Q3 x( k8 Xend
1 m9 H% H) a- W% s$ R/ k7 g其中定义道路的句子,如下所示,是什么意思啊?
# @" ^* U% N) _5 u2 i4 @, ^ set roads patches with
; h; N8 p9 E( Z( W/ H' }" E4 b' ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: C% r2 u, N( O, ]. f% v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ M' W% r$ N7 I ]+ w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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