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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。5 M" H5 M1 a! ~* j1 i
netlogo自带的social science--traffic grid这一例子当中,
& u, S* P* ], u! H* R* aglobals: V7 B4 M6 x4 J
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grid-x-inc ;; the amount of patches in between two roads in the x direction
h4 P5 _& [6 _8 B$ k grid-y-inc ;; the amount of patches in between two roads in the y direction
( _4 Y9 g$ {: ]# Y+ d! }, y acceleration ;; the constant that controls how much a car speeds up or slows down by if
* D" j W. [1 c; [" G ;; it is to accelerate or decelerate5 V4 B" t; h" k
phase ;; keeps track of the phase
: t$ {3 T$ j& s- o0 r num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 n' e" H1 U1 x
current-light ;; the currently selected light7 H M! \3 `3 z) v2 L6 j6 S. Y
z7 I, z$ f; n2 g: ]# q ;; patch agentsets
( ^/ K3 s7 d% t. y3 f2 Z intersections ;; agentset containing the patches that are intersections
* i. z( v0 I d) k- L2 e S roads ;; agentset containing the patches that are roads
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turtles-own
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# V" I! \0 j9 E. s3 N7 K speed ;; the speed of the turtle0 m y6 R4 s9 M% g: A
up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 O) b6 z3 `. E+ l" v' X+ | wait-time ;; the amount of time since the last time a turtle has moved, Q. k' w) w; G) v- O% c7 E, K3 `( z
]
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patches-own5 g4 F& u+ A* c4 a h6 n5 x, j
[
v9 m4 m) }% r intersection? ;; true if the patch is at the intersection of two roads5 i0 ?' G; p$ {) I- m# Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 T5 ]. H( u+ h! G0 {1 f. L
;; false for a non-intersection patches.
: V4 }3 z3 u2 l+ {+ R8 C' v my-row ;; the row of the intersection counting from the upper left corner of the
& ]- i. D4 Z- H: o, |' L ;; world. -1 for non-intersection patches.
" m9 M% u1 I: ~) `" D my-column ;; the column of the intersection counting from the upper left corner of the
' e5 C; y0 N' Q+ C; E* l ;; world. -1 for non-intersection patches.$ h3 g' V* ?# }
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ R9 v% m/ A0 e* C
auto? ;; whether or not this intersection will switch automatically.3 P/ W& v4 o, Q! U9 y& F
;; false for non-intersection patches.
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2 ^2 L/ O6 F' P- R& ^' N;;;;;;;;;;;;;;;;;;;;;;9 Q9 d, z- e' Q) ]4 L( ^% b
;; Setup Procedures ;;' c0 e* E2 K# ], k
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;; Initialize the display by giving the global and patch variables initial values.
# C* y/ j3 G/ _( k% E& ^;; Create num-cars of turtles if there are enough road patches for one turtle to4 D3 b/ K& L) A* k/ D$ O
;; be created per road patch. Set up the plots.
8 M" x7 f. j+ @5 D9 [0 ito setup
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setup-globals
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! R* F: Z3 s+ K" ~9 g/ z4 g4 } ;; First we ask the patches to draw themselves and set up a few variables; J5 [( H' M0 A9 v" q& ]
setup-patches
' {7 u6 [/ t$ l% B- q1 r make-current one-of intersections3 `6 Z1 K* d3 V R& M% V) W
label-current
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$ _0 ~& G5 Y2 [% z set-default-shape turtles "car") {8 w/ @6 Y. K! ?# A
5 ], z: O8 H: {# B7 N# l! f+ ` if (num-cars > count roads)7 |3 C9 W: i" E
[
- x- h- S; g: ~' h& E: L user-message (word "There are too many cars for the amount of "
+ R" o/ t! |! S6 t) s$ n& N" y$ f "road. Either increase the amount of roads " Q* e9 i( X( P v# }" x
"by increasing the GRID-SIZE-X or "
4 _( d ?. C1 h5 x+ A "GRID-SIZE-Y sliders, or decrease the "% [1 H- r+ u$ g, x
"number of cars by lowering the NUMBER slider.\n" J. v/ r U3 u, a" p: `" V2 i
"The setup has stopped.")/ k2 k4 D ~( h$ i4 }$ k$ F- `
stop
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0 k8 e# p1 |. o ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 m4 j( `5 d ~- _* }; H crt num-cars
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setup-cars
, B/ p8 y! J% w q. f, H6 t Y set-car-color8 G$ ^* X% x+ z6 @( y5 {; i$ M' F
record-data1 G9 B/ L/ z& r! n! D0 W5 l
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9 S) E6 C, {% C4 t4 k3 R& N) y ;; give the turtles an initial speed
3 ?7 U) ]$ S! ~" E, `3 m ask turtles [ set-car-speed ]
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1 A3 w7 J8 @. Z3 o reset-ticks# e- O1 p. A9 D! [- Y( b: t P! G
end
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;; Initialize the global variables to appropriate values: A D2 g0 q! o7 E
to setup-globals
1 Z/ S' G4 ~6 D( _& x set current-light nobody ;; just for now, since there are no lights yet
( q' F Z* A, T9 J- y9 a: @2 w set phase 0
& h" b2 B' r4 y7 v3 M* C- d set num-cars-stopped 0
2 F& p- F/ O; s; E2 r set grid-x-inc world-width / grid-size-x
/ i6 U: J0 ?& m3 y set grid-y-inc world-height / grid-size-y# y6 R* V k- j
! N! P4 \& l0 ~/ Y1 f9 ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) |7 N4 ^' i+ k; k+ m set acceleration 0.099
& I3 r* g8 l) cend
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! v2 n2 p: W+ u& I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, c2 j- }: i0 Z8 G: E6 Z;; and initialize the traffic lights to one setting: Q8 R8 s2 p, l4 v! @ G
to setup-patches
8 Q0 d1 |, x+ i B6 p ;; initialize the patch-owned variables and color the patches to a base-color
0 F3 S* Y# c* ]. n) U ask patches) U X: s9 s- W
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set intersection? false
5 C. y ^+ H; Q" T5 d% k6 J5 r set auto? false! l0 }7 m5 ~$ T/ ]# n {+ I
set green-light-up? true
. H4 T6 f5 } X# W# Y4 Q: \ {# P set my-row -1# G6 t- u9 h- i# a& h C# B/ i
set my-column -1
$ e3 \" A+ \$ Z( C set my-phase -1
( u- M y- h/ @0 C- e set pcolor brown + 3: E8 K5 k& P" s& S
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+ r9 k" G! g# r ;; initialize the global variables that hold patch agentsets& T, S0 C1 C) y" ^
set roads patches with: j9 o% o3 v" f; H O4 ?9 }2 @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; A+ L! L+ I7 ^7 o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: X. I5 T; u3 Q I set intersections roads with o( k# S9 j. d+ O' F4 g7 d/ ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. F& c& Y! i- U% m% H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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2 [6 Q1 ?& }( I+ [ ask roads [ set pcolor white ]0 w5 g, p! l9 f: c
setup-intersections
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y4 |8 X% U, p7 x! @其中定义道路的句子,如下所示,是什么意思啊?$ ^8 P0 p' K6 L8 w, z& H
set roads patches with
" ?8 s0 m2 ~: i" x4 R' K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% W1 U* W0 K1 M2 T# ]( Z5 p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! J3 y; S( W4 b( ~ [' 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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