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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。1 u r: \& q* M6 X$ H/ W
netlogo自带的social science--traffic grid这一例子当中,0 R2 M. p/ `0 Q; g4 }% z. m
globals2 b: A5 K( j# K7 g5 g0 P2 o3 F
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grid-x-inc ;; the amount of patches in between two roads in the x direction. W7 d: L( a5 S- f/ M8 a
grid-y-inc ;; the amount of patches in between two roads in the y direction$ B ]1 c$ {- d5 @5 a4 d7 U/ Q
acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 B" O4 K }8 |& x ;; it is to accelerate or decelerate9 n. Z1 M4 H/ X+ |6 R
phase ;; keeps track of the phase. b. s6 m& q" R) `. S- s( _
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 U* t) o$ E1 ?, H8 y
current-light ;; the currently selected light5 z' ?* X' X, v* c
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;; patch agentsets) k0 P' c; b( V( O% U; N# U
intersections ;; agentset containing the patches that are intersections% l% r m9 D2 U$ Y. l
roads ;; agentset containing the patches that are roads
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turtles-own
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2 C2 y5 I7 `" S) r speed ;; the speed of the turtle
: v4 O( }& v/ Q$ f$ K( ]8 } up-car? ;; true if the turtle moves downwards and false if it moves to the right- ` H" | z: \' H/ [# B
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
t! }3 `5 y0 X' y$ ? green-light-up? ;; true if the green light is above the intersection. otherwise, false.- t3 ?! c# V! m
;; false for a non-intersection patches.
- H3 I. S# O$ Y+ c g9 Z% q) a my-row ;; the row of the intersection counting from the upper left corner of the- L+ @% A7 t0 x& }9 J3 s F& o
;; world. -1 for non-intersection patches.7 ^0 Z% E& H- O1 g+ N
my-column ;; the column of the intersection counting from the upper left corner of the6 Z* i" i( K$ t6 P. N
;; world. -1 for non-intersection patches., D$ T7 {3 C1 r5 o3 c" c5 I$ N
my-phase ;; the phase for the intersection. -1 for non-intersection patches." t" v* F1 [* C+ t& \$ P" J
auto? ;; whether or not this intersection will switch automatically.1 w5 U4 [' }0 `; [
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
4 J# k# y+ m8 N' {- d" `3 y;; Setup Procedures ;;
& @, V' k6 u" B" j6 I6 v4 h1 S;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
- s5 a3 b6 e7 j- L;; Create num-cars of turtles if there are enough road patches for one turtle to9 ~9 X4 ]5 K# ~- ~ d4 N
;; be created per road patch. Set up the plots.
% G2 _8 K' H9 \# Gto setup
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setup-globals4 G: ~$ m5 m) e0 K1 V( a5 i& q
- ^! V+ R& ~- N3 M* e ;; First we ask the patches to draw themselves and set up a few variables# z+ K2 x3 U/ Y
setup-patches" E0 G6 _* ]) f4 Z7 G& `% m
make-current one-of intersections4 g7 C4 J3 I4 \" D
label-current
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set-default-shape turtles "car"
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c) t& T4 C% c2 I6 A if (num-cars > count roads)) J- Y0 A( b8 W$ u% S: }7 D3 q8 ^6 H
[
6 J- v# F5 f+ R9 V7 z" M$ x8 L user-message (word "There are too many cars for the amount of "
6 E% C' `8 Z8 q* o8 J' H "road. Either increase the amount of roads "5 R0 C" ], O' u! \4 U$ [
"by increasing the GRID-SIZE-X or " q7 f# p/ p0 W+ M* b" Q* d
"GRID-SIZE-Y sliders, or decrease the ": w1 w+ U7 p+ J" g g' n
"number of cars by lowering the NUMBER slider.\n"
' E9 d1 W' y8 @7 S "The setup has stopped.")
$ h: X9 i1 @1 l stop; W+ w; B# q- Y ~! E% J- G# F
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6 g9 t2 x( t# Z# f0 Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 x' i0 R- e3 R! }2 m8 r% ~
crt num-cars6 }# l& V" {& k# z2 r5 E- y
[
9 I0 N4 I4 g* U3 _ setup-cars* Y3 V/ a- r' i/ B, W
set-car-color
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;; give the turtles an initial speed
/ K5 t/ x* d, H& G' e ask turtles [ set-car-speed ]+ \( g: H$ n: q
4 O. G, n# S" J3 X" y; L reset-ticks8 M9 k" K9 {/ u6 S0 [
end$ ?! w |3 }: T* j
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet/ Q$ {# C# y u( i
set phase 05 z7 Y7 ]) J* _$ p3 c3 \' h
set num-cars-stopped 0+ T* o; s! Q! {9 P! o1 X
set grid-x-inc world-width / grid-size-x) Y6 T' @5 }7 }% y$ a
set grid-y-inc world-height / grid-size-y
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! G8 K: B* X. R2 J; K4 k, ]3 D; _/ \, F ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, }3 g+ U' h& P$ B
set acceleration 0.099 k1 m h1 q0 F$ ^ U% }
end
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. K$ b- @" H. j- w1 W;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 c, d5 J& |! @1 e$ V! F3 q: d;; and initialize the traffic lights to one setting
! D! m0 U% _& c* wto setup-patches2 @/ c \+ g* @6 x6 O+ Q) r
;; initialize the patch-owned variables and color the patches to a base-color
) ^; f, U6 L8 j' R4 c ask patches$ L& f+ j9 G4 ?+ f
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" ?: X- b% T; p$ A; C9 H set intersection? false( j! Y7 M' N; V2 m. _7 t9 z% i
set auto? false, K! X, i% H' d
set green-light-up? true8 K* x' g: \) \, H( W7 h
set my-row -1
: Y) p4 L9 X' W3 X set my-column -18 @" ~) ~6 ?5 X
set my-phase -1) s7 K8 D: D1 D" z
set pcolor brown + 36 o# E( v7 B+ Y$ p) @: M1 V( A8 g- l
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;; initialize the global variables that hold patch agentsets
+ A& F( Y$ D a2 j X. N: q set roads patches with
7 n; x( ]0 s8 `' W; z, c% O5 ]+ V- u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* E+ g! i& @. K. }) S& K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 R1 Y0 c1 `% b' m( U. R+ t( ]4 U2 f set intersections roads with
* y# n- K7 \+ w) A8 b5 y7 q6 r; q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) \2 w4 B5 K. R7 L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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3 X% v1 T6 ~% e5 D4 z0 V0 @- | ask roads [ set pcolor white ]
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end
0 `; L# H' K! l+ U" N. a其中定义道路的句子,如下所示,是什么意思啊?
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[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- ^5 `, K. p; O0 {$ U. m9 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ T6 ]7 i8 Y6 x! h, C1 g; S
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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