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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。, \' M0 f# n8 j8 R) |
netlogo自带的social science--traffic grid这一例子当中,
+ S( r4 y8 M" P6 ]% Oglobals, |" v5 k, C! e8 d3 n* ?& y
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8 A5 w8 Z' @' y% g- C grid-x-inc ;; the amount of patches in between two roads in the x direction9 ]6 |3 V+ m2 @( g
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 ~7 G! G8 Q6 b# R acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 e6 K" ~+ {7 m/ ]7 @ ;; it is to accelerate or decelerate4 Y1 L- S8 ]% a0 n! M4 k1 w
phase ;; keeps track of the phase
1 y% M6 t" n' x/ [1 ]" \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 d5 L0 K8 B3 T, Q( Y2 T
current-light ;; the currently selected light
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;; patch agentsets
* \% r" m1 }! W8 I, _9 F intersections ;; agentset containing the patches that are intersections; v2 p @2 _ c. I
roads ;; agentset containing the patches that are roads! S1 B5 R5 Q0 K% V5 _
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turtles-own
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speed ;; the speed of the turtle" R$ [( k6 p2 k
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 J6 H) h. d& I# g" Y
wait-time ;; the amount of time since the last time a turtle has moved1 F* x7 B, J# G8 c8 U
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patches-own, o6 w; E8 a7 d! W# ^+ H) s
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intersection? ;; true if the patch is at the intersection of two roads
2 ~ n" l( L2 y/ c green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- q0 h% g0 X7 g- ^3 ^7 k; R ;; false for a non-intersection patches.$ i+ t8 K1 z* T% @# z7 P. D& A9 [
my-row ;; the row of the intersection counting from the upper left corner of the
% Y ]1 D6 K; p1 G4 a% r: r3 s# U ;; world. -1 for non-intersection patches.0 x7 C1 Y0 M8 G4 W: P
my-column ;; the column of the intersection counting from the upper left corner of the
1 h8 u% G/ p! E# C) f- o& i ;; world. -1 for non-intersection patches.+ b- I& Q# X- [' \/ A u1 O! F# V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 F0 y5 `' P# Y" J; @ auto? ;; whether or not this intersection will switch automatically.
, ^4 g6 D+ F4 R% o ;; false for non-intersection patches.. D$ R6 O0 o* b/ s8 H# M8 C; a$ J
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; ~$ Y; y8 P6 T/ \9 A5 f;;;;;;;;;;;;;;;;;;;;;;: M. R1 h) v1 j: g( I
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
% M" b9 x* x5 a7 _# M;; Create num-cars of turtles if there are enough road patches for one turtle to% C' h b, q5 a
;; be created per road patch. Set up the plots. Z' T+ V0 g" h3 \5 {. l& ~
to setup3 I, T" d1 X( G5 {: ]
ca
8 r& |# {5 z4 i% B' J2 O setup-globals
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8 G5 b, N( B1 p ;; First we ask the patches to draw themselves and set up a few variables+ \ j) k& a6 x1 r6 n
setup-patches" H7 b# f- p% F( P/ ^
make-current one-of intersections* o+ Q& Y+ q- t8 h2 y' }
label-current1 D9 i8 Q4 |3 r# i
2 S' M6 v& j Q! [9 q set-default-shape turtles "car"
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$ Q a& ^- Q7 v9 Y; {4 F# R if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "5 w! Q- S+ U% \5 t( y) Z
"road. Either increase the amount of roads "5 D3 |$ D- g( v0 i4 S. y u
"by increasing the GRID-SIZE-X or "
' R6 u5 ^7 ~+ F3 Q "GRID-SIZE-Y sliders, or decrease the "/ x- e* s/ Q0 v) b: b5 D
"number of cars by lowering the NUMBER slider.\n"
- @* U# X) n( u. ? "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& C$ D( m5 T; f2 y1 d# e* f$ f
crt num-cars
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set-car-color3 }. A" ~0 a7 U- U4 \' `* X8 k
record-data9 Z7 P; a- B* Y7 U2 \! \) q
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;; give the turtles an initial speed
* X) x7 p: C& H) e$ C ask turtles [ set-car-speed ]4 ]3 V2 d5 d1 R
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reset-ticks; k! O+ }) R; g0 \3 A9 G( s
end
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;; Initialize the global variables to appropriate values
& X% R$ i X# ]1 Lto setup-globals
4 y) e2 s/ n, U. w2 V$ Y7 m8 R set current-light nobody ;; just for now, since there are no lights yet; r1 [$ S2 E1 d; s4 \8 T% Z
set phase 06 Q- F. o; z+ q' R! E# A1 a* h
set num-cars-stopped 0( Q) ]' L* H1 k, _% g
set grid-x-inc world-width / grid-size-x
2 u7 _) y/ b" i0 q set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, h+ i: h% j4 W8 |
set acceleration 0.099+ @+ j+ s6 J0 L4 j! N5 e# |; g
end% k- ~( m+ D# W7 n: O" e% a5 V" R& P
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 f& O( V" t5 r7 {$ [8 t
;; and initialize the traffic lights to one setting7 r% ?" W/ L4 }# M" |# F
to setup-patches
0 e' n8 @& n* b! D ;; initialize the patch-owned variables and color the patches to a base-color
9 S1 @, S6 j& `8 s% C ask patches
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! `3 M' u& x4 @# p4 O$ G set intersection? false6 @& z5 X8 @+ F3 A- x! o2 g% C
set auto? false! C, |& M5 c [/ y0 }
set green-light-up? true/ ^, _7 d9 O6 Q8 c1 ~' ]" I
set my-row -1
$ e3 u( Q j7 c0 e" W set my-column -19 i6 s! z+ ?1 e$ J$ S* b* [
set my-phase -1
8 w+ d4 i B& O: s set pcolor brown + 3
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3 G @6 }9 a' p ;; initialize the global variables that hold patch agentsets& W _- y5 v! B" Q( h0 S' c9 B5 J
set roads patches with9 \. I6 ` M% `3 r: ~7 n* Q) c/ W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( F: Q% H$ |: k3 j, M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& p$ L/ h0 \) d$ `! V& }: \ set intersections roads with; s3 c6 C" H. U5 G" o3 v4 k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ M* J; y- b- d& s) x2 \5 K+ c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]: y2 S4 i, o( F% l O' \* M
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?
a. U( T N+ n3 } set roads patches with
9 ^! d2 S' A/ g3 a4 ]( X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# J7 l9 m6 g. ~, ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( E2 f4 o3 p) V- i( g. k8 O
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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