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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。
z7 G2 j( M+ |1 S; p5 dnetlogo自带的social science--traffic grid这一例子当中,; h- l) u+ }1 r9 D3 z
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! ^" C, k! O" o4 k2 O# q7 b' S grid-y-inc ;; the amount of patches in between two roads in the y direction0 g5 \" B# k. f* ^' z0 N8 }
acceleration ;; the constant that controls how much a car speeds up or slows down by if+ J( l y$ O4 H- @
;; it is to accelerate or decelerate* s6 S8 h3 K6 Y8 W M
phase ;; keeps track of the phase" p% @, v6 d5 F1 B. e: S) w6 H5 J' o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' v, n0 d! F6 d3 y- r% ^
current-light ;; the currently selected light
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) v$ z# G8 n8 k" l0 { ;; patch agentsets
# O* {- t3 P4 I1 [! G; H/ q intersections ;; agentset containing the patches that are intersections" g: x7 r8 {& {
roads ;; agentset containing the patches that are roads8 c5 d9 {1 O9 G* M* J
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turtles-own
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speed ;; the speed of the turtle
# i( a$ y; X8 s# B up-car? ;; true if the turtle moves downwards and false if it moves to the right9 T# U6 x, W" k
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: U: `; ~5 o8 |7 w6 x/ J( E: ?
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 o; @. z; \* r Y$ T ;; false for a non-intersection patches.. w, x6 W1 N2 \1 k K- _
my-row ;; the row of the intersection counting from the upper left corner of the4 K8 V B6 D& ^. e$ y; H& {4 e& b9 n& Y
;; world. -1 for non-intersection patches.! l) X- Y4 g; q4 l5 ?3 s
my-column ;; the column of the intersection counting from the upper left corner of the0 w+ O' m r* v+ _+ l9 j* o/ ]& S, e k
;; world. -1 for non-intersection patches.. S- J9 Y* R4 o+ f6 C
my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 O7 Y3 n8 h) |+ f% H" Y* S
auto? ;; whether or not this intersection will switch automatically.
& n4 W4 E9 X) D8 R1 K# | ;; false for non-intersection patches.; u6 Z& |3 ~$ q5 P! ]
]
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;;;;;;;;;;;;;;;;;;;;;;1 q( n% |( v. o$ _3 V
;; Setup Procedures ;;
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* J9 L) |8 F. X4 w3 I;; Initialize the display by giving the global and patch variables initial values.
2 [3 G7 w7 n8 r' p/ O2 a8 q;; Create num-cars of turtles if there are enough road patches for one turtle to9 k5 l+ H" e( S; D
;; be created per road patch. Set up the plots.
3 c# y9 a5 I$ M* X5 Y8 wto setup
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& I& X* \! N& G+ m& Q5 @0 E* O setup-globals# ~. F7 A* C$ g
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;; First we ask the patches to draw themselves and set up a few variables7 O1 ^! [2 L, F$ y
setup-patches
, T' c9 t1 `' G: |9 j6 ?( d# S make-current one-of intersections
" c# f) x7 `! ~; @* R; W5 G label-current4 \" j! b) h I @" I
2 i. E* D( H6 N6 Y# D% G# X set-default-shape turtles "car"0 O3 f% S! y0 n
/ I% B# g- N9 T if (num-cars > count roads)' L$ P4 b$ O9 [" y
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user-message (word "There are too many cars for the amount of "
2 x+ q8 p! s$ }2 Y ]( z% r6 |: d "road. Either increase the amount of roads "
2 _/ |/ M3 W. Y3 j! p% h# D8 C "by increasing the GRID-SIZE-X or "# a! P2 d, d4 {0 D
"GRID-SIZE-Y sliders, or decrease the "
8 A! W, ?+ _, G7 E. ~: g "number of cars by lowering the NUMBER slider.\n"
5 K% P( j6 `2 k/ V u* d "The setup has stopped.")
+ o; T3 d- M5 x" ^9 q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 ~3 ]# F" u& @4 U
crt num-cars4 \( P' U; [4 S$ j) r$ \1 r J
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setup-cars" Z9 x" K+ N0 o$ j" q
set-car-color' k4 M: O, F: H. G' s
record-data4 X) }0 U( {& J1 y! z4 n
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, O$ c+ ]# o& v# \ ;; give the turtles an initial speed! m5 ~: b A* L7 T; c( d
ask turtles [ set-car-speed ]
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9 j7 h3 P! f% p6 U# [+ M, Y reset-ticks
1 d4 d; O& `5 P: Q' G7 Y; tend
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;; Initialize the global variables to appropriate values
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! W/ C) P3 Y) U X set current-light nobody ;; just for now, since there are no lights yet$ R$ c p+ t& Q4 C4 `, T4 A
set phase 0- p& o) U4 g K. J9 x
set num-cars-stopped 0
7 V, u% G; S# g, L5 n- x( {5 E/ I" R set grid-x-inc world-width / grid-size-x
6 I* _# }5 N; c" L1 P6 l set grid-y-inc world-height / grid-size-y+ Y; R# s4 p2 \/ y2 t6 c* \& y
' c+ b9 A% h/ D9 u7 B ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 q+ b) b2 x3 z0 n
set acceleration 0.0999 T7 d0 f6 i$ E" Z- T4 M
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% P# E; ?" J6 @( }$ Y;; and initialize the traffic lights to one setting6 J. Q1 ~$ c4 u4 M. V
to setup-patches
. C8 R+ ? w0 v ;; initialize the patch-owned variables and color the patches to a base-color% @" H/ b4 E# {% ^& d% s* H' I4 L
ask patches
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set intersection? false
) i% a& N# U9 y8 q( R1 k1 Z set auto? false! l+ o. e h- ]* _' u6 k/ h* ^
set green-light-up? true0 t/ Q- l! P' {+ B" F
set my-row -1
" X( U; i" q% E$ R3 A5 t set my-column -1
% F4 }) e( v) U8 N9 ?0 q set my-phase -10 j7 w1 P3 D' o% G
set pcolor brown + 3; T9 j7 ?) q0 e. C) \6 y# E
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, X; a' I! B6 n9 b: p6 o ;; initialize the global variables that hold patch agentsets
1 `" z/ Y l7 c5 K$ f7 ?; m0 z set roads patches with
9 o$ k4 q9 A' o: } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, j0 F ^, }, p& q) M: C6 T q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ I/ d" P2 |* r- ?& j
set intersections roads with
3 U, D0 ~) u( b! @% W: u( L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! q: k" B0 e6 g! q& ^5 E5 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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% y7 H* X4 a; mend: _! d! g2 S. L7 n- X. ?
其中定义道路的句子,如下所示,是什么意思啊?) ?* F; y; E6 Q0 k. W, B
set roads patches with
$ o) M: T4 f* |0 M" j; ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' _! v8 |0 X+ [# y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 a# d2 j. C0 M7 F. Y' 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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