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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 e0 o, J, T Z8 Y; M/ s. @3 p
netlogo自带的social science--traffic grid这一例子当中,
g8 S/ g, k) A/ {! zglobals1 P7 C) |# ?0 F' M2 a/ O; r* I/ e' ?
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grid-x-inc ;; the amount of patches in between two roads in the x direction9 b7 a# l9 D/ I5 U/ I
grid-y-inc ;; the amount of patches in between two roads in the y direction o" z# x) V7 N
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 p5 n1 t- |, Q: e* p ;; it is to accelerate or decelerate
( R7 U7 ?: J+ v5 R& ~. v phase ;; keeps track of the phase
3 C# v& W7 u& G! q( M' {8 q1 @ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- b$ E! F" f2 r current-light ;; the currently selected light
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" f, }: w: h" U3 ]) `% q f ;; patch agentsets
! }8 }! x- E" ]3 h2 {& j# ]. x intersections ;; agentset containing the patches that are intersections
0 E! _& V0 l P/ V* E3 | roads ;; agentset containing the patches that are roads
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turtles-own: S( |1 G) c; n B1 \5 w6 B9 e# }# e2 V: J
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8 P) h% a/ q4 f. Y$ P# D" x* T! @6 s speed ;; the speed of the turtle
+ ?* H# D, l/ B. v$ Q: C s0 | up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 [' Z6 k* X1 V$ {4 T wait-time ;; the amount of time since the last time a turtle has moved
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# f! Z. y9 c8 g, Npatches-own* v: E1 O: H4 X" o9 m. I
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8 J' L! A& K( }& \" \ intersection? ;; true if the patch is at the intersection of two roads
* |5 g( E( A+ Y! e& c& `/ H! C F0 } green-light-up? ;; true if the green light is above the intersection. otherwise, false.- h5 l1 K2 y. S& K' ~
;; false for a non-intersection patches.
% L+ s$ Z9 B( ~6 m: u. |0 y% l% z my-row ;; the row of the intersection counting from the upper left corner of the
. `- H2 M! H- Y! q( Z' I ;; world. -1 for non-intersection patches.* H4 N$ ^6 w2 I. A& u
my-column ;; the column of the intersection counting from the upper left corner of the4 h' l# j/ ~ P. v8 L I( `2 a
;; world. -1 for non-intersection patches.2 Z4 U6 k# H. _6 N0 r
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( x$ {# F/ W: m$ ~. S4 K# u' Z auto? ;; whether or not this intersection will switch automatically.
8 c) T5 s3 Q" d2 C U3 s6 o ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& |0 R/ N; i5 K; [
;; Setup Procedures ;;7 U( [5 M& J) M+ q) P$ r
;;;;;;;;;;;;;;;;;;;;;;
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/ C1 P5 p, _: D& n8 u' g;; Initialize the display by giving the global and patch variables initial values.) O# c u/ r6 n$ P) a% f8 [; _
;; Create num-cars of turtles if there are enough road patches for one turtle to. y; H5 s3 Y ^/ D, u. ` x
;; be created per road patch. Set up the plots.
: N8 c! Q; L+ _: x3 lto setup
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6 R" Y9 f2 g) A3 P setup-globals
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$ H( d, ^! k0 M5 x! D6 H7 ] ;; First we ask the patches to draw themselves and set up a few variables
" Q- S8 m/ D9 ?& @* C setup-patches) F$ q5 q+ Z; d0 _
make-current one-of intersections
1 I9 t& |' H w1 q. t label-current
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' o& z; @: N4 F& ^% B set-default-shape turtles "car"% _1 [ k) w, ~" Z) w9 o
* U4 x4 E# Q" V0 e& y if (num-cars > count roads)0 C. s( }; K* A" x. _
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2 W' ^: i* y6 x6 H; N, @8 `' b user-message (word "There are too many cars for the amount of "' @( L+ m7 x9 t# s3 S5 a* r% f
"road. Either increase the amount of roads ": O8 C7 Z1 k5 l5 W4 R
"by increasing the GRID-SIZE-X or "! l7 c2 V6 R$ D5 n
"GRID-SIZE-Y sliders, or decrease the "
9 d5 Z7 ? }: y/ E( K$ w5 A) { "number of cars by lowering the NUMBER slider.\n" `+ P, u2 X5 V" \2 f8 u$ A: R/ h2 l
"The setup has stopped.")5 W2 i/ L0 W, A7 X+ O
stop l3 ?' N+ B. z
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! e9 g7 E% [# j* n! H' d ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ d& U) a. p6 [
crt num-cars
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setup-cars6 Q% T- \3 A2 ^. A; a
set-car-color; }3 \! \: I, I! _% T
record-data, `& G) }" Q0 p& n& B
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;; give the turtles an initial speed
; {5 `. ^2 q8 }( K+ F ask turtles [ set-car-speed ]( T( K4 F, i: I7 H7 X
3 [9 u+ r' {, Z" h/ H' M reset-ticks' e0 p3 {$ g: z) ?9 S3 ]
end) I- O G3 ]$ k8 T
' A" C% t, C2 c- n- j;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
! y' o+ m7 q1 C/ | set phase 0
1 U- P' {: h1 @, s set num-cars-stopped 0
9 \* c1 l) s$ U4 A4 L9 Y: D7 i set grid-x-inc world-width / grid-size-x2 D8 G3 R) I/ L# A1 x7 P' R, d
set grid-y-inc world-height / grid-size-y5 j5 D% T ]9 {8 {
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 l) d, V. Z4 k* ]3 o
set acceleration 0.099
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/ H" ~/ w' Q" ~0 Q. g;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! F( p* w9 M$ @! U8 c x: o4 Z
;; and initialize the traffic lights to one setting
* s) a6 m8 Z5 q" s7 p( s9 Y* u# nto setup-patches" Y1 i! t9 {: H) S1 Q' K
;; initialize the patch-owned variables and color the patches to a base-color
4 G P& [: w% Q ask patches7 z; d6 i7 M2 e+ d4 `
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9 q) ?5 {% V3 D, o2 s% ] set intersection? false7 E) b. I$ P9 p
set auto? false
8 E8 F$ T5 Z' L e set green-light-up? true
_$ P$ S2 Z& E3 _ set my-row -1
, @" L* g+ [1 y, Z3 p( H$ Z6 T set my-column -1( v; Y6 }; T% O# Q, U* ]3 g
set my-phase -1
: j" v+ @# A1 @) ` n: U set pcolor brown + 34 ]9 _! g% p6 S. e* @5 z" E7 K9 e
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;; initialize the global variables that hold patch agentsets
1 E d) h, Z0 X set roads patches with' C$ S3 W) j' C4 k! m$ a/ H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ [% x; G4 E* X7 z% I( z$ J+ {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 u$ r: Q- B' J
set intersections roads with6 V7 v0 Q4 K- K) P4 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. V# e" }6 L. u4 B3 P: d9 V4 T# l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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$ L3 y- Y5 W- |* |' q0 M2 g7 G ask roads [ set pcolor white ]
' H: t5 ?+ C& o8 u# u7 j! J, H setup-intersections$ p" L; f4 z: o/ m0 T
end0 s' g1 j+ O7 J+ r. M
其中定义道路的句子,如下所示,是什么意思啊?
( S8 S) q" c; M, r5 { set roads patches with& [! G5 B: `) F. V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 U; a2 O+ }5 \# [" @9 A& C+ E% ?" K# g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 b/ O4 T: s m
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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