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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。. X# y& K+ c6 W3 A- [4 M
netlogo自带的social science--traffic grid这一例子当中,
2 o, H/ S3 r" u4 V) Wglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
* w$ a1 t( F- f2 i grid-y-inc ;; the amount of patches in between two roads in the y direction, ]/ Z7 v4 h1 a) e4 a1 [2 w7 m
acceleration ;; the constant that controls how much a car speeds up or slows down by if
: H0 |# [# {6 _! w8 F% ] ;; it is to accelerate or decelerate! _7 D, K" K$ V$ ?( j4 i
phase ;; keeps track of the phase
3 c0 P# Y) `( } num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 i! e( e1 j) j1 G x
current-light ;; the currently selected light
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;; patch agentsets
; n- A# p! c' n- R; }* z6 L' s. S intersections ;; agentset containing the patches that are intersections
& |! O7 g* S1 [% j2 ] roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
; h9 J: Y) q1 ?2 F" h3 s* s2 A up-car? ;; true if the turtle moves downwards and false if it moves to the right0 `$ G, R% a$ x" o& s0 Q
wait-time ;; the amount of time since the last time a turtle has moved
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2 K. @% H& Y) u& V4 X7 J( d! Z$ ipatches-own
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- H- s% r' B; u6 @ intersection? ;; true if the patch is at the intersection of two roads) ^, n X, W0 H# I2 N, |6 r
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! ?; j, |1 `' A$ P; [5 [ ^ ;; false for a non-intersection patches.3 P5 Z4 ^! Z5 q t. c$ S- m: b
my-row ;; the row of the intersection counting from the upper left corner of the
7 ^: I7 }3 s) {$ t1 o ;; world. -1 for non-intersection patches.7 h% K) [2 q9 R. @5 p
my-column ;; the column of the intersection counting from the upper left corner of the
! |. w$ e! q! R5 J+ s ;; world. -1 for non-intersection patches.
\# a9 ^& T: k: a* A my-phase ;; the phase for the intersection. -1 for non-intersection patches.. m# r2 i9 p+ q6 q) [* W% A
auto? ;; whether or not this intersection will switch automatically.
8 s) k% j% a6 p ;; false for non-intersection patches.* r' j2 r/ x# t3 w3 d1 C9 E f A
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;;;;;;;;;;;;;;;;;;;;;;
% }+ W( [. L7 |) u1 ^. u;; Setup Procedures ;;8 w4 v8 _' j q! ]" Z6 l! |
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;; Initialize the display by giving the global and patch variables initial values.* T; S* p y8 g; x( k+ Z; u4 t
;; Create num-cars of turtles if there are enough road patches for one turtle to
F" V0 W4 [9 j6 r+ Q) K( x;; be created per road patch. Set up the plots." z3 t0 r/ w7 X$ S6 ?9 a& G
to setup3 j: b& X3 K6 U" D
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setup-globals3 v! w- U" I7 x( ]+ O
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;; First we ask the patches to draw themselves and set up a few variables
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8 U" A: ~/ T( D) S; U* N6 v+ k make-current one-of intersections
$ \) _2 y/ n3 Q1 i4 \7 g/ \, D( @ L4 R label-current+ i: ]2 S9 K$ o8 }: M4 B
" o9 Y: ?) N8 U" R) } set-default-shape turtles "car"+ F, I" N8 L: y2 L7 b9 i1 W
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if (num-cars > count roads)
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& z! K* n7 v6 l8 T0 w2 E- _ user-message (word "There are too many cars for the amount of "
+ ~$ | a/ F# d- |- j/ F. T" `; _4 Y$ \5 R "road. Either increase the amount of roads " s7 m8 I# p8 b
"by increasing the GRID-SIZE-X or ": P2 A3 p' L% k( t a0 o
"GRID-SIZE-Y sliders, or decrease the "
* O( b5 [! z' |* [7 [6 o "number of cars by lowering the NUMBER slider.\n"5 e5 h/ R6 Z$ j8 }
"The setup has stopped.")
& G4 d; H2 m$ [# o stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& n: G# x2 p! W! Y8 I
crt num-cars
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setup-cars: w; H, Z3 @. H, F& x" [
set-car-color9 v% M9 y' t4 l5 r
record-data
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& C* r3 N0 C k% r2 R! V ;; give the turtles an initial speed
s: V6 L6 k8 ?" m, o1 _ [; p ask turtles [ set-car-speed ]- R9 q+ V! H5 r" k4 B% g& e! S
( `1 A/ |* e0 Y3 P ? reset-ticks
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0 W# d) U5 _# z7 J;; Initialize the global variables to appropriate values
% p m0 \ _6 Rto setup-globals
1 Y5 H+ g6 g5 _4 g set current-light nobody ;; just for now, since there are no lights yet9 N# _" j/ y2 ], t& @* K
set phase 0
. ?% i" N ]- x8 m- h: _ set num-cars-stopped 0% |- x% ^0 V7 A# |, k
set grid-x-inc world-width / grid-size-x
- K# s$ f4 h' ]0 h0 V8 ^4 R 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
! {" n0 N1 k7 x+ w9 b& ^& g& S. Z set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: a. d2 T! l" a6 f+ Z
;; and initialize the traffic lights to one setting
& v5 {. v/ S! \# oto setup-patches7 ]. A9 v: ]. d$ Z
;; initialize the patch-owned variables and color the patches to a base-color9 Z( D* P- ~& M) V
ask patches
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set intersection? false
* d; ]. M e6 g' f set auto? false4 V* H% g% r% Y! p" f2 j+ Q; g
set green-light-up? true
- Q& O+ w; X8 p. O! ~ set my-row -1
8 `$ k1 X2 l% u! B3 a0 H1 f/ o' q9 K set my-column -1& c, h: g7 V; m+ f- m
set my-phase -14 L7 t% O% l! s j! Z
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets0 l7 S/ g) x3 H* u& o$ ^* ?4 ^
set roads patches with
" M# f5 Z6 X0 I% P* ?9 J3 I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! z# X. b8 P6 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) K8 n/ A& s7 g, {7 w
set intersections roads with5 }5 g+ R9 \" e, W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ r$ U T' ], e2 d5 I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; A) I R2 Q# W: {: Z- G# p2 k ask roads [ set pcolor white ]
+ V* f+ E# ]% c0 q; @. Q+ n 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?
$ d. o% x {0 ?' H! p+ i set roads patches with
$ g8 K. M" f4 Y+ s! F/ m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 p* O- k. d% e5 t) L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 K7 x5 H* V0 x5 X4 t% F/ ]7 K
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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