|
|
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。- E! H' I# H0 u) z
netlogo自带的social science--traffic grid这一例子当中,, R4 g( i7 s5 v
globals
( k! P' L# a: v0 S# Y3 i4 I# t[' r1 |$ G. q! q4 _* U5 \! |/ a
grid-x-inc ;; the amount of patches in between two roads in the x direction
0 y; I: m/ g9 o, ? grid-y-inc ;; the amount of patches in between two roads in the y direction( q. s% @" [4 b
acceleration ;; the constant that controls how much a car speeds up or slows down by if5 U! \$ l9 ^' j" f$ W6 a, o C
;; it is to accelerate or decelerate
4 ^, p' c; r8 I# w- T phase ;; keeps track of the phase
, ~/ k) C6 Y' w num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 m+ L; {2 P, }1 C current-light ;; the currently selected light
. `, r) y3 a f: V5 ^" B3 f1 v7 s
;; patch agentsets
) c7 h5 a* o7 p/ j% ] intersections ;; agentset containing the patches that are intersections
- h+ [" Y7 n3 {8 ~ roads ;; agentset containing the patches that are roads
$ |) f1 a/ w! K; d/ f]
( x2 z: g4 D$ q! F9 s4 K
2 h' m8 t; P9 Q5 X3 J3 w+ l- M* q! ]$ eturtles-own
1 e% V6 {: t- q' w& L$ e" R[5 ?$ q# V6 e+ p$ y; U# U
speed ;; the speed of the turtle/ P7 |9 d3 D7 S! t, K
up-car? ;; true if the turtle moves downwards and false if it moves to the right( B! O- F( y a0 g% r
wait-time ;; the amount of time since the last time a turtle has moved: d+ I r- D8 Z3 p( d' ]6 I. G9 [
]
0 f6 ?) H+ p# {' Z# a# ^2 R% @8 `- @: w6 f
patches-own
/ ]0 ^! ^6 F w; X: j[
" b- O5 U0 o# p intersection? ;; true if the patch is at the intersection of two roads
% |" J3 s3 M& V: c green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ }( {+ f( _; i( ~6 @4 e ;; false for a non-intersection patches.
3 Q4 L( w; C( u2 v- q& b9 @7 l$ ] my-row ;; the row of the intersection counting from the upper left corner of the. ]1 Z: s) F" R% `
;; world. -1 for non-intersection patches.
9 L2 x+ _ Z- {" x my-column ;; the column of the intersection counting from the upper left corner of the
) ?) m: ^) A& z ;; world. -1 for non-intersection patches.6 W: E3 o+ M7 L
my-phase ;; the phase for the intersection. -1 for non-intersection patches.. W! c4 c+ n, E% J; t
auto? ;; whether or not this intersection will switch automatically.* A0 X/ v5 q- F o+ @& I* q; v0 ?
;; false for non-intersection patches.
, p; l6 K0 G1 C2 u y9 O]
, d; K+ m$ @0 l* q9 f8 y) b9 m6 ?0 g/ e. k8 A2 E7 I1 ^% F0 a
8 o2 Y; R H- k7 T;;;;;;;;;;;;;;;;;;;;;;6 x1 a& W3 Z8 W; `# w- W/ O |
;; Setup Procedures ;;
' \1 G$ ^" Z9 u0 R3 V( L;;;;;;;;;;;;;;;;;;;;;;
. @; f( a' w0 S. o' \! i. o0 A! V- ?6 {8 @
;; Initialize the display by giving the global and patch variables initial values.
& b# C6 r5 f5 L! k2 Z$ u v" G;; Create num-cars of turtles if there are enough road patches for one turtle to
0 C2 k" M R6 y2 X2 W P;; be created per road patch. Set up the plots.
. p/ P+ d9 ^4 s2 W/ ~to setup) F9 T, [, z1 {. h# F
ca* n5 Q i* D; c: ]) h V6 T
setup-globals9 m2 Q, j9 V2 M+ r% R2 X+ \
a- z" {8 X( r8 r/ |9 h) ^
;; First we ask the patches to draw themselves and set up a few variables& O3 {7 c( j* z) X1 g' f
setup-patches
3 |$ Y" u& t7 Z! K, j6 ~ make-current one-of intersections
" }% ?4 X- L+ o. P" x- Y" }" _; J label-current
# A* P& K: g9 _5 Y2 {7 s4 F8 [5 j \. D7 i
set-default-shape turtles "car"& j# e+ M$ M% | W! F2 w
2 n' |1 X6 |& E4 w7 c5 Q( { if (num-cars > count roads)
$ a% [" w3 j. H$ B [6 c2 E( |! J$ s+ N
user-message (word "There are too many cars for the amount of "2 |8 ^8 {0 ~: h0 L+ j
"road. Either increase the amount of roads "2 {4 Y% _, W6 [1 f% d, L, d
"by increasing the GRID-SIZE-X or "( s' d! e% ^0 S2 i" A |: ?* _# ?
"GRID-SIZE-Y sliders, or decrease the "' W, {* |* F; s& a
"number of cars by lowering the NUMBER slider.\n"2 Z3 t4 r7 U& A: }5 H
"The setup has stopped.")
, B9 R6 ^" s, ]) _2 ^$ H/ `' f stop
# \- o# E6 G# Z ]
; j# \8 u4 O$ B5 T! S6 y" m- @2 [$ s2 [4 E! y
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color ]7 M. l1 i* K; m" m; w k- L/ u
crt num-cars3 |! R V$ Y A& }# ^
[
2 I9 b% s: H( Z setup-cars
; U1 f- F& X C! c; B set-car-color
* y: q2 o: K, g/ m# o5 H record-data
, J, [6 P5 [9 m* }: B8 K) [- c ]" |+ |" a1 s" @ ^
3 {' z/ v; t' k: c+ b& J' R
;; give the turtles an initial speed
2 ~$ _ v4 P% P0 N5 @ ask turtles [ set-car-speed ]! h. e5 b" \8 c4 k1 }* p
^+ H. Q& E, k* P3 z2 y, i- Y
reset-ticks: A5 z7 I# W% E1 K
end
! q- |1 g4 G$ |; S& L6 q6 I4 |2 w
# X' ]2 I3 W% d6 u* j;; Initialize the global variables to appropriate values
- [; M: z. ?2 i" L& g$ g6 Zto setup-globals
1 d5 h( O! K' U. z3 c, ~* y/ } set current-light nobody ;; just for now, since there are no lights yet
- A" m8 l; W6 J q2 z' A2 T3 N set phase 0 [0 h( o. b3 V) |# ~
set num-cars-stopped 0/ @ O/ i" l5 n# `7 V6 J
set grid-x-inc world-width / grid-size-x; T! B. S* p0 ~3 V4 R
set grid-y-inc world-height / grid-size-y
7 j8 y8 ]0 F& X" P, h0 O! J+ m! n2 T1 t. d
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% |: |7 L( Z$ Q* S9 p set acceleration 0.099
1 }: b2 t6 O, E5 u6 }end
2 k$ [8 {7 D- C g
0 ] y& c! u- ?" ^9 W! q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ m& \; e" l. @;; and initialize the traffic lights to one setting- f) B# u. {; N9 j) S R
to setup-patches
" r: {5 ?2 ^) _: F3 }/ i1 k" h9 H ;; initialize the patch-owned variables and color the patches to a base-color- N9 M( ]& z& `% y+ h9 a
ask patches! x; n# I6 {* n
[/ [1 M- E0 X& x: b) F" ?
set intersection? false
! }9 C s% q2 |+ f set auto? false& L: r$ [3 I7 D2 J0 X$ ]& B
set green-light-up? true! L7 Q% s" B4 @; n4 J4 J
set my-row -1$ y# [( v. ?/ h0 h$ x3 L
set my-column -18 t1 H- T9 h; S* t1 g" _
set my-phase -1
& \1 C, Q7 w$ o set pcolor brown + 3- D+ m+ W) S! }& D" G
]
. N' n$ D9 _5 A# Y" {' I! i4 z4 `2 n6 @, z% e! X# u7 S
;; initialize the global variables that hold patch agentsets, ]9 G& V* ~: O! d* ?$ \
set roads patches with
! b5 e" b0 [" u' L( _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 y" U6 |6 u/ y6 o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ V O9 s5 B2 S, ?/ A+ V set intersections roads with( b) m' d# i$ ]5 B3 y: O# }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. B% Q) X9 r: i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ t ]8 w% R8 ~2 K8 G; B
' h! X/ g* V' L* T$ ^ ask roads [ set pcolor white ]
# h+ O% N* n* e U* B setup-intersections* \& B' Q. o* u# ]( i+ H6 O! Q
end! V L8 \" c5 T- \
其中定义道路的句子,如下所示,是什么意思啊?
0 |4 t4 E0 O! d- }0 X set roads patches with
+ c( M6 H5 T0 ^( N$ C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: p7 v; T q! P2 A/ q% M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% G1 z+ e$ v0 f+ w) @. 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? |
|