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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 q8 j- h2 m3 t O+ S8 f) z& b, onetlogo自带的social science--traffic grid这一例子当中,
% Y7 ]- Y$ j% _7 M5 Jglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( E+ U5 H! y% q4 j8 {
grid-y-inc ;; the amount of patches in between two roads in the y direction6 k6 {8 u" Z8 q2 f3 ]
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 l: l; `* y5 O- l/ V ;; it is to accelerate or decelerate
* V5 s1 k+ L) y phase ;; keeps track of the phase
. [. L; @: v4 h m* Z: G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 b4 v! _( t% r! {0 G7 V- `+ T- C current-light ;; the currently selected light
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9 b5 ]; i% B t# S7 _$ A3 H ;; patch agentsets- y# R6 F6 e1 ` G, z7 f1 ?* \
intersections ;; agentset containing the patches that are intersections
# N3 u' }9 i" p roads ;; agentset containing the patches that are roads
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turtles-own: x1 i' K. @0 Q' ~9 d/ }! L+ V
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speed ;; the speed of the turtle
, k, X+ s! H4 L$ R up-car? ;; true if the turtle moves downwards and false if it moves to the right
@* ~# Y( D' D l wait-time ;; the amount of time since the last time a turtle has moved
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$ V' {- [4 E* o* u" |" N9 Fpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
8 m3 L3 A6 p0 z9 w1 J green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" Y' r$ J5 h7 j2 q/ B! g3 O ;; false for a non-intersection patches.# \5 f5 i& n" R9 a( M4 A, N
my-row ;; the row of the intersection counting from the upper left corner of the3 r. c |/ x4 q3 f
;; world. -1 for non-intersection patches.
# L/ i5 X5 j; Q my-column ;; the column of the intersection counting from the upper left corner of the
0 r5 X6 g/ P5 F/ y3 D. V0 y ;; world. -1 for non-intersection patches.% X. Z5 M) g' L' {& i# |- A
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 R2 k- Y" r% d1 X8 ^. Q5 W1 i3 t auto? ;; whether or not this intersection will switch automatically.9 ~! V- ^1 T) R! \( V# ^& ]" p
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
3 r# N" w% z2 d* g8 w9 u;; Setup Procedures ;;) F0 A0 i) ]6 D( |& ` ?& ~/ N4 x
;;;;;;;;;;;;;;;;;;;;;;
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; A5 v3 |1 y8 r/ q% ?;; Initialize the display by giving the global and patch variables initial values.+ H+ p8 b' O2 u; u6 x
;; Create num-cars of turtles if there are enough road patches for one turtle to
, Z" R2 r: m: y;; be created per road patch. Set up the plots.
7 ]1 t6 `7 Z D8 E6 g2 u) m/ tto setup
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J+ y2 j) @5 `4 f' v setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
$ M' U) U. f7 S( c; z setup-patches# n/ \$ L2 }! @% J9 E
make-current one-of intersections
4 e. ~8 {% f) V' \5 e. {) g label-current
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2 n, z! m" H6 B# T) i set-default-shape turtles "car"
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if (num-cars > count roads)' d( |2 u4 L5 Y( z1 a* x
[
7 Y) t' U+ Q7 F) q0 S0 h# \2 E user-message (word "There are too many cars for the amount of " q' p/ {% M; A4 Z
"road. Either increase the amount of roads "
8 E" s* p) x, x "by increasing the GRID-SIZE-X or "; l) h4 S8 ]' S. d
"GRID-SIZE-Y sliders, or decrease the "* W, w+ B6 c% {1 B! R) c
"number of cars by lowering the NUMBER slider.\n"! V. Q0 h( h0 O
"The setup has stopped.") x- ?6 t: d' x% E
stop
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% h3 g, e$ U$ a8 ]9 r" Q3 Q2 \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 k8 z9 P6 @6 _: ? G
crt num-cars
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setup-cars
8 I6 a8 h# @, `$ R7 [ set-car-color3 z1 p; y- E2 a2 w& H* g8 g
record-data
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;; give the turtles an initial speed
. O1 ^* ^0 r: W% S ask turtles [ set-car-speed ]$ C3 i. g# g8 D# J3 ^1 H7 R, p
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reset-ticks$ Z4 A3 X3 L( `$ l
end
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$ ~( l5 i5 ~; [, g/ u2 Z;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet1 k$ ?& Y( \% k
set phase 0. K/ E, r. K' {* k8 O0 l$ J
set num-cars-stopped 0
# M" ?( h* V6 h) |6 {" u! i set grid-x-inc world-width / grid-size-x
# g! a+ h1 |% v8 Y& c 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
1 L8 q# I( l ~: i set acceleration 0.099; [7 ^" G( c1 X
end' s! ?2 P, E) A7 q
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 K. w& Z$ H6 h8 [2 H' k! W;; and initialize the traffic lights to one setting1 P- l9 v" ?# H
to setup-patches
\: M% {, Z" c6 Q2 N3 J ;; initialize the patch-owned variables and color the patches to a base-color
# {) Z) l4 q" R- r ask patches7 p( ?' {+ G0 i% \1 y# Q) B( @$ H7 @
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set intersection? false( s( c+ h+ V! \7 L: M
set auto? false" A3 G4 k/ F5 `( d) r
set green-light-up? true3 O5 s- S5 ^$ W1 @
set my-row -1
3 E2 I7 Z( d' L0 i3 x p: l set my-column -1& g( x( a0 L9 v+ U
set my-phase -13 G! ?, k, c5 V4 a! {1 {
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets# V; D" ^, W" C; a& D2 x. B
set roads patches with
- R' `7 P8 k( {; c1 t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 {; U: c- y; F T8 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: T1 V& Y# L1 t! w7 l
set intersections roads with2 Y% s, S& t9 [* u3 Y* R8 B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 }8 a- D2 Y9 I0 V0 C8 F6 b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]2 I3 x5 D: N0 T0 O2 d7 C) \
setup-intersections
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; H- Y6 |1 S) Y其中定义道路的句子,如下所示,是什么意思啊?
1 m( w2 N0 h' ?% Q1 | set roads patches with
: O0 {! k. F, ?; u1 i7 N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ j1 q* D7 V6 O- U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; `" v1 e+ O! i0 }0 B; q9 ~ z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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