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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。 ~+ L' k: r8 \
netlogo自带的social science--traffic grid这一例子当中,
0 V& z6 p, _& e' }* Nglobals
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8 g8 m4 a3 N% ?, P2 ~( `( l- M grid-x-inc ;; the amount of patches in between two roads in the x direction! p3 o7 B8 u$ m# H1 T' Q7 b+ v
grid-y-inc ;; the amount of patches in between two roads in the y direction! P' _! J3 Y& M2 _
acceleration ;; the constant that controls how much a car speeds up or slows down by if* {+ I+ G) b$ J; ?$ x0 G5 a
;; it is to accelerate or decelerate
; O- z+ x+ M3 |9 h% _% k phase ;; keeps track of the phase
]4 K9 h$ V: \# Z. j num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- b- k! f3 y7 ~/ A current-light ;; the currently selected light, g1 Q3 h3 L f8 K- _! }" V8 p2 J
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;; patch agentsets
, r- I3 u9 S' W+ R5 b3 c+ i intersections ;; agentset containing the patches that are intersections' C' Q, K+ n# ~, [4 x7 d& f
roads ;; agentset containing the patches that are roads: ^7 G8 Y- }6 U- W
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turtles-own
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$ P5 {1 d: Z# \9 g& l% L speed ;; the speed of the turtle9 X# q% A6 ^ J$ V0 s
up-car? ;; true if the turtle moves downwards and false if it moves to the right
9 F) X2 i( H6 d: H5 s wait-time ;; the amount of time since the last time a turtle has moved
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9 s5 A5 w5 e) m- I N4 c! X: Dpatches-own1 j6 U6 u% w8 @ R/ W8 H
[
' L7 m. x* c- P* I9 F) T intersection? ;; true if the patch is at the intersection of two roads6 N: A8 n! l2 U y5 Z
green-light-up? ;; true if the green light is above the intersection. otherwise, false./ ^- T9 Q- P5 F$ ^4 K8 O
;; false for a non-intersection patches.4 d7 b8 S! i0 d4 V' N, M/ Q
my-row ;; the row of the intersection counting from the upper left corner of the
; v9 F+ L8 K* \) e0 a; {/ `$ z) x ;; world. -1 for non-intersection patches.) H3 W* t4 p! X2 ]4 |1 ?
my-column ;; the column of the intersection counting from the upper left corner of the
) S: {) X9 X9 Z* i ;; world. -1 for non-intersection patches.
* S4 k8 Y4 O+ O) a my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ g' m. O) E1 w7 M) I0 k auto? ;; whether or not this intersection will switch automatically.9 @" m5 }3 F/ ?
;; false for non-intersection patches.6 `* l. F9 F: E! ]( W
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8 [1 N0 g( q- t;;;;;;;;;;;;;;;;;;;;;;3 `8 k& Y8 l" M. }6 O( I0 N( r
;; Setup Procedures ;;6 V( O; ]$ R" _- [/ N
;;;;;;;;;;;;;;;;;;;;;;
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1 r1 `* X1 m7 E+ i;; Initialize the display by giving the global and patch variables initial values.
, _7 Z+ E% w5 Z B1 ]8 l) x;; Create num-cars of turtles if there are enough road patches for one turtle to9 V- y D) p9 G$ @* u- f8 d% Z$ j
;; be created per road patch. Set up the plots.
. @4 e5 P0 X! @. w' O4 [6 Tto setup# p, w2 `& c+ |. o; [- b6 U! _0 m
ca0 s6 Q* v& f4 \/ J$ ~, a, ?9 O
setup-globals6 V A& J5 x' J: Z/ M
7 n g) i; y7 J1 _5 \ ;; First we ask the patches to draw themselves and set up a few variables5 t+ `* o4 W; E' `$ L
setup-patches( } W4 }9 H) [% D
make-current one-of intersections3 X+ r# U/ `3 i/ j3 i+ F
label-current
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, y; w2 ^8 ~' x5 _' f" o4 ?$ m set-default-shape turtles "car"
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if (num-cars > count roads)
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7 f( w) r9 ]% ]; f' W2 o7 N user-message (word "There are too many cars for the amount of "
7 r6 }8 f% I2 j" O. p2 | "road. Either increase the amount of roads "
+ l" B+ Q1 Q0 d: Q. q "by increasing the GRID-SIZE-X or "
/ x7 X6 P7 i5 v "GRID-SIZE-Y sliders, or decrease the "
6 F4 b$ g. P+ @: `5 k4 `* d( t "number of cars by lowering the NUMBER slider.\n") |+ q/ a: a. n
"The setup has stopped.")8 \ P4 [1 `7 x) I# H2 A
stop( E) E m6 O/ w3 a& ^1 X
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 J6 ]- N/ P9 q1 f, A1 R/ z, c
crt num-cars$ \$ `! p' V* O3 a
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setup-cars0 l. g/ m1 L% S3 h
set-car-color4 E) Z, X5 O$ ]; u
record-data" y- t( Y# W8 f2 g/ t/ ~
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) h6 V" n o3 F5 ?) o3 `; t ;; give the turtles an initial speed+ [8 \. b h2 [+ p* N$ G; N
ask turtles [ set-car-speed ]
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: K) `) j! `+ G8 v+ z. w/ ` reset-ticks
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! q6 r' {' I% L3 ~* C;; Initialize the global variables to appropriate values
; H2 C0 V U5 W6 wto setup-globals4 L% ?3 }8 d. Z+ g% [$ ^
set current-light nobody ;; just for now, since there are no lights yet3 B( G8 _8 i1 a( A9 h
set phase 03 b5 r5 @* ~1 k5 @
set num-cars-stopped 0
8 L( s: C1 R" X1 { set grid-x-inc world-width / grid-size-x
' {7 u. a: |( `: K9 ` set grid-y-inc world-height / grid-size-y' e' p5 B2 f: m! u5 @& Y+ M d1 P
+ T2 C" R1 C) y( e( z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 z& U6 Z% Y ?* r: S/ S) Y/ d set acceleration 0.0991 {/ c# G' b. o6 B" }! w& J, P
end; j- J# L. N$ P7 \& a
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ V0 R7 l6 @9 P. ?* y$ g;; and initialize the traffic lights to one setting, ^& d6 C, h( L( ~' Q2 p- B
to setup-patches6 M# ~6 P- F' X
;; initialize the patch-owned variables and color the patches to a base-color+ j2 m. Y! `0 n# _
ask patches
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set intersection? false
J% s; a& N2 m' K7 a set auto? false* V% d8 D3 S; P* M- H
set green-light-up? true o9 N. S" q1 A& `7 Z8 A- k9 F
set my-row -1
! M( i" S1 C X2 h2 i* n( h set my-column -1- |- a; _ K! \% a$ f
set my-phase -19 L3 p: L- x; H) h# L/ t& g5 K
set pcolor brown + 3+ U3 z. L3 }' P8 C v/ [
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;; initialize the global variables that hold patch agentsets+ G( }7 e, i/ N/ ]7 C P! c) k/ C
set roads patches with
h" F$ k# P9 U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 Q. a/ m$ n4 K: r. I0 d: E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
F% l" t# K9 B; V- Y& i set intersections roads with
5 {# [: I1 d! f* W9 t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& E( |- j0 o! W0 |+ H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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8 M$ Y+ {4 L( S' M+ W ask roads [ set pcolor white ]
; b( \# }* M) R& {1 B setup-intersections' b! z8 u7 x4 ]9 [
end9 q' K% r5 t: R3 i& R1 ]; M
其中定义道路的句子,如下所示,是什么意思啊?
) A3 K* F% j# O2 W8 o& E$ F set roads patches with
5 @" O3 c& `6 p$ b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" v7 Y" V5 l) F) i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% y) p, g- @; F" i# U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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