|
|
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。
4 a+ |0 l: g. Tnetlogo自带的social science--traffic grid这一例子当中,# z4 ?( v8 j" s. C- y1 g
globals# j! a- x. ?5 W& m# {
[% n& ` `0 ~0 F$ O
grid-x-inc ;; the amount of patches in between two roads in the x direction
/ ~: x; ?/ |# m0 P/ v grid-y-inc ;; the amount of patches in between two roads in the y direction
; [+ Z1 f. [( z' ?: x; i acceleration ;; the constant that controls how much a car speeds up or slows down by if
- ^. s d) ^' s4 | ;; it is to accelerate or decelerate+ I* l% J% f( p
phase ;; keeps track of the phase' e' B/ L+ w6 F r" E/ z0 ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ \2 q% Z$ Q$ o+ J) m, ]% J2 a3 I current-light ;; the currently selected light1 [& J3 K. X7 p3 H. z+ K! X2 k
3 X$ m3 f! M* X: n" V
;; patch agentsets
) }% N! ]* C: y8 X' I intersections ;; agentset containing the patches that are intersections6 J3 a" x+ j& v
roads ;; agentset containing the patches that are roads
* w( |+ a( l" y]" k* G3 ^$ ~4 j' }# z
0 B1 f9 s) Q( A6 j" R0 [: {
turtles-own1 i3 y! D2 n8 t1 D7 H2 |
[/ `; f! i$ b8 s) z
speed ;; the speed of the turtle
3 `* U B$ M. A$ K3 f x* W! H2 P3 B+ C) G up-car? ;; true if the turtle moves downwards and false if it moves to the right
& F7 X: \4 X" H7 v0 N wait-time ;; the amount of time since the last time a turtle has moved
6 c) V6 e$ [/ ~ [$ R' W]) m8 u! D& G( H' C P6 O
0 C; g/ C$ j$ F- W) z* Dpatches-own
. A. a3 O. F+ |4 Y# f1 u[
) o2 ?& S9 f5 n6 X+ M2 M- i. y* D intersection? ;; true if the patch is at the intersection of two roads
! D$ E8 }9 ]% X& {. M+ a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 R# u0 Y: z) x, d ;; false for a non-intersection patches.3 u# ^2 @/ ^# ^6 E: N+ O! E8 d8 h# Y% r
my-row ;; the row of the intersection counting from the upper left corner of the
4 W& J( R1 \. G' o2 m% _$ s2 y ;; world. -1 for non-intersection patches.: o- }( K9 G" J' n
my-column ;; the column of the intersection counting from the upper left corner of the
p" k @% P! z/ r- \ ;; world. -1 for non-intersection patches.( G2 |; x6 ^8 _; h) ^! G2 z8 i# Q
my-phase ;; the phase for the intersection. -1 for non-intersection patches.( h0 d/ R, Q; @7 ?1 B( C
auto? ;; whether or not this intersection will switch automatically.
' p4 e9 [: b: v* U0 y ;; false for non-intersection patches.
8 o* l* h0 k# W- ]- {" F]/ L* j7 {. A4 p' x* [/ y
* _4 f" P: ^$ K& \% ~5 a6 c
/ N1 I- w7 @: r9 z" E;;;;;;;;;;;;;;;;;;;;;;2 j+ y, J! N3 M
;; Setup Procedures ;;4 R) W% Q' _/ _; X
;;;;;;;;;;;;;;;;;;;;;;" U" A( V4 U/ v/ W
3 z. [+ p7 s! i- y% m# s
;; Initialize the display by giving the global and patch variables initial values.# n9 b, x. z. M; e* G
;; Create num-cars of turtles if there are enough road patches for one turtle to+ h. j& e8 g. @9 I- o; d
;; be created per road patch. Set up the plots.0 x( M3 _/ _2 ^9 ^% F% @5 V U
to setup
9 k f2 i9 `( S) G' r/ r ca& y" W. @3 ~" i( G, y$ f
setup-globals
' L+ R! D$ h* C% Q
( }' ^' c4 @* O1 \$ b* X1 Z ;; First we ask the patches to draw themselves and set up a few variables
2 |5 C6 f, R( ] setup-patches
' ?, s( I% ~3 _: K make-current one-of intersections. C6 ?% O1 g. y* c- p
label-current, n( Z: L* `% E9 Y9 T
0 c4 n& c; Z* J; ^% A set-default-shape turtles "car"
, A7 p1 T) F8 y' i
1 g @4 }1 m% S( g if (num-cars > count roads)$ m# I. r5 t3 Y
[
6 K4 |' H% ~. n, a; i2 Y s user-message (word "There are too many cars for the amount of "
7 X: \8 U2 F4 W4 Q! b2 x "road. Either increase the amount of roads "* B9 E" ?- U# ]5 ], W# p. B% B/ F
"by increasing the GRID-SIZE-X or "
; w1 |7 }3 v& n% L "GRID-SIZE-Y sliders, or decrease the "9 X+ ]6 h/ q# T
"number of cars by lowering the NUMBER slider.\n"4 ]$ N' R8 t6 _ @+ p) V
"The setup has stopped.")2 I5 p/ ], H; D7 s A8 p7 \1 ]) J
stop
9 b% u$ m9 g7 m& u& f7 }2 k ], q" b0 x7 b! v
2 X. W6 o! Z8 ~; H6 w& J) v# G ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* s! |; ?: k* O; s; N) s" M* f2 q! } crt num-cars
5 h. A7 `/ b+ `3 t- D' G) G1 ~ [
" w0 j) g! k5 k* L setup-cars
1 Y0 l5 }; x9 q set-car-color
: b' i+ [0 i6 V5 A! e( O record-data
7 }' z4 P, G) [' d. } ]
C3 Q( G& s ?& z( D: |5 m! y8 D8 z- c" Y9 ~2 L3 X# r* R: p5 s) [3 r, v
;; give the turtles an initial speed
/ g4 g- |$ h1 V$ V2 b ask turtles [ set-car-speed ]
) {$ z8 n- b9 t: r% v
' z8 N" d% }7 H: W* s( f reset-ticks
4 `3 y! v" {: e* hend' N- S3 H2 ~4 h( v5 D, L
% z* i$ N0 q5 Q" s4 d, ~. V
;; Initialize the global variables to appropriate values8 m+ A+ b, e i, j1 `
to setup-globals+ X6 k. @5 J% x% ?+ S8 h
set current-light nobody ;; just for now, since there are no lights yet
; F- c5 P. ^3 c% D2 }" N L B9 N set phase 09 t" g# z; O9 ^& ^ E4 _3 S
set num-cars-stopped 08 G, ?% e- w8 h$ G% n; s, \) ~
set grid-x-inc world-width / grid-size-x
' f3 g7 n- }) n set grid-y-inc world-height / grid-size-y
5 V+ ~6 Y5 T* g# U9 X$ O$ x6 S4 F2 }
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. t5 {9 }: E! o9 Q0 c set acceleration 0.099
3 K# {# ?3 z# c7 v" Send1 E- J1 n3 _1 y9 n% O6 t
2 e$ E; \9 p/ g) a: y" W; w
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 p! } U; H% H Z$ O) d/ q
;; and initialize the traffic lights to one setting' ]6 u5 c5 n8 `3 B) P. ~' r
to setup-patches
~8 |, q$ R# E ;; initialize the patch-owned variables and color the patches to a base-color$ n0 @% e* i v) O
ask patches
' F7 \0 `, ]7 b" L' Y* D1 V& h# |+ x& ] [
4 u6 C% X' P- W9 e5 E set intersection? false
% l0 P) t+ R. B: I2 ^7 v( P set auto? false) y* p0 J9 G. z- c; h
set green-light-up? true, M' ^7 U5 e Z+ ^8 @- v
set my-row -1/ Q P* j3 J& }- g7 r
set my-column -1! W+ m6 M N) N& s3 G: y& s
set my-phase -1! I7 H3 a- m1 @) a$ x
set pcolor brown + 3
" r" ]' `" P, Q1 J& Y2 V ] \+ @8 z& X% v$ H' Q6 s9 r4 U
# e+ y, v4 k$ x- x
;; initialize the global variables that hold patch agentsets/ ^1 P4 ?' g' w
set roads patches with- E( y7 Z$ U1 r. w" D- _+ s' }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% k8 L6 R" }6 h& |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: }; Q [% _6 f( G+ o( |
set intersections roads with
5 c1 |/ n$ D6 ?0 E; w6 i+ y$ H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ y6 T9 `4 q* f; a2 w- O
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! @. u4 c% o: z# `9 k" O
8 q+ y8 F4 v! E% H: C3 J4 C+ x ask roads [ set pcolor white ]
; Y' i7 y1 s( X setup-intersections- e( I) O8 I- o+ A$ f9 [
end
) s+ _$ X' q& `8 Y- a其中定义道路的句子,如下所示,是什么意思啊?2 G- n! K# N( A
set roads patches with
& P& s$ `) P0 L4 S( n1 e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& x* V" i3 H; i2 X& k, M/ V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
e, S$ C ?' j2 j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? |
|