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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( b9 B3 K7 z% y* [- m0 W. anetlogo自带的social science--traffic grid这一例子当中,! }* d+ ~+ s' u8 b' m- `8 w9 ?
globals' F* r1 O( R" [% ~4 v8 J( I
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. L* l* M0 W1 _9 m grid-x-inc ;; the amount of patches in between two roads in the x direction+ L% V# z0 w0 i/ _% Z6 i& n0 S
grid-y-inc ;; the amount of patches in between two roads in the y direction4 Q. Q7 _5 `- ?6 H" e
acceleration ;; the constant that controls how much a car speeds up or slows down by if
6 I( V0 S9 y# G+ Z1 W ;; it is to accelerate or decelerate: W3 V5 H- N/ s5 K# f2 E* K! @
phase ;; keeps track of the phase
& K+ F8 U% Y( Q- ^2 f8 r num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: |* d7 x6 v$ O- ]/ U current-light ;; the currently selected light6 \1 g( N# j$ H1 d2 Y
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;; patch agentsets
# d1 U3 Y- k4 @; o. u8 k% g$ j. [ intersections ;; agentset containing the patches that are intersections
' ?' p9 I9 h; { roads ;; agentset containing the patches that are roads# u% R. R2 N& C2 Z/ p3 u' e
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) T/ R# }, h( G7 V/ Eturtles-own
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2 ^, j( u, W9 k6 g& c6 h speed ;; the speed of the turtle2 F. B ^& G) s. M
up-car? ;; true if the turtle moves downwards and false if it moves to the right
: ^0 B1 f. L" m: K wait-time ;; the amount of time since the last time a turtle has moved
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) w% M6 U) z8 c$ r. B, i- r8 Jpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
0 _0 a$ Q8 w k0 z( @) b0 Y7 X green-light-up? ;; true if the green light is above the intersection. otherwise, false.& D" ~' p0 c7 _8 J& f
;; false for a non-intersection patches.
N* A. o. v- o* t my-row ;; the row of the intersection counting from the upper left corner of the
9 N4 t) i# E3 s# u ;; world. -1 for non-intersection patches.
8 N4 h( U" u) h: } my-column ;; the column of the intersection counting from the upper left corner of the# R8 U/ p# y( D5 l) B& m6 A3 ]# q
;; world. -1 for non-intersection patches.$ \0 z' i- r2 d0 P' N% c3 V! o2 u
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- y4 o2 t! ?0 ^: U1 e$ B: ?0 H2 P auto? ;; whether or not this intersection will switch automatically.
# F* H0 C0 T& c: e ^: S ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;0 T! W& S0 Z% x
;; Setup Procedures ;;, r, }" \# D; C ^4 ?% u
;;;;;;;;;;;;;;;;;;;;;;2 U- q/ P3 X+ Y1 ]; k, I0 J
( K! [+ q! v7 D" Y: y9 N; W% j;; Initialize the display by giving the global and patch variables initial values.; U5 v2 D0 |. x& x
;; Create num-cars of turtles if there are enough road patches for one turtle to# L" `! v$ Q! u' k/ D7 s3 C
;; be created per road patch. Set up the plots./ I$ y x$ [3 L$ R- B
to setup
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8 C4 x% U: n" `1 k/ K setup-globals
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2 O# ?% u+ j; u9 S, j. P! v/ B- ?5 ^ ;; First we ask the patches to draw themselves and set up a few variables
2 y: G) g/ t. N9 R% A' } } setup-patches4 C' \/ H) K6 u# v7 j2 u
make-current one-of intersections
3 P. i1 b9 ~: o# B label-current+ g7 N- N/ m) ]+ }# r
* E+ ?0 b8 {, S& ^2 D( e set-default-shape turtles "car"# U' D" Y! B9 T% H7 N. @$ {
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if (num-cars > count roads)
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$ I1 q- t8 b) i/ e4 D! N user-message (word "There are too many cars for the amount of "
' `0 @% ^' e# S& c" H, g# L "road. Either increase the amount of roads "
/ z4 h$ S: A5 \# {! C2 @, C+ p2 j "by increasing the GRID-SIZE-X or "
( E" u% i" z3 s& L. O4 H/ ] "GRID-SIZE-Y sliders, or decrease the "( R; C. q$ o& Y
"number of cars by lowering the NUMBER slider.\n"
2 ~9 u; l* V3 o7 R# a "The setup has stopped.")' x4 B2 z; t7 {- m4 Y: H4 G
stop5 S* L4 m! m* R! Q! l" u
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# x" f- @+ x- p6 x ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" w3 ^5 M e0 N0 D( r) }+ j. g crt num-cars9 ~$ ]. O. @$ q, _/ f7 f4 O
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setup-cars- J" X2 H z3 s" b3 T. `
set-car-color0 a! ]* r5 z$ f0 g5 t
record-data8 d2 p# [) e/ e9 l6 s$ z A; M
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* y8 o& e( c8 F& v( O3 C ;; give the turtles an initial speed* e2 ?5 @5 g1 z$ ~
ask turtles [ set-car-speed ]
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+ O/ \# `& K) L" O6 Y4 _ reset-ticks
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;; Initialize the global variables to appropriate values
7 s4 h5 s+ Q; b% k ]1 dto setup-globals
. I5 C9 G! {; d8 t- B set current-light nobody ;; just for now, since there are no lights yet
. Z6 x0 n7 A/ }2 w, a: W" N set phase 0/ c% l" J; z0 Z Z+ _2 Q. |
set num-cars-stopped 0% `: h, T; Z+ G6 G( R, W. v
set grid-x-inc world-width / grid-size-x+ y5 C8 v3 y. j* o# ~6 V) h
set grid-y-inc world-height / grid-size-y2 W3 {( C0 H6 }6 z
2 E) V" X9 K! k& J/ d ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ X& `! n! x( x a9 Y% z& e. ]$ ?
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& F6 y% d# h+ N% M8 j( i
;; and initialize the traffic lights to one setting% e* Y1 g4 V: ?8 U
to setup-patches+ p1 x# u& _6 S6 N
;; initialize the patch-owned variables and color the patches to a base-color$ I+ S% g3 X, u7 W0 }% s0 U) E
ask patches
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set intersection? false
2 t& B) g$ {3 L7 R6 x1 h set auto? false
( l; k0 R+ I# d, E) Z: y4 K) o set green-light-up? true
: H- @/ y k* M( j- l set my-row -1
4 o5 }1 }' I- I; d# g set my-column -1
3 I% k2 U- Q; I. c/ D set my-phase -1
. V3 |" q; g1 Y/ C/ q/ } set pcolor brown + 3; h; ^, L$ s: K8 d+ l
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1 @7 o1 T$ \* c+ H" ^ ;; initialize the global variables that hold patch agentsets3 ?) n% e9 s+ L: {' D8 I- W( Q* G
set roads patches with
: C9 w' ]$ Z9 p: n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* N1 O& s7 D k6 {1 m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% B( r2 [4 \! r! d/ [, s k set intersections roads with |7 ]8 Q. c5 J9 O' T3 x# m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# W1 a+ h9 y7 E3 p# y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]( z) F" v* W, Y7 Z, K( J
setup-intersections* }! P; f) r+ v
end5 w+ i) W+ } o' m
其中定义道路的句子,如下所示,是什么意思啊?
7 F, u) t# _0 t/ T* z set roads patches with
0 \6 e8 G+ H3 {+ `4 ]- y: E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' o3 t# [( m& v4 h+ e4 h3 L& U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; e4 q- H6 I( _$ x, l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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