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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。3 G* T1 z& q- v1 w. `8 g e
netlogo自带的social science--traffic grid这一例子当中,9 {) Y) d7 t+ }9 }8 J8 o8 i. ]3 k2 Z
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
6 Y0 @* x9 s" i$ ~ grid-y-inc ;; the amount of patches in between two roads in the y direction
; `( z6 r$ O/ ?! I( z: Z8 b acceleration ;; the constant that controls how much a car speeds up or slows down by if# F( x/ Z7 S8 ?- @% W" N! }
;; it is to accelerate or decelerate
: \. v0 j5 g( b3 Y+ c phase ;; keeps track of the phase
* u+ u/ D5 f9 c- T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( @+ C8 M% n. t$ r+ @$ O9 R4 O
current-light ;; the currently selected light
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;; patch agentsets* T7 a9 q; m+ F: s6 a! S0 [; g5 |
intersections ;; agentset containing the patches that are intersections
0 _' p4 L! {$ E roads ;; agentset containing the patches that are roads
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- x& H5 H4 E8 Y* A/ _$ Z- rturtles-own
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: j* b( @( V, u& Q- i! v0 V speed ;; the speed of the turtle; F* @) z# H, o6 H+ o. w
up-car? ;; true if the turtle moves downwards and false if it moves to the right$ _; i- P3 T1 L( G6 O5 L6 V
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
) E- P9 Z& y1 ?$ _6 x3 M) ]: c: E* I green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ q8 L) J d# U9 S x0 ]3 s ;; false for a non-intersection patches.% Z% n8 \5 \6 m/ m E
my-row ;; the row of the intersection counting from the upper left corner of the
. |4 g2 g p2 C8 v+ @8 }3 d ;; world. -1 for non-intersection patches.
`8 e; _8 m. P- K& g0 s* b- `# Y my-column ;; the column of the intersection counting from the upper left corner of the
6 N4 x4 x# Z0 L. D2 P ;; world. -1 for non-intersection patches.
$ q- m' m7 p ~, e" L4 b my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 u5 C- V3 c1 j+ Q+ O9 l4 J auto? ;; whether or not this intersection will switch automatically.
, B3 e$ b7 } Z. P+ U' r( w ;; false for non-intersection patches., I8 Z B. W) T8 t- I
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% z2 J3 a8 K3 n( w6 n" A/ n. l;;;;;;;;;;;;;;;;;;;;;;0 @; c- Y9 L* y D" _1 v/ U% z( @
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
/ V5 s8 S( o- R% O: ]7 c1 J;; Create num-cars of turtles if there are enough road patches for one turtle to! h+ U2 o* y6 ?- X, B$ I
;; be created per road patch. Set up the plots.
5 H( L9 `$ {5 D* w: c1 x+ k$ Y6 \to setup
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setup-globals: t+ B/ B1 U- D; _5 q9 [* u
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;; First we ask the patches to draw themselves and set up a few variables D+ g7 a/ W3 L2 F6 I6 Z
setup-patches
6 c( |* p7 j9 x" Y1 { U1 |, p* Y make-current one-of intersections
) L, |/ M4 K. }% ?& W R7 E+ j label-current# K# k. F9 d8 v
3 O- E. M5 `9 \0 n, x6 {7 t set-default-shape turtles "car"4 W& e8 X& q/ P4 W8 O- o9 f9 C: `' r
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if (num-cars > count roads)
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% ]/ I ^! Q3 F) e( b# \ user-message (word "There are too many cars for the amount of "
) M9 g8 v0 E; l( F2 V& {, X "road. Either increase the amount of roads "0 \# J+ w% M. Y& k/ d! W
"by increasing the GRID-SIZE-X or "
4 w8 m+ q) V6 A "GRID-SIZE-Y sliders, or decrease the "7 }: k! ^) g0 u" u. @* i; x, f+ I
"number of cars by lowering the NUMBER slider.\n"0 r, a3 A4 Z) k F
"The setup has stopped.")$ [& a- X7 G* O$ e. x" k
stop. e4 Z8 |* D! P! g+ S4 W0 g1 p
]
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" @) L. _$ F: _, T, @, ^( m- D5 F5 J ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 H) p& G; q4 P+ k2 m h1 j% J8 B crt num-cars; l2 U! K# s( F# a, F5 k, B1 q: n
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setup-cars+ m4 ^2 R+ o S! Y1 G8 P5 w) \
set-car-color
6 ~0 t) s3 ^1 U/ d, n- n record-data
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' O6 s3 b- b" m, M* ^! e$ n ;; give the turtles an initial speed8 U( L/ f3 u" Q0 k0 j E
ask turtles [ set-car-speed ]
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reset-ticks+ S; n, z# D' M# [, V
end d1 @6 q/ k' Y) ]/ X, N
+ o: M$ { G- n- y;; Initialize the global variables to appropriate values8 ?, H: n' i: K
to setup-globals
& T6 h- E0 y9 o2 b+ y$ ^ set current-light nobody ;; just for now, since there are no lights yet
& l+ d* t% S9 C G set phase 0
s6 m7 H8 H9 |2 J; N. \: l& T set num-cars-stopped 0
5 L' o% |3 G5 K set grid-x-inc world-width / grid-size-x3 }9 f! L& |( Y2 K Q* K
set grid-y-inc world-height / grid-size-y+ u8 @0 N( B. h* }. ?
, x, [4 M5 ?, N {1 D$ j9 E* d4 F ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 ]+ @. i3 v1 z* K! {1 d
set acceleration 0.099, k& i: G. ~% Y! O9 Z/ C* e
end i3 y: B" S: c; f, l7 X
! E' i! k' x* v+ x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 ?7 k9 i8 B! v5 a( X$ R& E$ P;; and initialize the traffic lights to one setting6 }/ U# d( b j2 i5 p8 o# y
to setup-patches* Q4 x6 L, R# T; }% u7 m
;; initialize the patch-owned variables and color the patches to a base-color7 w' P( k$ x: Y) O( m9 q
ask patches
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set intersection? false
g" b! d7 \- b; u6 C8 F9 K* L, f set auto? false; c5 G# B0 ^7 e4 i }/ Z8 U
set green-light-up? true
' C# \4 N/ P: \3 p- i) J/ C set my-row -1
( X7 D% F" j" R/ c4 r% D' G( @ set my-column -1% ]9 @* m! Z: m/ ~9 q1 ^2 z# s
set my-phase -12 i8 @3 u( h# E2 E: Q/ h
set pcolor brown + 34 {$ P9 F {$ x. b# C
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;; initialize the global variables that hold patch agentsets
. _# ]! k, P1 L set roads patches with
+ y6 N7 h7 X' a9 }# @, l h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! \4 C2 `% S3 u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ t9 J" L* S1 @; v, i& R7 i set intersections roads with
( v/ E0 R: Y9 P$ o4 L$ L. |. U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ S, d7 Q8 f& Z- h" t, {: b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; E* o& e X, E9 E ask roads [ set pcolor white ]: q1 P. |! |5 k, L8 H4 z x
setup-intersections5 M* v9 ]+ n0 ~4 G1 z+ O
end7 ?3 o- @5 P* f2 @/ E2 ~) d2 j
其中定义道路的句子,如下所示,是什么意思啊?
. S* m2 E* H. i set roads patches with
" I# C' L4 x% K, P& H- O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' E. F7 F5 D3 r8 X/ u6 R$ T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 _; j0 k# m8 c) l1 y! W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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