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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。
0 ?% w! y; h: N3 Q! W8 I" unetlogo自带的social science--traffic grid这一例子当中,' w$ T6 n* z& t: }5 c b2 y c
globals" f, n9 J# _- }; k6 n% H
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 A+ E; q0 R4 |+ v+ k
grid-y-inc ;; the amount of patches in between two roads in the y direction8 ?! c4 n: @" [7 `
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 z I, o( l) \4 K; { ;; it is to accelerate or decelerate6 ^" O# ]) K( Z
phase ;; keeps track of the phase# B! \9 D! R" w& U& K) l0 s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 v: N2 ` u% F
current-light ;; the currently selected light
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4 z* R7 i, X, }+ ^5 u, `9 z ;; patch agentsets
2 N" g* B+ Z' _ c/ ? intersections ;; agentset containing the patches that are intersections
9 {( a9 w& }" X; I6 Q* ^4 q roads ;; agentset containing the patches that are roads9 @9 [" Y% W) L; C6 c; }/ P/ c/ n
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~% {, a- o6 D% L/ _: }turtles-own
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speed ;; the speed of the turtle
- f4 P6 V, J* R1 w% d1 p up-car? ;; true if the turtle moves downwards and false if it moves to the right9 c3 Q9 {* A6 y: ^. V$ Q" ?% @3 ?
wait-time ;; the amount of time since the last time a turtle has moved3 Z* T j# b( b3 T
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# s1 {6 H! @1 E! \6 Ypatches-own
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$ T0 x9 N2 u8 c1 H8 J intersection? ;; true if the patch is at the intersection of two roads
. Q$ K# H* L+ O# d5 R( k" j green-light-up? ;; true if the green light is above the intersection. otherwise, false.: D: I. o1 M4 H2 U1 q* r
;; false for a non-intersection patches.) U3 o& ~ A+ S# r% u- S% I
my-row ;; the row of the intersection counting from the upper left corner of the
$ Q$ a" R( L0 Z' W/ \' W, O. D ;; world. -1 for non-intersection patches.
& S* a. L$ Y" O, F my-column ;; the column of the intersection counting from the upper left corner of the
8 u* V. e8 j- W) T& \4 S ;; world. -1 for non-intersection patches.
" W& X0 A: w- C my-phase ;; the phase for the intersection. -1 for non-intersection patches.. Z+ P" H/ D g# H3 e
auto? ;; whether or not this intersection will switch automatically.
3 b/ q, m3 L m8 _0 [ W$ L ;; false for non-intersection patches.0 U* t; C$ f, Z3 Q& i( O# z
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;;;;;;;;;;;;;;;;;;;;;;: M/ o' }+ W1 x, T0 s
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.. h# |! l! w/ j. g. h
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 V& ]7 [4 G6 Q, Y: Y% {;; be created per road patch. Set up the plots.
% s8 h: @; C1 \* G/ o+ d$ hto setup
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" M( e5 _5 L, H! z4 f3 E0 A setup-globals9 B1 K1 T/ z( @! K. Z- {1 s
Y3 t6 t# b, v6 u ;; First we ask the patches to draw themselves and set up a few variables# w& ~6 D; W1 l, y b
setup-patches
4 d9 H( u7 I5 G& ]7 N: O: H. r make-current one-of intersections
* t; e7 p. X) {& `2 r label-current
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set-default-shape turtles "car"
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0 {$ j. T- C/ |3 I; B* w if (num-cars > count roads)
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! h. b" K. D1 @' s- k user-message (word "There are too many cars for the amount of "* E( r" ~3 r, L. g- e! q
"road. Either increase the amount of roads "7 X) U3 s; i2 q" ^5 V3 `
"by increasing the GRID-SIZE-X or "2 H5 q' i- v2 R7 E, H& o, U" q
"GRID-SIZE-Y sliders, or decrease the "
# ?3 T& J& } \ "number of cars by lowering the NUMBER slider.\n", P1 x% T0 ?6 G. L# e. j
"The setup has stopped.")9 q9 K! \0 r+ U
stop8 T9 \/ X" R6 k! a& S2 I
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# g; n6 x. ]" d2 [, O2 T ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ p$ O0 r- v6 Y4 |6 w) U$ k crt num-cars, K" d$ z7 l8 N9 ~/ F
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9 P: E0 }3 M7 A1 D setup-cars- d% X! g& U" a* }. V
set-car-color- G0 A8 s' T8 h) T( Q! ` U
record-data$ }1 ^3 {" {5 X* d I6 r
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;; give the turtles an initial speed
0 F8 ~$ S, w$ v; ~, ?6 Y# N& o; t ask turtles [ set-car-speed ]! t( @9 R5 c. ?6 C0 G& D
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reset-ticks
; q# l* A1 w1 I$ ~end
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# X1 M) x9 s% U3 T# C;; Initialize the global variables to appropriate values$ o/ E) ~4 }& Y6 ~* [$ [" I" f
to setup-globals! a- {$ k9 K4 l
set current-light nobody ;; just for now, since there are no lights yet% h* F0 v" L: ^& @; u8 Z
set phase 0
: U8 N6 p5 D7 }. F( Y set num-cars-stopped 07 n9 _9 G4 U; x1 i
set grid-x-inc world-width / grid-size-x% J: ^0 K2 u. F/ [8 T" M* h
set grid-y-inc world-height / grid-size-y* |$ H/ x' ]5 W5 N7 V5 D5 y5 R
& |4 A; ?" @3 [" A. Q: y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 p) w- z* ~) I* E2 W u set acceleration 0.0991 ~. U# H; _, _' D$ [# T! [- B
end
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' b8 l: q5 U+ G" l; z) w" {;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 ? u# R5 l+ u4 H
;; and initialize the traffic lights to one setting( j1 Z+ W1 ~- e' K' _
to setup-patches+ @ l ?8 Y% f5 d+ @
;; initialize the patch-owned variables and color the patches to a base-color2 w+ ?# r! H& ?, c4 _' {# m
ask patches
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@" K8 D4 E0 r# E' U) V/ |0 a set intersection? false& T- q: e0 ~( V) g$ P/ u
set auto? false6 N& V7 {, d+ ~: n
set green-light-up? true% L3 Q' D, o* e8 U+ T
set my-row -1
! u# O: ^; K& r3 b/ U/ j set my-column -18 e1 q& I W! N5 u' z" E8 o4 A3 `
set my-phase -12 p. ~6 Q- g. T7 B1 M& ?
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
) m; ]0 s$ o. X- K! q \/ K set roads patches with) t$ a( J2 h n1 u# m) R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ b6 j# k# B: a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 l1 P2 D3 I' M* p
set intersections roads with
# L6 E4 i) m, e' t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 Z Q7 H2 M L( M1 a$ o7 a" a- K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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0 i$ X" j$ a$ f+ @0 y ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
( u5 `6 `) q) L3 Q5 s set roads patches with
5 I, K+ I' n; Y3 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 [1 {& `9 y( v. D# z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. o$ M! R- ~# ^! s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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