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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 B2 t3 h2 F5 pnetlogo自带的social science--traffic grid这一例子当中,
5 f; W; }+ Q' [+ Y; g0 Jglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction$ @' S/ L) l+ L
grid-y-inc ;; the amount of patches in between two roads in the y direction, {5 Y2 |% w/ n7 U
acceleration ;; the constant that controls how much a car speeds up or slows down by if1 P/ y, o; H: C. N
;; it is to accelerate or decelerate' q7 z; r6 U0 U" ?$ J" _ F
phase ;; keeps track of the phase
/ ~0 }% F+ X" R num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& t# b! x+ E9 q D8 M3 h
current-light ;; the currently selected light" ?" x M" U: v1 U/ @$ {
1 r" a7 L& y8 ~6 o ;; patch agentsets
: s4 _8 f- ?% }. ^2 w intersections ;; agentset containing the patches that are intersections
" `' Q. D( n+ Z4 c roads ;; agentset containing the patches that are roads
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turtles-own) K4 m+ v9 a$ Q; T& X& I
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speed ;; the speed of the turtle8 ~1 T D l& S+ Z
up-car? ;; true if the turtle moves downwards and false if it moves to the right4 E* E2 }% o9 Z: S
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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; V: d' C/ b5 D& U intersection? ;; true if the patch is at the intersection of two roads" x* T) B; O. x5 ?4 Q7 B V
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% Y' Q5 l" z9 h ;; false for a non-intersection patches.
. b0 S# L/ k2 n; Q6 {3 ^% I& ?" j my-row ;; the row of the intersection counting from the upper left corner of the
; V# B4 s$ Z. i0 P- b6 x ;; world. -1 for non-intersection patches.1 m" L' c: p/ _7 \: v3 p- y: M
my-column ;; the column of the intersection counting from the upper left corner of the
) X6 X+ k4 H' K ;; world. -1 for non-intersection patches.9 G( Q/ R- E! D! _( K) A, Q; o
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ T: x- V$ o2 D auto? ;; whether or not this intersection will switch automatically.
9 r8 r1 B7 q3 e6 C/ a% e ;; false for non-intersection patches.# m* v9 s: b4 `( [# Q
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;;;;;;;;;;;;;;;;;;;;;;
; L. \0 W& p6 w, E* K& f;; Setup Procedures ;;
2 ~4 N; D8 }$ {- i4 e$ I8 k;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.. R+ s2 ^" H( n- Z5 z. ]8 p
;; Create num-cars of turtles if there are enough road patches for one turtle to9 V! @$ u' s8 r% [+ `7 a" v
;; be created per road patch. Set up the plots.* b | m% o% v# c/ W. Y3 C' C4 n
to setup
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setup-globals" `! ~- s3 }2 u- \ k
5 l4 D3 i% s+ F$ u1 p8 r ;; First we ask the patches to draw themselves and set up a few variables6 g' F6 B0 q" V3 ?/ H2 g" z
setup-patches
% N0 P, M7 `+ f: S9 p make-current one-of intersections
Y$ V( [9 n, p; o, A, B label-current
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6 P2 x- U+ ]. o set-default-shape turtles "car"
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7 N3 j: N. Q5 P; ~" V" @8 Z if (num-cars > count roads)
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7 K+ L4 A1 M& T: Y user-message (word "There are too many cars for the amount of "
0 V) P: I$ d( u& K% c "road. Either increase the amount of roads "
5 X ~8 H& u% k4 g+ @4 ?4 K/ A "by increasing the GRID-SIZE-X or ". O: \) m6 r& D: a S K
"GRID-SIZE-Y sliders, or decrease the "( G% f l: Y# U2 u
"number of cars by lowering the NUMBER slider.\n"( w' w) q$ O! ?: d0 O) R( O7 ]
"The setup has stopped.")/ Q% k) _8 W. x1 y- ?7 q
stop
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! q: C+ m5 v8 F9 T3 R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# T; C4 J2 P! ]( B7 n# B7 u crt num-cars
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R; Z1 b% |( ^4 [! W setup-cars8 H; E- c' Y W+ K3 x
set-car-color: i7 R' J% y t+ z# z
record-data+ Y# q; J9 \. b: k
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8 g) B) `6 S) x ;; give the turtles an initial speed
7 Z9 }3 Z( C! H, X- |' U+ A7 t4 | ask turtles [ set-car-speed ]
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8 c `: l# v3 g/ a3 s: U1 d reset-ticks( s+ n G$ t N9 J4 a; ]- {' q
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' p) k! C; Q! F" q9 m! U' _;; Initialize the global variables to appropriate values. S8 a! t: |5 L+ P2 V' l
to setup-globals h5 f' B- [! j# S7 ^
set current-light nobody ;; just for now, since there are no lights yet
! E9 P3 a8 B* W) w5 j set phase 0
9 v; T5 j2 Z: u. _- ]+ j set num-cars-stopped 0
8 q0 O, P* W% f1 V# x5 S- f8 n$ Q set grid-x-inc world-width / grid-size-x* n0 H( r/ K3 f- y
set grid-y-inc world-height / grid-size-y
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4 V5 b1 K3 N2 Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: F" w3 C8 I) K% N; j# l5 G; e1 e
set acceleration 0.099 I3 M# v, P1 x' w3 a/ l- ]
end
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) k; d5 s% N* s+ H- E: Q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 s5 {/ ^, Y' k& h( {& S
;; and initialize the traffic lights to one setting" F- K. J8 i, C/ e
to setup-patches
$ j5 a0 C" Z X3 G4 G ;; initialize the patch-owned variables and color the patches to a base-color# i9 N4 V: A7 Q
ask patches
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set intersection? false
8 h- K! t4 P2 w& }& S set auto? false# E- |8 a$ N* S6 c4 h/ j& ~
set green-light-up? true
8 l, q- h& }( P' ?) R set my-row -18 `3 |8 }& m* r( k) R
set my-column -1# k4 o* {' G$ L6 {
set my-phase -12 w3 }3 V7 y/ C! H
set pcolor brown + 30 A" K, C j' i! r
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;; initialize the global variables that hold patch agentsets
" B b, a' W G0 o set roads patches with
5 N8 [, P3 H5 h# g6 [: u9 D0 ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 G2 G& Z8 N+ S5 _* A+ p. L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 R- O5 T# G V& b0 {
set intersections roads with
5 f/ M: D) K1 Z, k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 w- [4 y; \. u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 V, ]# p7 L' T& n+ |: v1 m8 p
$ {- m; m0 }- Y: V3 K; z2 P 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?
9 Y+ T. c8 ?$ o5 s* u9 v5 ` set roads patches with
. ~% t# [( f9 J0 L" p2 C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# E0 q* K" L- K% ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 @1 k3 I1 n B# _
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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