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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。
, t3 \' ]7 Y p: znetlogo自带的social science--traffic grid这一例子当中,
* ?1 H6 O7 C5 L( b4 Mglobals" W; L: Q6 h7 G4 ~9 R% M
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grid-x-inc ;; the amount of patches in between two roads in the x direction& i( Y `! W4 ]4 P t0 g/ Y8 o% |
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 l, w3 s! i! ?# K acceleration ;; the constant that controls how much a car speeds up or slows down by if
) V& f X' ?* C2 [ ;; it is to accelerate or decelerate1 r. C. V& ^! s( G
phase ;; keeps track of the phase0 b/ o( R; Y0 C, C5 X0 F
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# Z( A5 s2 n* V current-light ;; the currently selected light
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;; patch agentsets
7 j8 i* p6 C! x. M9 \$ t' n intersections ;; agentset containing the patches that are intersections
* x, v7 K4 w5 ] t( |0 A: f roads ;; agentset containing the patches that are roads
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6 n, h" O0 R- S, Y3 D9 j. u @turtles-own5 j. i/ i; |" b
[
' [) B7 `( @! X. Y/ n" { speed ;; the speed of the turtle4 w" r' [7 p2 u9 t" [$ V I
up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ s5 Z/ u$ K; a5 ]3 q! h wait-time ;; the amount of time since the last time a turtle has moved$ F2 ]- C+ H; a0 F2 T& X+ |
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7 @' }* ^* q; `- E. j" S& ?! fpatches-own
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" U1 d( ~& U, o9 d! P( W intersection? ;; true if the patch is at the intersection of two roads# B% q& y" z" y2 q2 o3 K
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 g% N4 a8 _$ }/ c ;; false for a non-intersection patches.
+ I" O5 J- E4 z0 r& }1 k6 z; |; G my-row ;; the row of the intersection counting from the upper left corner of the
" i3 J" L/ n. k9 C5 W* U ;; world. -1 for non-intersection patches.% y7 t: |/ m* A d O% N0 h
my-column ;; the column of the intersection counting from the upper left corner of the
6 B3 w# l s; ~& L2 G# B ;; world. -1 for non-intersection patches.
( b; w0 [2 A3 T8 ^ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; W5 _( Y% ~' d% l, } auto? ;; whether or not this intersection will switch automatically.+ c- b; M; ^! h( D
;; false for non-intersection patches." Q/ |3 q- H& I( y3 I
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/ A+ W1 V" V0 R* m4 p;;;;;;;;;;;;;;;;;;;;;;- X6 J# j. A- v* L! V
;; Setup Procedures ;;
2 x. N2 F# o) }: }4 g1 \;;;;;;;;;;;;;;;;;;;;;;1 j( ]7 w& w" Q: v, J, Y F; ~
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;; Initialize the display by giving the global and patch variables initial values.
9 \# e! p0 D7 k1 j. c;; Create num-cars of turtles if there are enough road patches for one turtle to: F. \2 s; Q* q: U
;; be created per road patch. Set up the plots.3 r9 q/ O2 B) } z2 ^4 K0 e. H0 C" C
to setup$ e2 ?; T0 \4 p$ P
ca
& R. X3 S. T' e, p setup-globals" A3 S v2 j" A" c1 s1 q2 m5 v
" N& e( N- p' ?( K ;; First we ask the patches to draw themselves and set up a few variables
5 V+ n0 m( U8 d* V( i: ? setup-patches
# F9 H5 k# ?5 Q( f: ? a make-current one-of intersections( ]4 l F4 h$ P
label-current
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7 V& [# E; X3 Z& v set-default-shape turtles "car"0 K" ?) [" ]* m2 F) u1 U2 d$ ?* y
4 [ f% p5 ]/ F, o0 C, K$ F; l if (num-cars > count roads); g; H: k' R3 M7 C+ E# C' K0 T
[
/ i0 [9 A+ n4 d4 q( k4 k user-message (word "There are too many cars for the amount of "
4 c$ ~' o* f+ F q7 e. \ "road. Either increase the amount of roads ". ~/ a! H% |6 }% D0 {9 z& l
"by increasing the GRID-SIZE-X or ") H* j" \- G2 E8 f6 c+ `* {7 b
"GRID-SIZE-Y sliders, or decrease the "
/ `4 Y+ M; f* Y) Z: e) J( w5 T "number of cars by lowering the NUMBER slider.\n". a& m- |; j/ S- A* p. ]5 R
"The setup has stopped.")
+ m2 v/ W$ N+ b; q9 O K" H stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
I: V' [" ]# p9 L crt num-cars9 E- A( H2 Y; h3 q( E! P0 l2 j
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setup-cars
% J) G2 g; V# S set-car-color
! F2 u \" F2 g1 F) `4 n' Z, Y record-data* `. ^: e# h% k& b
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$ T* z" u/ \% Z$ O! _ ;; give the turtles an initial speed
% F, v( l- v$ W/ F5 C ask turtles [ set-car-speed ]
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" n4 k2 r) C `; Q ` reset-ticks
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* g% t+ G" f9 @; x9 i! o2 M;; Initialize the global variables to appropriate values1 O6 v+ A1 e2 q- `- O6 E5 x9 f
to setup-globals3 [ w$ l2 u8 d, q7 C9 {
set current-light nobody ;; just for now, since there are no lights yet
* \2 t6 A2 a2 Q set phase 06 t, q8 N, T- t+ C% `. V
set num-cars-stopped 0
- t: i8 h6 r$ F9 C set grid-x-inc world-width / grid-size-x! h6 V) @! U) y7 E
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( I1 j+ D7 N8 l E; y: ]* K5 b2 n
set acceleration 0.099
' {0 k( T2 I2 }- Uend4 h6 C3 g" l2 v/ T
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! d$ M# [! J9 Q# a/ g;; and initialize the traffic lights to one setting
8 r' A; d$ [/ e% q( p6 Gto setup-patches
# W4 l! y% @/ h4 b, r: j! g; T ;; initialize the patch-owned variables and color the patches to a base-color @! T5 Q: J$ Q4 U' Y9 l
ask patches" p& L- m7 P1 B8 }; X8 I4 ^% ?: t6 h
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3 F! ^4 V* J/ F$ l8 {4 | set intersection? false
" I# K& M' T" D+ ^* K# p set auto? false8 p/ p& o( t- Z Y& C
set green-light-up? true( W7 L7 K6 L q3 E: G
set my-row -12 U# e3 @& d7 x% }
set my-column -18 Q5 w" Y8 \5 b) d! _7 n; a: J
set my-phase -1% B7 v0 K3 C9 [( U1 t8 {
set pcolor brown + 3/ N0 i9 d K0 n" n7 i) \5 v) n
]
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;; initialize the global variables that hold patch agentsets3 u2 M" t P) ]' c# q+ L3 W, L
set roads patches with
. O- y* L+ z6 L7 R( L* w1 @+ p6 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, J( c% Y% q+ [6 r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ F" J* Z+ u% E' z1 m; i4 y set intersections roads with; N* }5 b3 s4 F! e# x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 E2 S* P5 w7 ?( P+ _4 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: Y3 _$ R- ^- I
& y2 }% I5 A3 \: y& W6 t G ask roads [ set pcolor white ]
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end6 t, d. {2 k( v* K
其中定义道路的句子,如下所示,是什么意思啊?/ d$ O" a7 m0 a! w* s. K6 ~$ G
set roads patches with2 W5 M5 K3 [- p6 y' m5 D+ c' j$ q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ U$ n+ ?% S1 P) o3 R (floor((pycor + max-pycor) mod grid-y-inc) = 0)] M4 ~3 \( J, ~9 a% u* b4 p
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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