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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。
a6 }3 P. Y) h. c1 o3 Qnetlogo自带的social science--traffic grid这一例子当中,
7 }1 m- x7 e- V% \+ c2 q7 ^globals
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% E. v* @8 d$ s1 A8 m9 o grid-x-inc ;; the amount of patches in between two roads in the x direction6 |+ z8 p4 s& |5 v! V% S; V$ ~' L
grid-y-inc ;; the amount of patches in between two roads in the y direction3 v. A/ i5 x+ c' K
acceleration ;; the constant that controls how much a car speeds up or slows down by if
- r* p* Y( p% l5 |: y. G ;; it is to accelerate or decelerate
0 u0 Q+ W8 l9 p2 u phase ;; keeps track of the phase
* c- N- ^7 O' K5 J( o) N) j( k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 Y& k; V% s" m; \- W0 N current-light ;; the currently selected light. V$ c& e- h: K3 ^8 X
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;; patch agentsets3 U4 I! N$ r) q2 a. D: l' v# Q
intersections ;; agentset containing the patches that are intersections
1 v$ e) o% z2 k( v$ W4 x C0 X roads ;; agentset containing the patches that are roads* Z& u$ q: U& b/ L! f/ |
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turtles-own" m4 r! U& {) t' c/ Q% b
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( ^* [* I; `) P, q7 v, N speed ;; the speed of the turtle
7 H p/ w- ?5 Y" R @& x$ | up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 R) u' E) K. r4 q* x 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% T) G- H9 r! ^! ?; p( P1 `
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' B% a0 {+ w! u7 T ;; false for a non-intersection patches., N7 ~ J" Q: E( l% t# p/ m. z
my-row ;; the row of the intersection counting from the upper left corner of the
7 `& N b' G% d( q# L( o ;; world. -1 for non-intersection patches.# Q" |) `0 r2 \; b# a' Z8 o
my-column ;; the column of the intersection counting from the upper left corner of the
) H- {' E# h5 C: N) q/ S+ n$ j ;; world. -1 for non-intersection patches.( `+ B4 @. h- E4 |% l
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 P+ o2 b1 d: k0 w9 O3 y auto? ;; whether or not this intersection will switch automatically.- w, l5 L C p: O9 e: p
;; false for non-intersection patches.
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4 d8 o' m' ~; M @8 X7 m;;;;;;;;;;;;;;;;;;;;;;* p9 S# H O" p# J7 [- F2 T
;; Setup Procedures ;;$ Y8 A$ X2 D+ X( r1 d: U9 g
;;;;;;;;;;;;;;;;;;;;;;0 r3 R ]6 K) \: H$ O
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;; Initialize the display by giving the global and patch variables initial values., U& K/ M P l( v0 l) G2 ]7 u
;; Create num-cars of turtles if there are enough road patches for one turtle to, u `9 e {3 t$ c
;; be created per road patch. Set up the plots.
6 ~9 }6 I6 A s" k- c) a' X# zto setup
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setup-globals$ d: }. @6 ?& `' U
9 N" _" e% \) `0 l5 f7 ^0 A ;; First we ask the patches to draw themselves and set up a few variables5 m P( m5 l6 u7 @; ^0 H
setup-patches+ H' ~) p0 k! h/ \$ U7 l$ n
make-current one-of intersections2 H* a7 O* y0 s+ L. m' Y( i
label-current
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1 k4 T: K6 f& Y' }& ~; c8 R set-default-shape turtles "car"
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if (num-cars > count roads)
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3 Z' a! K! }% G$ x- }. X" S user-message (word "There are too many cars for the amount of " U! p- G$ P4 P
"road. Either increase the amount of roads "
' O5 [7 t6 Q& Y1 ?# @ "by increasing the GRID-SIZE-X or "$ F5 W$ Q% v# }
"GRID-SIZE-Y sliders, or decrease the "% b* l* j. }2 S( p7 a& S0 x
"number of cars by lowering the NUMBER slider.\n" H/ ^ l9 H' W
"The setup has stopped.")
* N6 N3 K3 |8 u4 L$ C0 N stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color9 a+ n; ]7 p+ q, p7 n5 U, y5 e
crt num-cars
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$ I- X# q1 b; j setup-cars9 _0 e# F' B; Q, L/ D! I* C7 m
set-car-color0 b, C8 Q/ b9 ~- Q2 ]* p1 o
record-data
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;; give the turtles an initial speed
% s- f7 y% N3 k4 C7 f8 Q ask turtles [ set-car-speed ]
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4 {* ^( j! A( G" h" w4 m6 g/ F reset-ticks7 \0 S$ d4 O. N: y7 A" k5 @
end
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+ J3 B: _1 d. O4 y;; Initialize the global variables to appropriate values4 c* x& |1 |% J5 d- m
to setup-globals
; v3 {7 g5 P" N n4 }5 ^ set current-light nobody ;; just for now, since there are no lights yet2 g* w) k8 ?& t& a
set phase 0 _! k9 @4 K3 x Y& J% t$ |
set num-cars-stopped 0; A, R2 {" R/ {/ n u5 ]1 C6 o
set grid-x-inc world-width / grid-size-x9 f- C* `7 {4 v3 G
set grid-y-inc world-height / grid-size-y/ O! c+ R# a; T; u2 M/ O5 @! K
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" E" a9 S* s2 A" A% e set acceleration 0.099' E! S- |& H: ^( \5 C) z5 ~3 A
end/ a+ }* G8 ?. F4 @$ F
7 e+ G3 K( a* f2 C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
S& @0 T8 U" ]3 H. B;; and initialize the traffic lights to one setting/ T/ F1 o: X( `" T3 f( M9 O4 y
to setup-patches
# j8 Y, T0 k3 i7 Z8 h) X3 v ;; initialize the patch-owned variables and color the patches to a base-color
0 F3 P+ c" h0 D" Z! A) M ask patches
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set intersection? false
: a1 w0 }$ n0 I8 Z( o: r$ t set auto? false
0 r% Q! j' j/ s) P4 V3 i8 j set green-light-up? true
+ ~( z9 R4 j/ t7 a; z* t set my-row -1
# H" C" q: ^* \ set my-column -1/ {4 D* l" O) }% g$ T6 n5 T
set my-phase -1/ i8 ~. a: O5 L
set pcolor brown + 3
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* `- U/ g- y7 S+ ?4 J ;; initialize the global variables that hold patch agentsets
% O Y( \: j5 V( V. Y3 j; E set roads patches with6 h* d( \/ N5 _* U% f# l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ d1 Z1 @1 } w$ y4 D% Y/ ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* @2 B* V d8 ]) T( b) P set intersections roads with
; B2 `# Z/ \9 q! O" H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and i# P( n$ U. I. S& k- O
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! w Z) f! k5 P
5 e$ V3 v. D& l) y) d7 t7 i+ n! i1 D ask roads [ set pcolor white ]( h& V1 t* Q! P0 G6 e$ \% |+ g$ E3 l* I
setup-intersections/ g; K3 U; V5 ]) B! T
end
6 @8 q8 v& [- @5 |' e其中定义道路的句子,如下所示,是什么意思啊?
$ S& m4 T: a- e4 { set roads patches with
" T% u8 x6 }( H: _: E0 o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( h! C6 v* \8 O7 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 m. {+ D* B% @ x; s) g2 I
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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