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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 V* W J1 p7 ]0 B' ?+ R9 H
netlogo自带的social science--traffic grid这一例子当中,' {6 B+ ?, F+ ]5 u
globals* ^ k/ V+ I$ {7 y4 F
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grid-x-inc ;; the amount of patches in between two roads in the x direction
: w0 u4 T9 |. h grid-y-inc ;; the amount of patches in between two roads in the y direction _: W/ D2 @$ y. D/ [" g y# t- v
acceleration ;; the constant that controls how much a car speeds up or slows down by if. D# ^8 [* W; G; y$ K: \9 f
;; it is to accelerate or decelerate
- B" V4 w! q0 |8 p phase ;; keeps track of the phase
$ H9 U8 f m4 T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 [5 z( ]) H# Q6 V1 B current-light ;; the currently selected light
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^& i$ z+ ?& X" b6 h ;; patch agentsets
; y& }9 P- Z$ n4 n( Y2 Y# Q2 j0 Z3 g: N intersections ;; agentset containing the patches that are intersections3 H. @8 A4 t5 i( y* {# {
roads ;; agentset containing the patches that are roads8 U" M: \, W! q) Q8 b) [5 C
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0 l9 j% e0 {- t1 ^) t3 `! eturtles-own$ `4 G* F0 h L1 r2 j3 p8 M
[
& i0 [* T d/ _* w, ]' U speed ;; the speed of the turtle3 L$ d5 G' r# V6 t
up-car? ;; true if the turtle moves downwards and false if it moves to the right; y" a: I( c8 H# w! G
wait-time ;; the amount of time since the last time a turtle has moved
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7 q7 {3 B" Y P2 O( Npatches-own
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* l7 j! q0 T8 w7 ~5 w6 {% m intersection? ;; true if the patch is at the intersection of two roads1 l' j- F9 k, }8 w) E% G
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! R/ H( j9 c0 i3 f" r0 w2 B* c ;; false for a non-intersection patches.5 _! C6 v; x" ?' a) z. s2 g0 [
my-row ;; the row of the intersection counting from the upper left corner of the
- i+ w" a* p6 }' I8 m, z( I4 F2 M ;; world. -1 for non-intersection patches.
4 p3 @& N) z9 K* X my-column ;; the column of the intersection counting from the upper left corner of the5 C* I7 K3 u& M9 m
;; world. -1 for non-intersection patches.2 g+ X+ _5 r9 A; y' c7 _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, o2 T- d) ^5 `1 ]; K auto? ;; whether or not this intersection will switch automatically.9 u1 \1 E& r5 I
;; false for non-intersection patches.+ A! ^: m' C0 w y: i0 J' o
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;;;;;;;;;;;;;;;;;;;;;;0 T! B7 n4 z* D/ W0 e
;; Setup Procedures ;;
* Y4 d" s5 Z: k" B. g% f9 m) i;;;;;;;;;;;;;;;;;;;;;;1 b1 b9 Y1 p5 i; f" L
/ i. V3 M( L3 o- Y, S( O0 z;; Initialize the display by giving the global and patch variables initial values.+ A l" H# k/ v+ i6 r& W
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 ~# b" i9 u7 Q0 K8 Y;; be created per road patch. Set up the plots.6 ^; z9 L9 G: {, \* i% `. N
to setup& g7 X9 k& }/ f3 `* {, w
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setup-globals
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9 A B0 w7 K# p$ Y: A0 L ;; First we ask the patches to draw themselves and set up a few variables
. m: a' g, p/ D* Z( {# G, U setup-patches9 m- B9 P( C! ~7 E* z: P1 i
make-current one-of intersections
" K: I7 Y7 m9 P* G label-current
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: o: M1 Y2 Q1 m3 N4 c set-default-shape turtles "car"
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& g( K. E$ d0 x" \ if (num-cars > count roads)! q$ l5 w; m6 y2 S" M/ s
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- e3 ^% I3 H* f user-message (word "There are too many cars for the amount of "
' A6 q0 X, k7 `& Q2 r "road. Either increase the amount of roads "9 U# d& o% j$ S6 ]
"by increasing the GRID-SIZE-X or "
# K9 D3 L n% ?: X! `7 K "GRID-SIZE-Y sliders, or decrease the "
( c( A' t5 R) ^7 Z; z "number of cars by lowering the NUMBER slider.\n"
, x0 P L0 T7 D z5 S "The setup has stopped.")
; M8 X8 a& R+ ~1 {4 @+ J stop
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4 A. T6 A. r6 R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( G! i( R. G, |: G crt num-cars/ d- T" w3 ?9 d
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setup-cars/ D) a K6 @$ |& A# Q
set-car-color/ }' I* v5 V J X- D( ?
record-data5 I: I) f* p1 A" X6 C w8 ~
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;; give the turtles an initial speed
' s" F9 @2 }; j( Z+ Q ask turtles [ set-car-speed ]
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reset-ticks
; | ^1 Z& B3 oend
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;; Initialize the global variables to appropriate values
, _) `$ D- \$ W" G7 \( w* Rto setup-globals
8 H6 I, B* T. `. }0 \8 Z$ j set current-light nobody ;; just for now, since there are no lights yet) A% V, f Z; z) H! N
set phase 06 `0 ]5 N w3 B( r' g
set num-cars-stopped 0
" @0 E' ]1 U9 S0 v3 ?4 S5 ] set grid-x-inc world-width / grid-size-x+ O' }1 X( y3 ]+ i3 ~; f b
set grid-y-inc world-height / grid-size-y
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5 s! n! t- a9 } A, f0 M" M8 | ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' D5 f- d' S! q8 @. [" `8 q, w
set acceleration 0.099
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0 x! _8 W: |2 p4 X;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ v9 d/ G" T9 I* @
;; and initialize the traffic lights to one setting: k; |8 c2 Y2 ?8 v& M# i
to setup-patches0 @4 C- M! f6 R4 _
;; initialize the patch-owned variables and color the patches to a base-color
- e8 j6 O0 Q m$ r" n ask patches3 Z8 z' s6 F5 t) O5 [# X
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" @: J* e* B8 o7 z( W set intersection? false9 ^- W6 Y% e8 W" e+ n) [9 ^. X
set auto? false
5 R6 n. w0 Z, X3 d0 T; ^& Z4 | set green-light-up? true2 m2 O! k' c) y- A; L3 O
set my-row -1
4 d" d2 {4 a9 L- z2 Y7 m( } set my-column -10 e- O" w% z7 R+ i9 z# [# F
set my-phase -1
3 d3 u/ v$ o: v% v! s. \ set pcolor brown + 3; h+ I- W( E4 r# g+ }
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;; initialize the global variables that hold patch agentsets
8 J/ C3 V5 _0 u set roads patches with! t" | g& F% u0 k3 P5 F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. ^5 A4 ~6 b8 Z+ v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- U" F7 m, y; K- e- x/ L3 O set intersections roads with
$ f. C* C; S- L. P! U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ u& k0 t! |7 i, k2 e+ D* V2 H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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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?
% w5 T" k3 x) i& a+ u9 [9 H1 W6 B# ` D set roads patches with
( [/ n) |* Q: B/ Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' ^. Y' ~# {0 w& ~' H5 v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 z0 `$ l- `( L- @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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