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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。
7 U6 ~0 o3 R+ ~% _/ vnetlogo自带的social science--traffic grid这一例子当中,
* H* _! p+ h% d4 ~globals4 @) q2 V6 |8 k
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# S5 m5 S! F I grid-x-inc ;; the amount of patches in between two roads in the x direction
; E C! S% f/ \( H, J" d6 G grid-y-inc ;; the amount of patches in between two roads in the y direction& O; f1 B1 d, n9 E% r/ l- J
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ d P0 z" A: w% f! b ;; it is to accelerate or decelerate# T: k& Q6 A) e7 w1 p
phase ;; keeps track of the phase8 w$ s) y( m/ A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 T& j& j" l8 T9 a/ Z1 h9 w current-light ;; the currently selected light
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* |( A/ q8 J( [) t& B, N6 N! \8 a* _ ;; patch agentsets! Q1 U7 j. D0 V* r2 b$ I
intersections ;; agentset containing the patches that are intersections
2 l% N' h/ F9 Q) \0 |2 g roads ;; agentset containing the patches that are roads
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/ w& }# @- B* v" Q8 ]# t/ |- oturtles-own
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& d8 s1 x0 z+ d0 o speed ;; the speed of the turtle
4 @1 o' C/ z. X! ~; n7 l& {! s up-car? ;; true if the turtle moves downwards and false if it moves to the right7 M; O( B2 d0 K1 Z' ]! O/ c* L
wait-time ;; the amount of time since the last time a turtle has moved
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0 I8 `6 Y$ Q# C* g' e
patches-own
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V$ F4 c7 f) e intersection? ;; true if the patch is at the intersection of two roads
- e3 j8 X" a: l- I& R green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. w) C" T. u( s7 F ;; false for a non-intersection patches.
* ^4 O* H! y" {$ a& B+ A my-row ;; the row of the intersection counting from the upper left corner of the* E# q2 s' J6 o( S, k2 K4 y! f: t
;; world. -1 for non-intersection patches.! ^$ M# ^ K, M- \) F, m# \8 @( F
my-column ;; the column of the intersection counting from the upper left corner of the8 W8 b' m# L# j. c+ n2 K
;; world. -1 for non-intersection patches.
& T# C6 q$ {3 @& z8 p- D, n i6 S my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ U5 d l8 c3 `! r: v$ ^4 U auto? ;; whether or not this intersection will switch automatically.
- V; e' z' t! P3 N ;; false for non-intersection patches.
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% N$ s, ?5 \" l: B' Y+ ~;;;;;;;;;;;;;;;;;;;;;;; L# p' H8 c8 @$ S' S4 N0 p" S
;; Setup Procedures ;;
# m& f1 }! P9 M3 S3 A) N* i;;;;;;;;;;;;;;;;;;;;;;) d' @$ j$ \6 v) M" [1 x5 P
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;; Initialize the display by giving the global and patch variables initial values.
* i3 V* M! _5 P1 E7 `' ^3 `;; Create num-cars of turtles if there are enough road patches for one turtle to5 k5 x' h9 O2 \) P8 i- h" E+ o
;; be created per road patch. Set up the plots.
7 n! g5 A. I; V% q) kto setup
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setup-globals( W' H; U1 d5 @5 r, K o% h' i! a$ K
; I2 F* x' p* K5 T0 a ;; First we ask the patches to draw themselves and set up a few variables
7 a* v) A2 y$ b+ J setup-patches/ a6 x9 H: |9 B+ I& b
make-current one-of intersections
6 ^. d) P5 k" u, W( F label-current4 R' k. c% r9 j% t2 _ M
5 r# l4 |/ Z5 X7 g( [- ~4 A& y set-default-shape turtles "car"# P2 P2 ~' j& {4 L4 v, f! X
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if (num-cars > count roads)+ F. A# Z# l3 a6 Q+ ~4 m' J5 i
[, X, |& n5 L# L6 I8 k2 z
user-message (word "There are too many cars for the amount of "3 y3 E1 \8 x7 I! m3 d3 _
"road. Either increase the amount of roads "
: h, t( k1 v( _" A/ T" W+ V "by increasing the GRID-SIZE-X or "
2 [4 h- p% |; @3 B "GRID-SIZE-Y sliders, or decrease the "
8 |6 [( M0 Y3 i ]/ k, M( O: {3 o' M5 N "number of cars by lowering the NUMBER slider.\n"3 a1 w+ v& z- p2 @+ f! x& {
"The setup has stopped.")
( ^. r+ H) u {% c& p5 k2 Y stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: f. X' \' E: j; ], {- K" p9 [ crt num-cars: |3 _$ b, p4 |0 I6 M. y% ]
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setup-cars
Q7 f ^! j5 O# b set-car-color. I+ |. m% ]( b: S* k. f' t" q4 g' W
record-data
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0 b- I* b5 Z6 u ;; give the turtles an initial speed4 h) U* Q1 B' ~0 i, P
ask turtles [ set-car-speed ]: d; R8 z4 z1 s; ^1 x" y
7 B8 I2 R) O# w. j+ P, I2 O reset-ticks
6 [. R. G8 m* W8 ~4 V6 F, Z. Fend
+ v6 K. o. ~' ?' l4 N l; g! n
( f1 @3 E( {) a* {9 c" C;; Initialize the global variables to appropriate values
5 Y3 ]8 N' S. s, |6 U) kto setup-globals
% ~7 M7 w6 x1 A set current-light nobody ;; just for now, since there are no lights yet5 t: d1 a) i& i4 S3 Z7 [
set phase 0) T: C3 E9 K1 b |* \& _
set num-cars-stopped 0
) _; l" N, R4 p/ `' L set grid-x-inc world-width / grid-size-x) T+ A9 U) `* c" f5 y4 J) x
set grid-y-inc world-height / grid-size-y3 V) z! l& b. {1 a a+ U% R0 C' n
& k- @! c: P) P0 C4 T4 h* _6 V ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( L& E, s T3 U4 [4 \5 }; p
set acceleration 0.099
2 ]4 s7 Z, O( u- o0 R) L! pend
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& ~4 j. N4 D! h5 f; ~;; Make the patches have appropriate colors, set up the roads and intersections agentsets,5 m9 V3 d/ n9 m+ Z! R! ~
;; and initialize the traffic lights to one setting' q2 P c- Q% z
to setup-patches+ r6 }5 X8 b" e; d
;; initialize the patch-owned variables and color the patches to a base-color
7 I! {& \. W v- F% l5 y1 ^' l ask patches Y& U4 C7 X/ z% e1 p' _
[
2 H8 j7 A( M* n0 z7 K* n- ?. s: w. y set intersection? false
9 I$ F8 G$ c/ M# Q+ `: F L6 T set auto? false
! g- V4 X# N' W4 \) W set green-light-up? true
8 M5 n/ x0 j+ T' x6 m" v set my-row -17 e1 c5 s: n# n) ^6 o! q! @$ P
set my-column -10 z% t7 g O; b' I
set my-phase -1
: O+ H8 S4 v" P3 z set pcolor brown + 3
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1 ]' v. J% ?7 q1 t1 u) N4 f
;; initialize the global variables that hold patch agentsets
4 i* H) f2 |& P4 K set roads patches with
* H% e5 w C* A% k/ Z9 \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 c$ d% ^ y/ y9 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. ]% L$ D: i9 F6 B
set intersections roads with0 s+ ?3 o$ m! T# e) ~! D) `: u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and K8 y- G1 |9 _* \( H2 Q! \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. S, ~2 x& r8 J- b# D
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ask roads [ set pcolor white ]! b/ C* v" W2 f$ ^
setup-intersections# K8 E. B4 u, v
end
% \. z2 I4 D/ a其中定义道路的句子,如下所示,是什么意思啊?
1 v5 v5 ]' T9 |5 f7 D& i1 n set roads patches with
8 L$ c9 D. W/ B; C! |- q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* K' C/ n. @5 s- ^( c& _2 L7 T/ h( ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. D0 t) D5 r h9 ]' 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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