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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。- A5 u/ W+ ?; s, x% E
netlogo自带的social science--traffic grid这一例子当中,6 E8 X# y& y# ^# j8 C2 ~: ~
globals
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2 K% e8 B7 @, g, ~3 y4 z! a grid-x-inc ;; the amount of patches in between two roads in the x direction
6 c+ d! R% U2 z6 r/ Q" o grid-y-inc ;; the amount of patches in between two roads in the y direction
% x2 J" v: O! @% C9 S" g6 ]0 }" H acceleration ;; the constant that controls how much a car speeds up or slows down by if. v8 F1 Z2 o p. Q j1 O2 o. G
;; it is to accelerate or decelerate
6 [6 r, X8 ~8 n, y5 t# T phase ;; keeps track of the phase
3 T" j, w# P7 F& o; V" B1 L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 {) Y. J9 E5 o E+ k& z
current-light ;; the currently selected light, b0 F" Q8 j0 p3 c6 e
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;; patch agentsets n E6 ^* N2 U+ H
intersections ;; agentset containing the patches that are intersections) E* K/ z$ g1 k
roads ;; agentset containing the patches that are roads1 ?1 u: {; s! T6 u4 [& m
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turtles-own9 Q; m! b3 R- O, Y
[
9 V8 L" p# x4 l1 h% e, d% y speed ;; the speed of the turtle
' ^$ L. ^/ g/ m% ]3 A up-car? ;; true if the turtle moves downwards and false if it moves to the right% x( s3 K: L" A d( @8 D
wait-time ;; the amount of time since the last time a turtle has moved/ T. o9 e# E8 c. a& A5 X7 W
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patches-own* U y' o3 w8 g) e1 `
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6 L6 \1 M6 A, s1 E8 ~6 i9 _ intersection? ;; true if the patch is at the intersection of two roads
, c$ K; N" X& O- G5 O$ L green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 o3 y$ g2 P" Q) Z' l6 `0 ?! N
;; false for a non-intersection patches.
9 O5 ~6 h+ U+ G8 e! \. q2 X" J my-row ;; the row of the intersection counting from the upper left corner of the
7 g9 ^# N( V. S" c \5 E* x* j ;; world. -1 for non-intersection patches.
+ b' P5 U4 `6 h3 @" S my-column ;; the column of the intersection counting from the upper left corner of the
) Q7 h. ~2 H. S7 ^ ;; world. -1 for non-intersection patches.
: s, }- i6 R+ S9 A5 W my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 V/ A8 Y) y- u3 x$ F9 c auto? ;; whether or not this intersection will switch automatically.
+ f. V: r$ f9 r; Z3 U" c+ ? ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;0 b9 ^+ @; V- _
;; Setup Procedures ;;
% r9 ^) v2 J w; o# h;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
# _0 q; y4 q. |, k7 e;; Create num-cars of turtles if there are enough road patches for one turtle to
8 t; [! I$ r2 x$ J! | d;; be created per road patch. Set up the plots.
4 z! U6 r, k, `8 eto setup$ I* X# U2 e7 z- O4 A( ~# L3 x9 ` ?
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setup-globals$ z1 a X* z, A; x7 s8 h
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;; First we ask the patches to draw themselves and set up a few variables2 M/ L f& s' X p
setup-patches) I1 _, h3 \) _( F& b
make-current one-of intersections
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& |1 V3 }, i2 v set-default-shape turtles "car"3 X, r7 Z* o# Z) g$ P& S
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if (num-cars > count roads)1 y( s/ ~$ `% o6 ?8 h" t v& d& I) q
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user-message (word "There are too many cars for the amount of "
) k) b3 C T+ c0 h Q "road. Either increase the amount of roads "
( |: `! f* B3 {' G7 y4 t, N! Y "by increasing the GRID-SIZE-X or "
0 v" R4 M8 I4 T+ U6 f& ~ "GRID-SIZE-Y sliders, or decrease the "! p3 W% {9 p3 [# e, }( e6 @
"number of cars by lowering the NUMBER slider.\n"; \1 Q& f2 ]+ v0 U& D1 t6 Q
"The setup has stopped.")* y T4 K- T& Q9 b) f& n
stop. `0 R7 G/ {( _9 u, ]3 D7 l; C) a
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7 f. k/ w' }' [2 X/ T7 j1 b/ v ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 t- |5 i1 o: m8 e2 r9 U ? crt num-cars& l( h' C: O5 p S/ a( A% X0 M" J
[
3 w) P) X8 x- C9 v2 q9 o/ L3 L3 A9 c setup-cars
# p% j1 {0 V" a1 ^ set-car-color0 a7 W. J$ m0 ]6 r
record-data. B6 U/ S- B+ A
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;; give the turtles an initial speed7 c2 i( d8 s6 H: e8 a5 S8 ~- ?
ask turtles [ set-car-speed ]6 z6 m& B2 Y! k x" a" f* {
" c9 _3 ~9 Q$ B+ i! X1 P reset-ticks
: ^: n& w. y$ Z/ B6 mend
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;; Initialize the global variables to appropriate values
- B! M- J& @! i Ato setup-globals
7 S4 _' j' i( W set current-light nobody ;; just for now, since there are no lights yet
1 `% D+ S) Y% W set phase 0! S, E& Y- v1 x: ^/ v- D# p) _2 X; F
set num-cars-stopped 04 R$ c, v7 J) I! S! o( d
set grid-x-inc world-width / grid-size-x' q$ R- t) W a% m3 c- D
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 boundary9 h2 Q8 I, ~# T4 c5 I
set acceleration 0.0992 W9 B* S) [7 _( N. s# c* P" V
end- u: v" ?& p7 }) j3 x8 p
M5 P" s4 d6 {8 z/ o/ c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 l7 a/ y# ^- I0 v, h;; and initialize the traffic lights to one setting
/ ^7 D/ [ N6 U: t4 y! Q5 n/ A; G Pto setup-patches
. q7 h$ B' X4 s: s ;; initialize the patch-owned variables and color the patches to a base-color
7 x8 ~7 q6 C: H9 ?) f/ o ask patches; @4 o! Y4 X. @2 r# A( l
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3 r# j8 l: e5 H7 c, @. ^; R# ?" t set intersection? false
3 R0 C- e# d: E/ n. Z* w; C set auto? false" g- ^% S( x; U# l4 f% y
set green-light-up? true
% N' ]' z- E* W9 f set my-row -1
1 |$ n- J# x; `0 f set my-column -1
4 e' J8 p; W% A) h; H set my-phase -1' _/ O0 B' j6 H) c8 |; y
set pcolor brown + 3, O% A0 m% H% d. ^0 g: `% [
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9 ~) `) n6 z6 ^7 Q ;; initialize the global variables that hold patch agentsets
# x' ?* Q. G& L! }/ z& {6 p& E set roads patches with
" l# Z" u" _2 V7 i& Y) R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; M* `1 m4 r8 V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! B* l9 ^% q& K' k; @& p2 N set intersections roads with4 m. R* d. o% A6 n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: k5 Z' g+ b( y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% U h4 g4 F. {1 T) f
) w T( C! |9 S7 ~7 x5 {( l 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?/ W! [( J v6 ]
set roads patches with! e2 m. }! @, w$ v" F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 G0 V n8 \$ p* J9 c/ W9 O% y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: t9 G- L+ f- _( f
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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