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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。' B8 [6 A$ Q6 f+ h( x& H$ b1 |
netlogo自带的social science--traffic grid这一例子当中,
5 W; [9 U5 v5 bglobals& T! H$ Y8 T0 \, a0 v
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1 b6 R, s. K/ t0 t( `7 ? grid-x-inc ;; the amount of patches in between two roads in the x direction! U$ C- k+ p; m6 b8 P1 c
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 I% [" J2 h- _8 N3 F acceleration ;; the constant that controls how much a car speeds up or slows down by if) p+ e l5 Y) S& f
;; it is to accelerate or decelerate
' m5 @% ?5 `% G ]% s8 s phase ;; keeps track of the phase
' b' X5 L1 c) V- [# d* P; Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( s4 n, l, E, t9 i. v4 y) H% p current-light ;; the currently selected light7 d f9 C* P* h0 d
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;; patch agentsets& y7 C! W/ g8 z: [
intersections ;; agentset containing the patches that are intersections& E/ U0 `* T. X( w2 ]# D9 n6 G
roads ;; agentset containing the patches that are roads4 Z( G- k1 Q8 [) H0 B
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turtles-own7 v9 l% W. \- m% H0 f$ o5 ~3 @- _
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9 W& v6 P5 O$ z3 s speed ;; the speed of the turtle, y8 k$ l, N5 \: O. F
up-car? ;; true if the turtle moves downwards and false if it moves to the right& |+ z" p: c+ p ?
wait-time ;; the amount of time since the last time a turtle has moved6 f: H3 s# U$ |0 P) r* S
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# V; `8 D8 e/ W. |patches-own! R8 n8 f; q2 ?: Y! X; ^/ }
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intersection? ;; true if the patch is at the intersection of two roads
; |* R' t% W8 y, {/ `) d/ F green-light-up? ;; true if the green light is above the intersection. otherwise, false.# ]9 a( @3 F g F( ?( p1 u
;; false for a non-intersection patches." T3 W1 S9 E/ ~& h( Y% Q' Y& P' q
my-row ;; the row of the intersection counting from the upper left corner of the
7 Q/ @; G/ s) V/ m ;; world. -1 for non-intersection patches.
2 q- r# q0 m, m5 f2 u3 ? my-column ;; the column of the intersection counting from the upper left corner of the* n5 A) k0 u, g! R) r( M
;; world. -1 for non-intersection patches.7 [" v) L. F. c
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' ~+ V; A9 w: f auto? ;; whether or not this intersection will switch automatically.
4 i1 r' P" e6 ^7 P& p* I8 v) J ;; false for non-intersection patches.2 V- ], `6 S' e: y
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8 @7 E! d" D" z" y" W* G;;;;;;;;;;;;;;;;;;;;;;
; c3 c2 X3 E) g* c9 p;; Setup Procedures ;;
. w3 ?# C" h7 U0 p! w;;;;;;;;;;;;;;;;;;;;;;3 K. f5 f- K v, Z, }+ r
3 X# ?# ? i/ K& J v;; Initialize the display by giving the global and patch variables initial values.: |8 a8 ?3 ^0 `7 D/ x7 @
;; Create num-cars of turtles if there are enough road patches for one turtle to" W" Y; M+ X) }. u
;; be created per road patch. Set up the plots.( ?- ~/ G7 r$ t, R( v: v M0 Z
to setup# {, q) p: E7 M' |, {$ ]5 [
ca
$ w0 e/ N' C( _/ j2 y setup-globals
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- [( b* b2 u. r ;; First we ask the patches to draw themselves and set up a few variables t3 N e7 z K. P( B
setup-patches3 a* r, j2 Y# c' c1 a% F
make-current one-of intersections: J; ^. B# _! A' X- f# S" X
label-current6 M( `8 a" V- h0 T
O/ _5 [: N6 f# y& n. T/ O set-default-shape turtles "car"3 O$ a9 D7 i% d/ j, @
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if (num-cars > count roads)# M' } @+ F: Q( j3 F6 _
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) h' `% x2 X: I. Z% x r2 @/ Y/ W) r user-message (word "There are too many cars for the amount of "
6 t* D6 j5 s8 z. k "road. Either increase the amount of roads "7 @7 r- \- Q6 T; w3 x* E* [
"by increasing the GRID-SIZE-X or "6 ?/ C$ ~# [4 m
"GRID-SIZE-Y sliders, or decrease the ": B9 M% c* ?! R1 Y, c
"number of cars by lowering the NUMBER slider.\n"7 l% x8 C0 W# y7 w( |5 U+ |
"The setup has stopped.")$ J- @- D r4 v( r$ W; A
stop2 I( t: d% S& C6 x _
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% h; y; ^2 D" @( X4 o6 Y ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& p% c, @, S; D& S0 G
crt num-cars/ ?+ N7 s5 u& Q4 d+ o
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@1 r7 o5 {% a X* k setup-cars& M0 k7 m0 Z" c
set-car-color
S9 T6 s, _% ^8 g+ J. N: a record-data
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/ {) f$ s. O7 h5 R( z ;; give the turtles an initial speed
5 c7 ]( h8 q; {* j& |$ S" i# X! p2 x' f ask turtles [ set-car-speed ]
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reset-ticks
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# _7 L- y# {1 q! };; Initialize the global variables to appropriate values
5 [6 k8 Z4 k6 hto setup-globals" P; o# a# o, Z* N
set current-light nobody ;; just for now, since there are no lights yet, `4 r8 A- V7 ^4 @/ F
set phase 0
; B% z3 G; }% m3 L. I9 I set num-cars-stopped 0
0 i. } v' h# y; P: s: Z% o% J; j set grid-x-inc world-width / grid-size-x
# v" a7 h, Y6 _% f set grid-y-inc world-height / grid-size-y7 R, n Y, m1 f8 D
5 z* e+ L5 y1 G+ g7 j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) B8 q }" o! z- X$ V( S set acceleration 0.099: H3 h! ~4 Z0 q! C
end. B- Y9 E8 r- j
( j v6 ~/ _9 o& c7 M* e% b. F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 V8 g2 X; W( |
;; and initialize the traffic lights to one setting
& }; `2 a7 H. K' X; H" e7 V0 \3 Zto setup-patches
# `% K/ K, V8 I- ~# Y2 D; N ;; initialize the patch-owned variables and color the patches to a base-color, \5 }. A, p: q4 o
ask patches
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) r$ L& Y! ]5 a1 K6 O set intersection? false
3 w/ ]" v. j0 L* w9 [ set auto? false
: F; ^( R- C7 |% \& q# J' i set green-light-up? true3 E4 F9 @) s5 o& c7 ~0 b c7 S
set my-row -1
9 c7 f% J' l" w ~7 B- F9 ]1 \ set my-column -12 v: K9 F6 l" U: A* _. z4 O& U
set my-phase -10 P) r( E: m7 n, [+ J0 r! @
set pcolor brown + 36 S5 ?2 v0 q. H- Z9 l8 b) p$ D$ L
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6 [6 J9 k5 z, _5 r/ c3 O ;; initialize the global variables that hold patch agentsets- t2 ]5 Y! E# _" g C+ V4 N* d
set roads patches with, j G9 x1 `& S* V& d" z6 e" G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" ?- I$ c( r3 A6 q! z' ?1 M6 o% m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 @% Q$ T& q3 Y# [ C
set intersections roads with+ P# j# `& b& N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% D, h: V$ U: ]4 ~. q* d5 w9 P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 @: a" }% q/ p$ v% G
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ask roads [ set pcolor white ]; }7 e! R" }* J- s
setup-intersections
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! j1 a, i# a9 A" C其中定义道路的句子,如下所示,是什么意思啊?# r" e y9 w: ?) G# B, P- Z
set roads patches with& ]! M9 Z% ^) M4 q; h) E% J: s. o& N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 a- \1 h6 I0 @, M/ ?& H% F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 u! [5 E1 O% t* W- i8 @
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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