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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。2 ?* | t, i) h7 a' r! m
netlogo自带的social science--traffic grid这一例子当中,
' @/ i9 N! }; ]5 [3 Aglobals( [ ? Q$ e/ Y! i7 p- o6 F
[
, s! ]. @, X3 l8 d+ o grid-x-inc ;; the amount of patches in between two roads in the x direction1 F9 V: t( \' Y
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 n6 l6 \) c6 q' R; j* }( r) Q acceleration ;; the constant that controls how much a car speeds up or slows down by if
- Z# N1 T, m: s, b: x ;; it is to accelerate or decelerate
8 K( Q. Y1 w' R. [* V phase ;; keeps track of the phase! j. G0 L* [; u+ z2 l I J* I
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 J& @% G6 W2 _/ d, v. n/ E current-light ;; the currently selected light4 f) {1 f; `& }9 R+ T, s* v
d+ I/ F- F- X% h+ R- ~) Z ;; patch agentsets9 f6 ^( Y) f4 |0 ~( \0 A. q
intersections ;; agentset containing the patches that are intersections
7 N9 \ N9 N' B roads ;; agentset containing the patches that are roads% ^+ }" J! b4 ], H/ W% r# ^! x E/ Z
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& {: H, E7 T5 T& T2 j) I- pturtles-own( ^- q9 q8 O0 f1 w% M6 w2 q& W
[
+ C" v* N* X7 D0 B speed ;; the speed of the turtle5 @# V* {4 ?* ]" j. ?( A
up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ p6 V$ C F4 X; n' [4 S# } wait-time ;; the amount of time since the last time a turtle has moved6 T, I5 O l3 E3 {# n
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( A' Y5 d+ P" Xpatches-own5 B( v) c' V6 X+ U2 Z2 k8 e) S2 r
[
! P" Q( m* _/ G: ] intersection? ;; true if the patch is at the intersection of two roads9 u5 f, ?! @6 S( |, o8 E
green-light-up? ;; true if the green light is above the intersection. otherwise, false.# G4 [6 a( ^( s2 R; V3 d4 J/ Z5 G6 G
;; false for a non-intersection patches.
1 w9 i, s3 R" u8 s- L my-row ;; the row of the intersection counting from the upper left corner of the
2 Y! U) }7 ~# G' ^% q, H ;; world. -1 for non-intersection patches.
; }5 O# S1 j) f. { my-column ;; the column of the intersection counting from the upper left corner of the' [; P# M3 A, B- H2 g
;; world. -1 for non-intersection patches., H1 t1 W/ V! [" w) w
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 e) {/ H) m: O6 W1 @ auto? ;; whether or not this intersection will switch automatically., f: j+ F# Z+ O
;; false for non-intersection patches.. \9 d. ~& o- l: u# }8 d t
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7 V. }5 N! x4 k9 J: |* A;;;;;;;;;;;;;;;;;;;;;;
3 b$ U7 H9 O& s* s. p4 `;; Setup Procedures ;;
( o) v) l" S' b" d7 t7 m& };;;;;;;;;;;;;;;;;;;;;;( `8 D8 K: U9 A- z! X
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;; Initialize the display by giving the global and patch variables initial values.
/ g* X& O- n3 \6 h" ^& J, N2 E/ D;; Create num-cars of turtles if there are enough road patches for one turtle to5 N- }( C: U; ?+ B& E
;; be created per road patch. Set up the plots.* P+ P* S* b4 p$ y8 W& N
to setup; m/ h+ @0 _( W( k
ca
* F; F( m: d- l' ?0 |4 e7 `* Z setup-globals) {* z, t4 E& o3 N) v
1 R5 }1 u8 e; R5 z: D b
;; First we ask the patches to draw themselves and set up a few variables' a+ o }. `, n0 c
setup-patches. g- k& B) z, j
make-current one-of intersections
; U, A* Y' H) b1 K8 V5 Q label-current- g' ?3 ?: ?9 \, a
& x7 z/ M) X* u9 O/ O set-default-shape turtles "car"( Z% r5 `+ H# j* J/ f
) P& }; x7 p' z4 y8 a6 x if (num-cars > count roads)
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2 B0 L5 T% M8 A9 N/ \ user-message (word "There are too many cars for the amount of "1 M/ S7 g: O$ d. Q0 L- j5 H
"road. Either increase the amount of roads ". B) O2 Y+ @. H3 r3 l- k! N
"by increasing the GRID-SIZE-X or "
. h- ?0 z( w4 E; h4 C' B6 ~# u4 k6 @ "GRID-SIZE-Y sliders, or decrease the "4 f$ D4 ?4 ]' l; ]# I3 U
"number of cars by lowering the NUMBER slider.\n"+ l$ A& f+ W9 u [! r) r
"The setup has stopped."); g9 y+ E- B8 q7 p7 t
stop. ~" `3 s( q9 f) A
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6 |: R, Q8 S8 x8 R$ T1 R" A ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 q( `" S% R! n crt num-cars
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7 T. ` ]3 ]6 h h0 b$ M. L setup-cars2 `7 l3 N2 N( m! t5 g
set-car-color
& G) x0 x1 u! j record-data# N/ E- X- H* i2 R) f
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/ r" s# O# {7 E3 X' @# v# @ t ;; give the turtles an initial speed
, \/ E9 a: u3 [" _ ask turtles [ set-car-speed ]
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9 S+ P# f7 M7 t reset-ticks0 t7 {; J! n& A6 [; }; r; U
end e3 I$ y- p) o% P: b/ b0 E
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;; Initialize the global variables to appropriate values
) |* H+ s- B7 J7 ]# e$ Hto setup-globals# o6 B3 F* c6 O" c3 M( _
set current-light nobody ;; just for now, since there are no lights yet
6 P8 a( u6 X$ K$ I# t set phase 0- T: e( u! y" H1 t4 M; \* e8 i% B
set num-cars-stopped 0
5 o1 _- ~, e& V# P set grid-x-inc world-width / grid-size-x
" r# l* ?: X2 c. ?+ O$ i. ^ set grid-y-inc world-height / grid-size-y6 ?" [- J3 G6 ]
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 U7 B% \9 s" U7 w% X5 m# } Y0 |- ] set acceleration 0.099# B L7 f7 |! y7 i, b2 W% O6 F: K
end% i, m2 | ?/ }% Q! R8 A& n
! m2 s5 J/ M$ o;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 Z4 P6 e( u/ ~;; and initialize the traffic lights to one setting% T0 P+ \. H( J* l, d
to setup-patches
. C3 y/ R2 r* U; [' S( K/ A ;; initialize the patch-owned variables and color the patches to a base-color
2 E1 f% {( W7 I" t6 ^ ask patches5 X) O. b% N5 G. `
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set intersection? false
' R" ~3 Z a S6 e. Y set auto? false
; A. L0 Y* u6 W+ f- x set green-light-up? true! D9 M E) U3 u, s/ M
set my-row -1
9 _7 O5 t2 w# w4 N$ p+ H set my-column -1
" z, W" C" l1 U+ r* I. h9 ` set my-phase -1
1 G6 n% V3 D2 Q7 l3 Z set pcolor brown + 37 B' G# L3 K" x s; B+ B; y
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4 d6 p/ }7 A( A' Z) U ;; initialize the global variables that hold patch agentsets
6 u& _+ S l7 w1 i" c set roads patches with
6 g. i/ Y4 ?5 Y- _+ w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 S- E: A/ R$ M. g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" _, w6 o5 M" q: ^. T set intersections roads with
c) j( ~( l8 r0 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; @/ [7 o+ |7 v' W; B0 f/ o' w (floor((pycor + max-pycor) mod grid-y-inc) = 0)], @2 F$ d# m8 U+ g2 A' z
( V# j& x1 `7 L3 D! q A0 q, s: d. F- S ask roads [ set pcolor white ]
$ _3 r" p R9 J setup-intersections
$ u- p7 @( {2 X# M" Vend
% w/ J1 Z/ |) O, e, y2 j" x其中定义道路的句子,如下所示,是什么意思啊?5 @+ o' ?5 p' a3 @3 U
set roads patches with1 S: {$ E" P# A5 b8 g" G1 f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( t5 n/ C7 K# v, L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' X0 c6 d0 m6 S- R8 X5 a
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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