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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。! m Z9 D: Y+ F6 s) w( [5 ~% T
netlogo自带的social science--traffic grid这一例子当中,$ n ^5 X& b6 d3 H- _8 E: x; i! S
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
; n! t+ u0 e7 x3 O) u6 k7 c4 X* | grid-y-inc ;; the amount of patches in between two roads in the y direction1 o) [, ?8 o5 @" G, {" v+ d
acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 ~: v3 r) @* {( { ;; it is to accelerate or decelerate
* i4 o r/ \" k8 J( w' \7 z phase ;; keeps track of the phase
0 y3 m# v2 Z0 w1 C2 L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. C" Y$ z! c3 i6 C
current-light ;; the currently selected light& V0 O0 S; l8 Y' \' f7 F
) |5 @$ ~" K6 t1 B X P/ a ;; patch agentsets
- `! n0 |9 {! C* k intersections ;; agentset containing the patches that are intersections" J. {, {2 l" |0 w1 x
roads ;; agentset containing the patches that are roads
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+ c8 ~- W& m* u$ I- }8 Rturtles-own
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+ u3 a/ r7 @4 Z6 v" e speed ;; the speed of the turtle4 X, d7 S3 [* {* A) u5 P; h2 s: R9 N0 P
up-car? ;; true if the turtle moves downwards and false if it moves to the right6 Y* s4 S2 i( G1 u' h6 ~- L
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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& E8 h/ _" r- u2 a intersection? ;; true if the patch is at the intersection of two roads' l* D& r3 ^( B- E/ F" I
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- S3 m) x/ X6 o ;; false for a non-intersection patches.' b# n- D2 l4 g6 H. d7 T
my-row ;; the row of the intersection counting from the upper left corner of the) Z; V# y( v, e' @; ] h2 x% b
;; world. -1 for non-intersection patches.
5 A/ w% U# e* H/ f* p# ]' W2 f my-column ;; the column of the intersection counting from the upper left corner of the
H; V- `! }; W: o6 e7 `, J3 i ;; world. -1 for non-intersection patches.2 @$ D9 G3 T/ e8 O7 M! z+ [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 _4 I. J1 U$ E' j9 ~1 _* W' ?
auto? ;; whether or not this intersection will switch automatically.
: `/ H$ a3 K3 A/ {# C1 w ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;3 `/ ]3 \* p& I9 u/ y
;; Setup Procedures ;;; l' n; p# F" K
;;;;;;;;;;;;;;;;;;;;;;
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/ b; U& b3 L" P& D) p;; Initialize the display by giving the global and patch variables initial values.
% y- v5 a( Q/ u* b3 X;; Create num-cars of turtles if there are enough road patches for one turtle to; a' N& j" V. z2 Y' R$ i4 b
;; be created per road patch. Set up the plots.
, I9 t* Z0 V* j3 s3 Fto setup
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setup-globals/ S7 L: w0 \) w: c/ S8 s
+ l- y. X8 G# o# k ;; First we ask the patches to draw themselves and set up a few variables8 b$ Z8 @8 x: q, l% ?3 h
setup-patches
8 J; x& |4 N4 S, K$ D: U, ?3 [8 d make-current one-of intersections
" ^5 a3 [% `, c. Y+ ` label-current5 L9 Q! l% M/ D: R% t( Y0 ~
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set-default-shape turtles "car"0 J5 m f0 y! W* R8 m
2 D4 T. y3 }: P7 c1 K6 d ~ if (num-cars > count roads)
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9 P% f- k; ~( n& g7 [ }( U user-message (word "There are too many cars for the amount of "
7 N' w F& t* E "road. Either increase the amount of roads "
- ?4 Q/ c. v% E9 z! @9 V- v- p "by increasing the GRID-SIZE-X or "
' F7 e) i; Z, d/ [2 `$ w "GRID-SIZE-Y sliders, or decrease the "
8 H) C1 y( Z- x; T+ x "number of cars by lowering the NUMBER slider.\n"
! [# U! l6 j. K& T6 i "The setup has stopped.")3 I, v, h% d5 V4 Y5 c& Z" Y' P
stop; e) H7 S, [- X& r/ D& Q |) d
]
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" e' h, \: {& D! D7 A ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars' s; G& l2 L9 s. x. }
set-car-color
! S% z$ t4 A; C9 p% i record-data g4 i- q' i' J, l6 Z i9 Q4 G
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;; give the turtles an initial speed# Q0 p+ C4 {; U7 x1 W
ask turtles [ set-car-speed ]
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reset-ticks. @2 `0 C+ _* n/ `
end
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! O9 v6 H T& e, p; f;; Initialize the global variables to appropriate values' X2 J( u! ?2 a3 u8 B
to setup-globals
% ^, M/ X9 I! Z& p: x8 m set current-light nobody ;; just for now, since there are no lights yet
# G. l) C3 }+ r! c b set phase 0, _7 x* A/ k9 J5 L' o( @
set num-cars-stopped 0% ^+ K: `3 O* V* n9 T V3 D. @
set grid-x-inc world-width / grid-size-x
6 b' Q( N3 R0 f9 M9 n set grid-y-inc world-height / grid-size-y& C3 b- l0 n& ~ _- j) X: n4 j
3 `) t- `4 h8 z$ i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, v# b0 _' w+ Q- @4 j5 O
set acceleration 0.099( {6 ?- J5 k( z$ s) \
end5 n" r* e+ K) g$ n
& O4 [8 r+ f+ V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ [& ~* t8 y& Y4 `+ H& n" C;; and initialize the traffic lights to one setting0 ]$ q: [7 q( _; X! o4 \
to setup-patches
: p: H% F" u1 p: d8 b. r0 j u( C ;; initialize the patch-owned variables and color the patches to a base-color1 l- z1 J( E+ O# ?3 t5 W/ y o9 X
ask patches
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9 d9 [6 F1 P8 J5 J, l5 ]3 U0 P) [# T set intersection? false
4 h9 y" B' J4 K) }- Z set auto? false% {+ `9 Q% } \5 V' W/ |3 J
set green-light-up? true5 T* S5 D: y9 i3 \0 r
set my-row -1; v0 X% R# V" ~4 ]) {
set my-column -1" q- B% t/ A9 E3 k8 v" i
set my-phase -1( i5 S) {, J- J5 b
set pcolor brown + 3
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2 c5 [) F7 d6 t! ~& H; E* } ;; initialize the global variables that hold patch agentsets
$ {: y# a M0 X set roads patches with4 X7 a: W5 a) N! r8 h9 j, Q4 D, j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ k3 a" }! n% m2 J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& Q2 F, x3 G/ f5 J7 K
set intersections roads with6 C' U& B7 Y. q+ j5 h9 H4 Q2 p b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; K2 f+ `) V a4 I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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9 A4 z- C' W% ^: |/ b, q* ~! k* q6 ] ask roads [ set pcolor white ]' N2 O5 J5 X3 n$ R# e% V2 ^
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?( ] C/ n6 H0 s+ n
set roads patches with. ]# k. a0 C" |- v2 z; C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 ]; E' n4 S, z- {1 ^ w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) }. _3 I8 I; H) B# }# J% E$ t
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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