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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。8 L4 U0 D0 A: G3 Q9 T' o
netlogo自带的social science--traffic grid这一例子当中,
# v; W" n4 D; d; e! pglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
1 a! ^+ d6 }4 \2 Z- V4 W grid-y-inc ;; the amount of patches in between two roads in the y direction: p% D' ~! K- V1 {) i& P% V1 A
acceleration ;; the constant that controls how much a car speeds up or slows down by if& y o- B" A9 A: C Y% Y' ^3 x
;; it is to accelerate or decelerate9 K$ x; R: ]- ]( X% W, j2 `- u
phase ;; keeps track of the phase- V) p2 W8 Y- O4 p: d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, L: o$ y H9 C6 D; M* E* g current-light ;; the currently selected light
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;; patch agentsets
* U( Y- {& [) X1 {7 A9 D intersections ;; agentset containing the patches that are intersections3 w8 `* O/ C d' Q; @
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
% Q7 l( z t/ K# C0 Z& s! z up-car? ;; true if the turtle moves downwards and false if it moves to the right9 I D1 [6 F# e( _. s2 m4 a8 ]7 e
wait-time ;; the amount of time since the last time a turtle has moved
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4 n8 ~0 Z: q& K& Zpatches-own+ {% v/ _$ {, O% Z8 i, V
[
8 U8 O0 a" G+ d7 Z t intersection? ;; true if the patch is at the intersection of two roads: ^: Z" e6 \4 q. T7 Z Z
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! F3 i' n, ?8 Y6 @ b! f ;; false for a non-intersection patches.( F; h- E& Z. u* t" p
my-row ;; the row of the intersection counting from the upper left corner of the
k) F) C: o; P5 m3 n2 l ;; world. -1 for non-intersection patches.
6 Q U5 n @* c- [, u9 Z my-column ;; the column of the intersection counting from the upper left corner of the! [1 \% N4 X6 ^, l
;; world. -1 for non-intersection patches.. Y. G4 |, L: v: u
my-phase ;; the phase for the intersection. -1 for non-intersection patches.( H0 L( u8 l2 B. M
auto? ;; whether or not this intersection will switch automatically.8 x8 T* U4 r/ B2 [6 [: w/ G
;; false for non-intersection patches.( o8 z+ r7 a6 [
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2 C% ]7 S2 B: g5 E. C; x;;;;;;;;;;;;;;;;;;;;;;- L# Q. {8 `; n3 `/ M
;; Setup Procedures ;;
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& W) D c) F/ f;; Initialize the display by giving the global and patch variables initial values.
7 \2 r, w8 |$ X8 S! U! f& C: _;; Create num-cars of turtles if there are enough road patches for one turtle to
8 d( {& W3 F3 w- g+ J% {0 K;; be created per road patch. Set up the plots.7 F( j3 ?& C0 c Y- b
to setup; i4 } \0 q' m6 [4 M4 {! m
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setup-globals. I. V6 x: z4 M0 e
7 h3 K' |2 d0 C4 o& f$ _ ;; First we ask the patches to draw themselves and set up a few variables
5 r }* A7 a& B' E) x" ~ setup-patches8 I) w5 V# _1 F' D9 u# ]
make-current one-of intersections: E- E0 |3 `' \2 g
label-current
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$ R. o3 _" d' j set-default-shape turtles "car"
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) j# N: n2 B# D9 B3 |3 i8 k0 z) Z1 p if (num-cars > count roads)* _! v: B q9 a" F, R* v; {( f" `
[
3 G3 ~7 w! {8 S# o user-message (word "There are too many cars for the amount of "* L7 F8 W2 h0 ~* i2 E& ?! Y! ^
"road. Either increase the amount of roads "
$ z7 G. }; K: x, @ "by increasing the GRID-SIZE-X or "- q4 U' h7 K- z( {4 C
"GRID-SIZE-Y sliders, or decrease the "
0 Q7 o; G8 O; ^* A "number of cars by lowering the NUMBER slider.\n"9 i) x4 `7 U( T) J) L. A! u
"The setup has stopped.")* Z3 u7 a0 Y# C: v% H
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color0 }$ V9 m0 L& \' K: f
crt num-cars
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2 s: {1 ?/ ~$ N, M setup-cars1 V) T; p% W$ U2 B0 h4 j8 A
set-car-color | a" Y& O k3 Y* U7 V
record-data
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;; give the turtles an initial speed
& D$ K; k4 T# e. o0 h$ R ask turtles [ set-car-speed ]- N- j* r" |9 B- z
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reset-ticks
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0 I: d) Y( [9 x! x; S1 I. s N;; Initialize the global variables to appropriate values1 L* G; U3 l9 P& e
to setup-globals: ~- d* K7 |. v+ O) d$ s7 F% r
set current-light nobody ;; just for now, since there are no lights yet% r6 x, l% m* ^
set phase 0
9 a, {0 z' u# q! T! a2 D2 T set num-cars-stopped 0
. A1 @' ?; Y; }, @: ]5 C! |, u set grid-x-inc world-width / grid-size-x
0 b# \* v) u- I: i1 U. ?% {6 f set grid-y-inc world-height / grid-size-y! b# r* w( t+ Y. q
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 b" f1 c0 ~6 g4 F! V set acceleration 0.099- D& S8 x! _4 s e0 ]
end! q& Q9 a$ M3 G
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 l7 ~% ` T2 m, ~- G
;; and initialize the traffic lights to one setting9 Z! [0 N, }# q* M( D
to setup-patches
- `, e D" g7 w9 ~ p: x* e ;; initialize the patch-owned variables and color the patches to a base-color$ _, {- v1 P& _& s; I/ r: q* l
ask patches4 k; M2 S' [; [
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set intersection? false! j7 r5 M/ ]& ]- [: v' @/ z
set auto? false% e ~0 p o% `7 ?( v+ I4 k
set green-light-up? true# q6 o; c, w& e4 U) p+ P. m
set my-row -1
- g0 c7 O) U4 n0 I/ ` set my-column -15 a( w+ [2 |6 @0 k! D2 O
set my-phase -11 Y( [: k K3 s' A9 X
set pcolor brown + 3
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; W/ @' t x0 i0 G ;; initialize the global variables that hold patch agentsets
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8 v+ E+ `) i7 u/ B5 F \7 r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; B+ x5 e ]' L% x% P& w" S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 J& n+ y8 n: S% } V8 l& ^
set intersections roads with
9 q) J4 v# I( D7 i. o. ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. W( {2 _& P) B. Y/ ?1 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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% ~0 M) D# [% T6 { ask roads [ set pcolor white ]" S! r/ A/ c1 x. G
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?
. K. {7 d: U4 K( e, H set roads patches with
8 E% j6 ^# m3 H2 o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 k- X: p. t7 @3 e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- Q& i" R! f+ b, j0 X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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