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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。6 `% m+ d+ l( H
netlogo自带的social science--traffic grid这一例子当中,
8 R8 {7 K* V5 s% Uglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
; M" H7 o1 m4 K* [ grid-y-inc ;; the amount of patches in between two roads in the y direction" i6 U1 S1 j! f8 D" m9 u/ T6 L0 I( c" [$ W- p
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 `7 \7 Q- D% s# U# ^ ;; it is to accelerate or decelerate# b# {$ _# G- h, K; p. @& w
phase ;; keeps track of the phase
! H7 v. u' r3 Y0 t* |# q% e num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; Z: V# W# H% _+ F current-light ;; the currently selected light* d( ]/ ^) A, B# w5 f- E
w- u6 V9 A4 E- Z& v2 w ;; patch agentsets
' x2 Z4 O8 ]6 j* ~) T( i intersections ;; agentset containing the patches that are intersections* G3 k6 ]: |1 N, f: \: M
roads ;; agentset containing the patches that are roads4 y& R' H" `- j+ d* e; L7 I7 A
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& c/ A$ k4 h& N; Lturtles-own
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' E: E% i( ?# u speed ;; the speed of the turtle
' h5 U" a8 y0 s5 d3 e up-car? ;; true if the turtle moves downwards and false if it moves to the right: G; w% w4 [: Y. W) d3 b
wait-time ;; the amount of time since the last time a turtle has moved0 O' J. z" K& j) V
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2 n. m- @0 l4 V, R# M" o/ P6 @1 opatches-own. K1 }1 l: o" \$ V9 M3 _' E* R
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. g5 [. z/ E6 K* E intersection? ;; true if the patch is at the intersection of two roads2 J7 m3 `" k2 z0 s. t; b
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# ` k- K; r t' ? ;; false for a non-intersection patches.
' G' Z1 D7 B' q- o+ |. ~ my-row ;; the row of the intersection counting from the upper left corner of the c9 @! ?/ F1 q- z o) K
;; world. -1 for non-intersection patches.
8 O- l3 s1 X7 D my-column ;; the column of the intersection counting from the upper left corner of the
. R D2 U& ?6 B ;; world. -1 for non-intersection patches.
, n* m _7 O" k2 y" ?: w my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 m, c; | Y7 E/ w
auto? ;; whether or not this intersection will switch automatically.9 b$ T! {9 j4 B4 l7 N. ^. M) ]
;; false for non-intersection patches.- p+ Y7 r) M9 a2 v1 m7 T- e) [
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;;;;;;;;;;;;;;;;;;;;;;
5 ?4 d- I0 f. W1 l3 K: G;; Setup Procedures ;;/ s6 I3 q( ?' w
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;; Initialize the display by giving the global and patch variables initial values.7 J m9 o4 l1 ]% ^/ L. y4 b
;; Create num-cars of turtles if there are enough road patches for one turtle to) i: j. X! \' t& F
;; be created per road patch. Set up the plots.2 b* h) P5 ?5 Y5 k
to setup8 U5 f! Z# p5 Z" J
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setup-globals4 |+ G" h1 f. o
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;; First we ask the patches to draw themselves and set up a few variables
0 ]1 O u& y4 }& y9 {- }: q: a/ q, v setup-patches
4 ^/ y1 Q! E$ J5 a) `1 D4 V& X2 ?4 x make-current one-of intersections
8 L/ C3 V9 ]" Q8 X) j: z! f ~ label-current
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set-default-shape turtles "car"
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' p3 L" Y/ d+ \; ^$ e if (num-cars > count roads)
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! r4 A+ T! ]1 S4 Q user-message (word "There are too many cars for the amount of "
! j2 F- s% W+ I/ A" t% f3 ~- ` "road. Either increase the amount of roads "
0 R0 u+ ]1 E9 I "by increasing the GRID-SIZE-X or "3 r4 A" a. k: |; V% T9 O, n, Z
"GRID-SIZE-Y sliders, or decrease the "
8 z& E( u+ X" Y( N+ I "number of cars by lowering the NUMBER slider.\n"
* C) Q* G- F* P. c% e: p6 B& g "The setup has stopped.")# L& w, W% b$ e5 X' a
stop& {' W6 f" X$ Q: v# H
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* V7 K5 L/ c. L
crt num-cars
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- R& Z$ |8 }' ?+ Q a }, F$ |; c6 o setup-cars* ?/ G3 _. O; n- \5 @
set-car-color
( u5 k8 u4 U- M/ T' t6 T record-data
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6 @, B( S1 u/ v1 H: v% y- g ;; give the turtles an initial speed
) ] u$ F+ \( b& W3 O4 Q8 J ask turtles [ set-car-speed ]
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reset-ticks2 p# T( Z1 o: [) n
end
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;; Initialize the global variables to appropriate values
2 g. q& M6 F4 H* p2 O- z* k1 Yto setup-globals
7 j% e" s! q& s" f- q$ O0 a+ u; y set current-light nobody ;; just for now, since there are no lights yet% ^5 I( Q5 r+ h# E a4 ]; V
set phase 0
- {% N* i" y0 Q& G) @; i8 j set num-cars-stopped 0
: X/ V! t1 ] [5 h! ]4 c( ~1 r set grid-x-inc world-width / grid-size-x, ~3 ?9 \) F: e, ~+ ]
set grid-y-inc world-height / grid-size-y W* y! y! k0 x+ j4 J% G x# [
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary" T( o& e) w! b- ^) O
set acceleration 0.099" v8 s$ e5 C) z
end) `" b: A$ v! L- m" i! ]& e9 A5 N
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& B; j# n8 @0 d `. |
;; and initialize the traffic lights to one setting0 K+ {/ i% C" x9 \
to setup-patches6 t* j) Y! Q7 e6 E* [% v' L
;; initialize the patch-owned variables and color the patches to a base-color. }& d r! E2 }+ J) Q/ A! Z, a
ask patches N# _4 F+ ^( e) i: J
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set intersection? false
( J& l( _( [1 ^8 h9 t set auto? false
2 j* r% T! U2 H; u5 _ set green-light-up? true
0 L; u) R; v _1 E0 Q$ W G6 G set my-row -18 E; |( T4 v) p. C: H
set my-column -1, q& ?) Y5 J* p* E
set my-phase -18 k8 K* h3 R0 C( J/ d* z7 P& O
set pcolor brown + 3, \0 v6 G4 k2 F9 F* v5 T
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;; initialize the global variables that hold patch agentsets* M A4 _* s6 f3 [% F: O
set roads patches with
4 W( k [5 _) b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 m7 V W5 W9 i1 U% ~% q- m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% v/ p% J6 u, G: W, X5 _
set intersections roads with1 k: V1 j: F% v$ u8 m' ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& [- { f6 K# q" G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]4 Z2 }( T6 V" r9 Q: R7 _% C8 j
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?
1 o, L4 F7 ]8 }. i$ @ set roads patches with
& Z0 o6 Q7 B2 t. x* s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 h5 F1 `: B- D$ Y7 e* } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, h% w" z5 {' y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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