1; fname : ballexample.dat
2;
3; Illustrate basic usage of the ball.pos FISH intrinsic function
4; =============================================================================
5model new
6
7fish define get_ball_position_vector(bid)
8 ; retrieve the vector position of the ball with ID bid
9 local b = ball.find(bid) ; get address of ball with ID bid
10 local v = ball.pos(b) ; read access to the position of ball with address b
11 get_ball_position_vector = v
12end
13
14fish define set_ball_position_component(bid,idir,val)
15 ; retrieve the idir component vector position of the ball with ID bid
16 local b = ball.find(bid) ; get address of ball with ID bid
17 ball.pos(b,idir) = val ; write access to the idir-component position
18end
19
20; set the model domain and create a ball
21model domain extent -1 1
22ball create id 1 position-x 0.0 position-y 0.0 radius 0.1
23
24; create the global FISH variable vp1, execute the get_ball_position_vector
25; function and store the program return value in vp1
26[global vp1 = get_ball_position_vector(1)]
27fish list [vp1] ; output the value of vp1 in the console pane
28
29; execute the set_ball_position_component function to assign a new x-component
30[set_ball_position_component(1,1,0.1)]
31
32; execute the set_ball_position_component function to assign a new y-component
33[set_ball_position_component(1,2,0.2)]
34
35; use inline FISH to create the global FISH variable vp2, execute the
36; get_ball_position_vector function and store the program return value in vp2
37[vp2 = get_ball_position_vector(1)]
38fish list [vp2] ; output the value of vp2 in the console pane
39
40program return
