1. Re: bullet code (was ICONS - dead horse)

Your code looks a bit misled and rats nest-like. Unfortunately you are trying
to do something iteratively (read: the hard way) when it can easily be done
algebraicly.

If you want the position of the bullet with respect to time then try

----begin code----

constant vx=1,vy=1 --initial velocity, x and y components
constant dt=.01    --time increment
constant g=9.80665 --gravitational acceleration
constant xmax=500, ymax=950

atom x,y,t
x=0 y=0 t=0

while x<xmax and y<ymax do   --this 'and' might need to be 'or'
    x=vx*t
    y=vy*t - .5*g*t*t        --t*t is simpler than power(t,2)
    plot(x,y)                --replace with your plotting function
    t += dt                  --increment time
end while

----end code------

alternatively, if you only want the path of the bullet and not a real time
display of it flying then you can calculate y with respect to x

----begin code----

constant vx=1,vy=1 --initial velocity, x and y components
constant k=vx*vy   --I am a speed freak
constant dx=1      --x increment
constant g=9.80665 --gravitational acceleration
constant xmax=500, ymax=950

atom y

for x=1 to xmax by dx do
    y=k/x - .5*g*power(k/x,2)   --much as I hate power() I use it
    if y>ymax then exit end if  --bullet has left universe
    plot(x,y)                   --replace with your plot function
end for

----end code------

Have fun !

--

Daniel Johnson               Engineer, smartypants and clown
Jesus College, Cambridge     all at a very reasonable price
dpj22 at cam.ac.uk
zeus.jesus.cam.ac.uk/~dpj22  talk dpj22 at jewish.jesus.cam.ac.uk

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