thanks for reply but still i am not answered.

can u tell me the equation of a helix with pitch b, radius a and its axis along the vector (p,q,r)?

- joshi[/color][/b]

[b][color=red]my answer is

to get a helix

set vx and By to perform circular motion

add vy for the uniform motion

i did not work out the equation for infinite cases like what you are asking for.

i just tell the simulation what to do and step increase in dt.

maybe i don't know the answer to your question.[/color][/b]