hello! how can i interpret a formula like this:(x, y) = (rcos(q + r), rsin(q + r)) in vvvv?

hi taso!
what do you mean by rsin, rcos?
is it the arcsin, arccos or just sin, cos?

in the later case you will just need a circularspread with center at 0,0 and width,height=2. you would then input q+r as the phase.

if rsin and rcos are meant to be arcsin, arccos then you would use two expression nodes.
for x: arccos(a)
for y: arcsin(a)
and input q+r into pin a of the expression nodes

sorry r = radical of (x2 + y2), this must be form a swirl?
is there a sin or cos in vvvv?

ok ! i found it. it was the phase of circular spread.
also i read your page wave simulation, now evrething is clear!
thanks gregsn!

also found the node expr(value) !
i like vvvv!

also have a look at the node category ‘Complex’ and open some help patches. most 2d problems can be solved with complex numbers, wich are basically 2d vectors.