I am not an expert in mathematics, I am only a young programmer. I am trying to construct a spherical tag cloud and I've found this formula:
for i,t in enumerate(tags) phi = acos((2* (i+1) -1) / tag_num -1) theta = sqrt(tag_num * pi) * phi x = radius * cos(theta) * sin(phi) y = radius * sin(theta) * sin(phi) z = radius * cos(phi) t.setPosition(x,y,z)
and it works fine. but I thought, for a spherical disposition, have to do 2 nested for: one for latitude and one for longitude. What kind of formula do I use in these codes? Can you explain me what this acos
and sqrt
do?