Is there a sin() function in PostgreSQL? I need to create a view in
PostgreSQL that uses sin(x), and the only real mathematical functions I
see supported are dexp() and dpow(). I tried using dexp(I) to get the
exponential of an imaginary number (which would make writing sin() easy),
but this didn't work, since dexp() expects a floating point argument. Is
there an easy way to get sin()?