define double theta[2] k lwave nu jyperk
let nu  &1 /prompt "Frequency in GHz"
let theta &2 &3 /prompt "Beam sizes in arcsec"
let theta theta*pi|180|3600|2.|sqrt(log(2.0))
let lwave 2.99792458e8|nu*1e-9
say Wavelength 'lwave*1E3' " mm" /format A10 F10.2 A4
!! 'theta[1]' 'theta[2]'
let jyperk 2.0*1.38e3*pi*theta[1]*theta[2]|lwave^2
say "K per Jy" '1|jyperk'
say "mJy per K" '1e3*jyperk'
!
