NAME: lcfun PURPOSE: Compute a lightcurve function (Fourier series plus phase coefficient). DESCRIPTION: This is to be used in cases where you already know the fundamental period. The input independent variable is assumed to be reduced to phase of a fundamental period already. The integer part of the number is not used by the function. CATEGORY: Mathematical CALLING SEQUENCE: lcfun,x,c,f,pder INPUTS: x - independent variable (longitude, between 0 and 360) c - fourier series coefficients 0 - beta -> linear phase coefficient 1 - a(0) -> constant term 2 - a(1) -> cos(x2pi) 3 - b(1) -> sin(x2pi) 4 - a(2) -> cos(2x2pi) 5 - b(2) -> sin(2x2pi) and so on for as many elements as in c OPTIONAL INPUT PARAMETERS: PHANG - phase angle of each observation, will be saved to common, if not provided will use the last values saved to common block. Angle is in degrees. KEYWORD INPUT PARAMETERS: OUTPUTS: f - Evaluated function value pder - (Optional) partial derivatives KEYWORD OUTPUT PARAMETERS: COMMON BLOCKS: lc_com - one variable, phang, that is used to save the phase angle from one call to the next in case of calling the lcfun or lcfunf from a canned routine that cannot be taught to pass the extra independent variable. SIDE EFFECTS: RESTRICTIONS: PROCEDURE: MODIFICATION HISTORY: 94/10/10, Written by Marc W. Buie, Lowell Observatory