pro dorren, x, A, f, pder,ldstr=ldstr,ldspt=ldspt,rdns=rdns,$ photT=photT,spotT=spotT,wvl=wvl,_extra=e ;+ ;function dorren ; ; computes spot modulated stellar light curve using Dorren(1987) ; ;syntax ; curve = x, A, f, pder,ldstr=ldstr,ldspt=ldspt,rdns=rdns,$ ; photT=photT,spotT=spotT,wvl=wvl ; ;parameters ; x [INPUT;required] absissca points at which to compute spot ; model. These are angular displacements with respect to the ; initial spot longitude specified in A, in units of degrees. ; A [INPUT;required] spot parameters for dorrens model in ; radians where: ; a(0) = stellar inclination to LOS ; a(1) = spot latitude ; a(2) = spot size ; a(3) = initial spot longitude ; pder[OUTPUT] partial derivative with respect to each ; parameter in A ;keywords ; ldstr [INPUT] limb-darkening coefficient for star ; default = 0.32 Van Hamme(1994) ; ldspt [INPUT] limb-darkening coefficient for spot (umbra) ; rdns [INPUT] set this parameter if spot parameters and absissca are input ; in radians rather than degrees ; photT [INPUT] photospheric temperature in degrees Kelvin ; spotT [INPUT] spot temperature in degrees Kelvin ; wvl [INPUT] wavelength in nanometers ;subroutines ; MOD ; ;history ; liwei lin (Sep 03) better documentation/functionality than ; mod.pro. switch to modular ; (Jul 06) removed loop over longitudes and add pder ; (Aug 06) BUGFIX: note that T should be defined as: ; Pi - ATAN((-SIN(h(tmp)))*(TAN(b1(tmp)))) when B1>=Pi/2 ; ATAN((SIN(h(tmp)))*(TAN(b1(tmp)))) when B1