; $Id: fith2.pro,v 1.2 2024/10/08 19:35:48 nathan Exp $ ; $Log: fith2.pro,v $ ; Revision 1.2 2024/10/08 19:35:48 nathan ; contents of SATPLOT_2.3.tar.gz ; ; Revision 2.3 2024/09/09 00:00:00 penteado ; Updating satplot package to V2.3 ;+ ; ; Name: fith2 ; ; Purpose: function to fit HI elongation tracks using Lugaz formula ; ; Parameters: X ; ; Keywords: - ; ; ; Called by fithm.pro ; ; ; History: May 2010/ update Feb 2011 ; 09 Sep 2024: updated documentation (penteado) ; ; Author: Christian Moestl ; Space Research Institute, Austrian Academy of Sciences ;- FUNCTION fith2, X common myfit2,xueber2,yueber2, dst, scnameueber degtorad=!dpi/180; b=X[0]; % constant angle beta measured FROM OBSERVER v=X[1]; % constant velocity t=xueber2-X[2]; (also deltat zur anfangszeit t0, die ja X[2] ist ;because of the acos the angle beta has to be positive if scnameueber eq 'A' then b=-b; ;my version a=((2*dst)/(v*t))-cos(b) c=sin(b) fit=-acos( (-c^2+a*sqrt((c^2)*(-1+a^2+c^2)))/(c*(a^2+c^2)) ) /degtorad sizey=size(yueber2) residue=double(0); for i=0,sizey(1)-1 do begin if finite(fit(i)) eq 0 then fit(i)=0 ;if NaNs make the residue very high (do this by setting values to zero) residue=residue+( abs(yueber2(i))-abs(fit(i)) )^2; ; residue=residue+( abs(yueber2(i)-fit(i)) )^2; endfor return, residue END