pro xform_redden,colin,xformsav,colout ; this routine transforms the reddening vector array colin according ; to the set of linear transformation coefficients found in file xformsav, ; containing data written by m67_color_fit, ; and returns the transformed reddenings in colout. ; Requires 9 colors: u-g, g-r, r-i, i-z, z-J, J-H, H-K, g-Gred, g-D51 ; The algebra behind this is: ; xform_color computes transformed stellar colors as ; ; c'* = c* + aa + bb*(g*-r* - 0.5) ; ; If c* is reddened by delta(c) before the transformation then ; ; c'* = c* + aa + bb*(g*-r* - 0.5) + delta(c) + bb*(delta(g-r)) restore,xformsav xx=colin(1,*) colout=colin for i=0,8 do begin colout(i,*)=colout(i,*)+bb(i)*xx endfor end