;+ ----------------------------------------------------------------------- ; ROUTINE: vnorm ; PURPOSE: determines the norm of a vector ; ; AUTHOR DATE DESCRIPTION OF CHANGE ; ------ ---- --------------------- ; M Brittnacher 11/22/97 orginal code ; ;- ----------------------------------------------------------------------- FUNCTION vnorm,v RETURN, SQRT(TOTAL(v*v,/DOUBLE)) END ;+ ----------------------------------------------------------------------- ; ROUTINE: unit_vec ; PURPOSE: converts a vector to a unit vector ; ; AUTHOR DATE DESCRIPTION OF CHANGE ; ------ ---- --------------------- ; M Brittnacher 11/22/97 orginal code ; ;- ----------------------------------------------------------------------- FUNCTION unit_vec,v vmag = vnorm(v) IF (vmag NE 0) THEN BEGIN uvec = v/vmag ENDIF ELSE BEGIN uvec = 0.0*v ENDELSE RETURN, uvec END ;+ ----------------------------------------------------------------------- ; ROUTINE: dot_product ; PURPOSE: performs a dot product of two vectors ; ; AUTHOR DATE DESCRIPTION OF CHANGE ; ------ ---- --------------------- ; M Brittnacher 11/22/97 orginal code ; ;- ----------------------------------------------------------------------- FUNCTION dot_product,u,v RETURN, TOTAL(u*v,/DOUBLE) END