make_vect_sph.pro (Kronos IDL library)

;+
; Contains the make_vect_sph function
;
; :Author:
;    Baptiste Cecconi
;
; :History:
;    2004/12/03: Created
;
;    2004/12/03: Last Edit
;-
;
;+
; make_vect_sph is a function that <behavior desc here>
;
; :Returns:
;    <return desc here>
;
; :Params:
;    h_in:  in, required, type=sometype
;       A parameter named h_in
;    th_in: in, required, type=sometype
;       A parameter named th_in
;    ph_in: in, required, type=sometype
;       A parameter named ph_in
;
; :Keywords:
;    deg:   in, optional, type=sometype
;       A keyword named deg
;-
FUNCTION make_vect_sph,h_in,th_in,ph_in,deg=deg
	
	h = double([h_in])
	th = double([th_in])    
	ph = double([ph_in])

	sh = size(h)
	sth = size(th)
	sph = size(ph)
	
	nh = sh(1)
	nth = sth(1)
	nph = sph(1)

	err = bytarr(4)
	err(0) = sh(0) ne 1
	err(1) = sth(0) ne 1
	err(2) = sph(0) ne 1
	err(3) = ((nh-nth)*(nh-1)*(nth-1) + (nh-nph)*(nh-1)*(nph-1) + $
		(nth-nph)*(nth-1)*(nph-1)) ne 0

	if (where(err))(0) ne -1 then begin
		print,"MAKE_VECT_SPH: error, wrong argument size..."
		if err(0) then print," > length must a scalar (1) or a vector (n)"
		if err(1) then print," > colat. must a scalar (1) or a vector (n)"
		if err(2) then print," > azimuth must a scalar (1) or a vector (n)"
		if err(3) then print," > in case of vectors, argument must have same dimensions (n or 1)"
		return,-1
	endif

	if keyword_set(deg) then begin
		th=th/!radeg & ph=ph/!radeg 
	endif
	nv = max([nh,nth,nph])
	vect = dblarr(3,nv)
	h = rebin(reform(h,1,nh),3,nv)
	th = rebin(reform(th,1,nth),1,nv)
	ph = rebin(reform(ph,1,nph),1,nv)

	vect = h*[cos(ph)*sin(th),sin(th)*sin(ph),cos(th)]
	return,vect
	end