function shiftcube,incube,q,vpeakpt,vdisppt,offsetpt,res,v0,dv0

;------------------------------------
; Trims a datacube to contain the appropriate sections of the
; spectrum for analysis, thereby communicating the lag effects.
;------------------------------------
;used by the more advanced SCF routines to analyze the lag parameter

dimen=size(incube)

output=fltarr(dimen(1),dimen(2),2*q*vdisppt+1)
for a=0,dimen(1)-1 do begin
for b=0,dimen(2)-1 do begin
inspec=incube(a,b,*)

;vpeakpt=round((inparams(a,b)-v0)/dv0)
output(a,b,*)=(inspec(vpeakpt-q*vdisppt+offsetpt:vpeakpt $
	+q*vdisppt+offsetpt));,q*vdisppt,/edge_truncate)
endfor
endfor

return,output
end