;+
; Overplots a box from xstart to xend, with uper and lower bounds the
; mean + sigma and mean - sigma of the yarray passed in
;
; @param xstart {in}{required}{type=long} where box starts in yarray
; @param xend {in}{required}{type=long} where box ends in yarray
; @param yarray {in}{required}{type=array} data array for rms box
;-
pro rmsbox, xstart, xend, yarray
    compile_opt idl2
    
    if (n_params() ne 3) then begin
        message,'Usage: rmsbox, xstart, xend, yarray',/info
        return
    endif
    if xstart gt xend then begin
        tmp = xend
        xend = xstart
        xstart = tmp
    endif
    
    meany = mean(yarray[xstart:xend])
    sigmay = sigma(yarray[xstart:xend])
    
    box = [[xstart,meany+sigmay],[xend,meany+sigmay],[xend,meany-sigmay],[xstart,meany-sigmay]]
    
    ; plot this box, starting at the top, left-hand corner and going clockwise
    gbtoplot,[box[0,0],box[0,1]],[box[1,0],box[1,1]],color=!cyan, /chan
    gbtoplot,[box[0,1],box[0,2]],[box[1,1],box[1,2]],color=!cyan, /chan
    gbtoplot,[box[0,2],box[0,3]],[box[1,2],box[1,3]],color=!cyan, /chan
    gbtoplot,[box[0,3],box[0,0]],[box[1,3],box[1,0]],color=!cyan, /chan

end