PRO oploterror, x, y, xerr, yerr, NOHAT=hat, HATLENGTH=hln, ERRTHICK=eth, $ ERRSTYLE=est, THICK = thick, NOCLIP=noclip, ERRCOLOR = ecol, Nsum = nsum,$ NSKIP=nskip, LOBAR=lobar, HIBAR=hibar, _EXTRA = pkey, ANONYMOUS_ = Dummy_ ;+ ; NAME: ; OPLOTERROR ; PURPOSE: ; Over-plot data points with accompanying X or Y error bars. ; EXPLANATION: ; For use instead of PLOTERROR when the plotting system has already been ; defined. ; ; CALLING SEQUENCE: ; oploterror, [ x,] y, [xerr], yerr, ; [ /NOHAT, HATLENGTH= , ERRTHICK =, ERRSTYLE=, ERRCOLOR =, ; /LOBAR, /HIBAR, NSKIP = , NSUM = , ... OPLOT keywords ] ; INPUTS: ; X = array of abcissae, any datatype except string ; Y = array of Y values, any datatype except string ; XERR = array of error bar values (along X) ; YERR = array of error bar values (along Y) ; ; OPTIONAL INPUT KEYWORD PARAMETERS: ; /NOHAT = if specified and non-zero, the error bars are drawn ; without hats. ; HATLENGTH = the length of the hat lines used to cap the error bars. ; Defaults to !D.X_VSIZE / 100). ; ERRTHICK = the thickness of the error bar lines. Defaults to the ; THICK plotting keyword. ; ERRSTYLE = the line style to use when drawing the error bars. Uses ; the same codes as LINESTYLE. ; ERRCOLOR = scalar integer (0 - !D.N_TABLE) specifying the color to ; use for the error bars ; NSKIP = Positive Integer specifying the error bars to be plotted. ; For example, if NSKIP = 2 then every other error bar is ; plotted; if NSKIP=3 then every third error bar is plotted. ; Default is to plot every error bar (NSKIP = 1) ; NSUM = Number of points to average over before plotting, default = ; !P.NSUM The errors are also averaged, and then divided by ; sqrt(NSUM). This approximation is meaningful only when the ; neighboring error bars have similar sizes. ; ; /LOBAR = if specified and non-zero, will draw only the -ERR error bars. ; /HIBAR = if specified and non-zero, will draw only the +ERR error bars. ; If neither LOBAR or HIBAR are set _or_ if both are set, ; you will get both error bars. Just specify one if you ; only want one set. ; Any valid keywords to the OPLOT command (e.g. PSYM, YRANGE) are also ; accepted by OPLOTERROR via the _EXTRA facility. ; ; NOTES: ; If only two parameters are input, they are taken as Y and YERR. If only ; three parameters are input, they will be taken as X, Y and YERR, ; respectively. ; ; EXAMPLE: ; Suppose one has X and Y vectors with associated errors XERR and YERR ; and that a plotting system has already been defined: ; ; (1) Overplot Y vs. X with both X and Y errors and no lines connecting ; the points ; IDL> oploterror, x, y, xerr, yerr, psym=3 ; ; (2) Like (1) but overplot only the Y errors bars and omits "hats" ; IDL> oploterror, x, y, yerr, psym=3, /NOHAT ; ; (3) Like (2) but suppose one has a positive error vector YERR1, and ; a negative error vector YERR2 (asymmetric error bars) ; IDL> oploterror, x, y, yerr1, psym=3, /NOHAT,/HIBAR ; IDL> oploterror, x, y, yerr2, psym=3, /NOHAT,/LOBAR ; ; PROCEDURE: ; A plot of X versus Y with error bars drawn from Y - YERR to Y + YERR ; and optionally from X - XERR to X + XERR is written to the output device ; ; WARNING: ; This an enhanced version of the procedure OPLOTERR in the standard RSI ; library. It was renamed to OPLOTERROR in June 1998 in the IDL ; Astronomy library. ; ; MODIFICATION HISTORY: ; Adapted from the most recent version of PLOTERR. M. R. Greason, ; Hughes STX, 11 August 1992. ; Added COLOR keyword option to error bars W. Landsman November 1993 ; Add ERRCOLOR, use _EXTRA keyword, W. Landsman, July 1995 ; Remove spurious call to PLOT_KEYWORDS W. Landsman, August 1995 ; OPLOT more than 32767 error bars W. Landsman, Feb 1996 ; Added NSKIP keyword W. Landsman, Dec 1996 ; Added HIBAR and LOBAR keywords, M. Buie, Lowell Obs., Feb 1998 ; Rename to OPLOTERROR W. Landsman June 1998 ; Converted to IDL V5.0 W. Landsman June 1998 ; Ignore !P.PSYM when drawing error bars W. Landsman Jan 1999 ; Handle NSUM keyword correctly W. Landsman Aug 1999 ; Check limits for logarithmic axes W. Landsman Nov. 1999 ; Work in the presence of NAN values W. Landsman Dec 2000 ; Improve logic when NSUM or !P.NSUM is set W. Landsman Jan 2001 ; Remove NSUM keyword from PLOTS call W. Landsman March 2001 ; Only draw error bars with in XRANGE (for speed) W. Landsman Jan 2002 ; Fix Jan 2002 update to work with log plots W. Landsman Jun 2002 ;- ; Check the parameters. ; On_error, 2 np = N_params() IF (np LT 2) THEN BEGIN print, "OPLOTERR must be called with at least two parameters." print, "Syntax: oploterr, [x,] y, [xerr], yerr, [..oplot keywords... " print,' /NOHAT, HATLENGTH = , ERRTHICK=, ERRSTLYE=, ERRCOLOR=' print,' /LOBAR, /HIBAR, NSKIP= ]' RETURN ENDIF ; Error bar keywords (except for HATLENGTH; this one will be taken care of ; later, when it is time to deal with the error bar hats). IF (keyword_set(hat)) THEN hat = 0 ELSE hat = 1 if not keyword_set(THICK) then thick = !P.THICK IF (n_elements(eth) EQ 0) THEN eth = thick IF (n_elements(est) EQ 0) THEN est = 0 IF (n_elements(ecol) EQ 0) THEN ecol = !P.COLOR if N_elements( NOCLIP ) EQ 0 THEN noclip = 0 if not keyword_set(NSKIP) then nskip = 1 if N_elements(nsum) EQ 0 then nsum = !P.NSUM if not keyword_set(lobar) and not keyword_set(hibar) then begin lobar=1 hibar=1 endif else if keyword_set(lobar) and keyword_set(hibar) then begin lobar=1 hibar=1 endif else if keyword_set(lobar) then begin lobar=1 hibar=0 endif else begin lobar=0 hibar=1 endelse ; ; If no X array has been supplied, create one. Make sure the rest of the ; procedure can know which parameter is which. ; IF np EQ 2 THEN BEGIN ; Only Y and YERR passed. yerr = y yy = x xx = indgen(n_elements(yy)) xerr = make_array(size=size(xx)) ENDIF ELSE IF np EQ 3 THEN BEGIN ; X, Y, and YERR passed. yerr = xerr yy = y xx = x ENDIF ELSE BEGIN ; X, Y, XERR and YERR passed. yy = y g = where(finite(xerr)) xerr[g] = abs(xerr[g]) xx = x ENDELSE g = where(finite(yerr)) yerr[g] = abs(yerr[g]) ; ; Determine the number of points being plotted. This ; is the size of the smallest of the three arrays ; passed to the procedure. Truncate any overlong arrays. ; n = N_elements(xx) < N_elements(yy) IF np GT 2 then n = n < N_elements(yerr) IF np EQ 4 then n = n < N_elements(xerr) xx = xx[0:n-1] yy = yy[0:n-1] yerr = yerr[0:n-1] IF np EQ 4 then xerr = xerr[0:n-1] ; If NSUM is greater than one, then we need to smooth ourselves (using FREBIN) if NSum GT 1 then begin n1 = float(n) / nsum n = long(n1) xx = frebin(xx, n1) yy = frebin(yy, n1) yerror = frebin(yerr,n1)/sqrt(nsum) if NP EQ 4 then xerror = frebin(xerr,n1)/sqrt(nsum) endif else begin yerror = yerr if NP EQ 4 then xerror = xerr endelse ylo = yy - yerror*lobar yhi = yy + yerror*hibar if Np EQ 4 then begin xlo = xx - xerror*lobar xhi = xx + xerror*hibar endif ; ; Plot the positions. ; if n NE 1 then begin oplot, xx, yy, NOCLIP=noclip,THICK = thick,_EXTRA = pkey endif else begin plots, xx, yy, NOCLIP=noclip,THICK = thick,_EXTRA = pkey endelse ; ; Plot the error bars. Compute the hat length in device coordinates ; so that it remains fixed even when doing logarithmic plots. ; data_low = convert_coord(xx,ylo,/TO_DEVICE) data_hi = convert_coord(xx,yhi,/TO_DEVICE) if NP EQ 4 then begin x_low = convert_coord(xlo,yy,/TO_DEVICE) x_hi = convert_coord(xhi,yy,/TO_DEVICE) endif ycrange = !Y.CRANGE & xcrange = !X.CRANGE if !Y.type EQ 1 then ylo = ylo > 10^ycrange[0] if (!X.type EQ 1) and (np EQ 4) then xlo = xlo > 10^xcrange[0] sv_psym = !P.PSYM & !P.PSYM = 0 ;Turn off !P.PSYM for error bars ; Only draw error bars for X values within XCRANGE if !X.TYPE EQ 1 then xcrange = 10^xcrange g = where((xx GT xcrange[0]) and (xx LE xcrange[1]), Ng) if (Ng GT 0) and (Ng NE n) then begin istart = min(g, max = iend) endif else begin istart = 0L & iend = n-1 endelse FOR i = istart, iend, Nskip DO BEGIN plots, [xx[i],xx[i]], [ylo[i],yhi[i]], LINESTYLE=est,THICK=eth, $ NOCLIP = noclip, COLOR = ecol ; Plot X-error bars ; if np EQ 4 then $ plots, [xlo[i],xhi[i]],[yy[i],yy[i]],LINESTYLE=est, $ THICK=eth, COLOR = ecol, NOCLIP = noclip IF (hat NE 0) THEN BEGIN IF (N_elements(hln) EQ 0) THEN hln = !D.X_VSIZE/100. exx1 = data_low[0,i] - hln/2. exx2 = exx1 + hln if lobar then $ plots, [exx1,exx2], [data_low[1,i],data_low[1,i]],COLOR=ecol, $ LINESTYLE=est,THICK=eth,/DEVICE, noclip = noclip if hibar then $ plots, [exx1,exx2], [data_hi[1,i],data_hi[1,i]], COLOR = ecol,$ LINESTYLE=est,THICK=eth,/DEVICE, noclip = noclip ; IF np EQ 4 THEN BEGIN IF (N_elements(hln) EQ 0) THEN hln = !D.Y_VSIZE/100. eyy1 = x_low[1,i] - hln/2. eyy2 = eyy1 + hln if lobar then $ plots, [x_low[0,i],x_low[0,i]], [eyy1,eyy2],COLOR = ecol, $ LINESTYLE=est,THICK=eth,/DEVICE, NOCLIP = noclip if hibar then $ plots, [x_hi[0,i],x_hi[0,i]], [eyy1,eyy2],COLOR = ecol, $ LINESTYLE=est,THICK=eth,/DEVICE, NOCLIP = noclip ENDIF ENDIF NOPLOT: ENDFOR !P.PSYM = sv_psym ; RETURN END