The ERRPLOT procedure plots error bars over a previously drawn plot.
This routine is written in the IDL language. Its source code can be found in the file
errplot.pro in the
lib subdirectory of the IDL distribution.
ERRPLOT, [ X, ] Low, High [, WIDTH=value]
A vector containing the abscissa values at which the error bars are to be plotted. X only needs to be provided if the abscissa values are not the same as the index numbers of the plotted points.
A vector of lower estimates, equal to data - error.
A vector of upper estimates, equal to data + error.
The width of the error bars. The default is 1% of plot width.
To plot symmetrical error bars where Y is a vector of data values and ERR is a symmetrical error estimate, enter:
; Plot data: PLOT, Y ; Overplot error bars: ERRPLOT, Y-ERR, Y+ERR
If error estimates are non-symmetrical, provide actual error estimates in the upper and lower arguments.
; Plot data: PLOT,Y ; Provide custom lower and upper bounds: ERRPLOT, lower, upper
To plot Y versus a vector of abscissas:
; Plot data (X versus Y): PLOT, X, Y ; Overplot error estimates: ERRPLOT, X, Y-ERR, Y+ERR
OPLOTERR, PLOT, PLOTERR