##
ERRPLOT

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.

###
Calling Sequence

ERRPLOT, ```
[ X, ] Low, High
```

###
Arguments

####
X

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.

####
Low

A vector of lower estimates, equal to data - error.

####
High

A vector of upper estimates, equal to data + error.

###
Keywords

####
WIDTH

The width of the error bars. The default is 1% of plot width.

###
Examples

To plot symmetrical error bars where Y is a vector of data values and ERR is a symmetrical error estimate, enter:

PLOT, Y

ERRPLOT, Y-ERR, Y+ERR

If error estimates are non-symmetrical, provide actual error estimates in the *
upper*
and *
lower*
arguments.

PLOT,Y

ERRPLOT, lower, upper

To plot versus a vector of abscissas:

PLOT, X, Y

ERRPLOT, X, Y-ERR, Y+ERR