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(gnuplot.info)errorbars

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Enter node , (file) or (file)node

 Error bars are supported for 2-d data file plots by reading one to four
 additional columns (or `using` (Note: using ) entries); these additional
 values are used in different ways by the various errorbar styles.

 In the default situation, `gnuplot` (Note: gnuplot ) expects to see three,
 four, or six numbers on each line of the data file---either

       (x, y, ydelta),
       (x, y, ylow, yhigh),
       (x, y, xdelta),
       (x, y, xlow, xhigh),
       (x, y, xdelta, ydelta), or
       (x, y, xlow, xhigh, ylow, yhigh).

 The x coordinate must be specified.  The order of the numbers must be
 exactly as given above, though the `using` qualifier can manipulate the order
 and provide values for missing columns.  For example,

       plot 'file' with errorbars
       plot 'file' using 1:2:(sqrt($1)) with xerrorbars
       plot 'file' using 1:2:($1-$3):($1+$3):4:5 with xyerrorbars

 The last example is for a file containing an unsupported combination of
 relative x and absolute y errors.  The `using` entry generates absolute x min
 and max from the relative error.

 The y error bar is a vertical line plotted from (x, ylow) to (x, yhigh).
 If ydelta is specified instead of ylow and yhigh, ylow = y - ydelta and
 yhigh = y + ydelta are derived.  If there are only two numbers on the record,
 yhigh and ylow are both set to y.  The x error bar is a horizontal line
 computed in the same fashion.  To get lines plotted between the data points,
 `plot` (Note: plot ) the data file twice, once with errorbars and once with
 lines (but remember to use the `notitle` option on one to avoid two entries in
 the key).

 The error bars have crossbars at each end unless `set bar` (Note: bar ) is
 used (see set bar` for details).

 If autoscaling is on, the ranges will be adjusted to include the error bars.

 See `plot using`, `plot with` (Note: with ), and  `set style`
 (Note: style ) for more information.