User Guide

Chapter 7 Creating Charts from Data 149
3 From the second pop-up menu, choose the kind of error bar you want to display:
Fixed Value: Displays an error bar of the same absolute value for every data point.
Specify a value in the adjacent eld.
Percentage: Displays error bars based on a xed percentage of each data point value.
Specify a percentage in the adjacent eld.
Standard Deviation: Displays error bars based on the standard deviation of your data
set. Specify the number of standard deviations in the adjacent eld.
Standard Error: Displays standard error bars.
Custom: Lets you set error bars based on your own criteria. In the Positive eld, specify
how far above the data points you want the error bars to extend; in the Negative eld,
specify how far below the data points you want the error bars to extend.
4 In the eld adjacent to the second pop-up menu, specify the error bar range.
5 Select an error bar, click the Graphic inspector button, and optionally change the error
bar line ends using the Stroke pop-up menu.
Showing Trendiness in Charts
Trendlines are lines calculated and drawn to t your data, according to the type of
equation you prefer. You can display trendlines for most 2D charts, except stacked bar,
column, area, and pie charts.
To show a trendline for the data points in a selected series:
1 Select one or more series for which you want to show a trendline, and then click the
Inspector button in the toolbar.
2 Click Chart in the Inspector window, and then click Series.
3 Click Advanced at the bottom of the Series pane. Then click Trendline.
4 From the pop-up menu, choose the type of equation you want to use to calculate the
trendline:
Linear: Produces a best-t straight line, most useful for simple, linear data series.
Logarithmic: Produces a best-t curved line, most useful when values increase or
decrease quickly, then level out.