region.confi.mean Function (GPL)

Syntax

region.confi.mean(<algebra>, <function>)

or 

region.confi.mean(<statistic function>, <function>)

<algebra>. Graph algebra, such as x*y. Refer to Brief Overview of GPL Algebra for an introduction to graph algebra.

<function>. One or more valid functions. These are optional. If no alpha function is specified, 0.95 is used for the alpha.

<statistic function>. Another statistic function. The result of the embedded statistic is used to calculate region.confi.mean.

Description

Calculates the confidence interval around the mean. The function creates two values. When using the interval, area, or edge graphic elements, this function results in one graphic element showing the range of the confidence interval. All other graphic elements result in two separate elements, one showing the confidence interval below the mean and one showing the confidence interval above the mean.

Examples

Figure 1. Example: Creating error bars
ELEMENT: interval(position(region.confi.mean(jobcat*salary)), shape(shape.ibeam))

Statistic Functions

See GPL Functions .