ZTest_conf - script and chart function
ZTest_conf() returns the aggregated z value for a series of values.
If the function is used in the load script, the values are iterated over a number of records as defined by a group by clause.
If the function is used in a chart expression, the values are iterated over the chart dimensions.
Syntax:
ZTest_conf(value[, sigma[, sig]])
Return data type: numeric
Arguments:
- value: The sample values to be evaluated. A population mean of 0 is assumed. If you want the test to be performed around another mean, subtract that mean from the sample values.
- sigma: If known, the standard deviation can be stated in sigma. If sigma is omitted the actual sample standard deviation will be used.
- sig: The two-tailed level of significance can be specified in sig. If omitted, sig is set to 0.025, resulting in a 95% confidence interval.
Limitations:
Text values, NULL values and missing values in the expression value will result in the function returning NULL.
Example:
ZTest_conf(Value-TestValue)