Process Help ST1GX - compute statistics including Sturgess's rule on one numeric field

 

Process Name	Menu Path	Link to Command Table
ST1GX	Sample Analysis ribbon | Statistics Processes | Sturgess Rule Statistics	Click here

 

• Introduction

• Files, Fields and Parameters

• Notes

• Example

• Errors

Introduction

Calculates general summary statistics for a single field, in log or non-log mode with or without class selection using Sturgess' Rule.

How to use

The calculated statistics include:-

• total number of records in the file.
• number of values used for statistical analysis.
• number of missing values.
• minimum, maximum, range, total and mean.
• variance, standard deviation and standard error.
• skewness and kurtosis.
• coefficient of variation.
• mean plus 2 and mean plus 4 standard deviations.
• median.
• mode.

These results are displayed in the Output control bar, and can be copied to the printer or printfile. A list of BIN sizes with BIN counts and percentage frequency for each class, cumulative frequency, class interval and number of BINS are also calculated. In addition, printer plots on a normal probability scale are calculated and can be sent to the printer or printfile.

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Files, Fields and Parameters

Input Files

Name	Description	I/O Status	Required	Type
IN	Input file.	Input	Yes	Table

Output Files

Name

I/O Status

Required

Type

Description

Fields

Name	Description	Source	Required	Type	Default
VALUE	Field for statistics.	IN	Yes	Numeric	Undefined

Parameters

Name	Description	Required	Default	Range	Values
BINSIZE	Bin width for histogram [computed].	No	Undefined	Undefined	Undefined
MINIMUM	Minimum bin limit [computed].	No	Undefined	Undefined	Undefined
STURGESS	Option Description 1 class interval [bin width] and minimum class value [bin limit] are calculated according to the following equation: Class interval = 1 + 3.3 log N [Sturgess Rule] and values within each bin are placed at the mid-point of each class (0).	No	0	0,1	0,1
LOGMODE	Option Description 1 log transformation [base 10] is calculated (0).	No	0	0,1	0,1
PERC	Option Description 0 numeric bin count for histogram; >0 percentage bin count for histogram (0).	No	0	Undefined	Undefined

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Notes

The first bin in the histogram plot contains all values up to MINIMUM. The last bin contains all values above the top value. If LOGMODE is set to 1, antilogs are automatically calculated.

Values of skewness and kurtosis calculated are interpreted as:

SKEWNESS	= 0. No distortion (Gaussian).
	> 0. Positive skew (to the right).
	< 0. Negative skew (to the left).
KURTOSIS	= 0. Mesokurtic (Gaussian).
	> 0. Leptokurtic (peaked).
	< 0. Platikurtic (flat).

 

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Example

!ST1GX

&IN(SEDREG),*VALUE(CU),@LOGMODE=1,@STURGESS=1

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Error and Warning Messages

Message	Description	Solution
>>> ERR 121 <<< ( fileno) IN STATS1	File read error. Fatal; the process is exited.	Check the range of values of the *VALUE field in the &IN file.
NO MODES DETECTED - CHECK CLASS INTERVAL	Error computing statistics (e.g. empty file). Fatal; the process is exited.	Check the range of values of the *VALUE field in the &IN file.

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