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

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.


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


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).

 


Example

!ST1GX

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


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.