HISTOG Process

To access this process:

Display the Find Command screen, locate HISTOG and click Run.
Enter "HISTOG" into the Command Line and press <ENTER>.

See this process in the Command Table.

Process Overview

Generates a frequency histogram and a cumulative frequency histogram for any numeric field. The histogram file itself can be listed, showing the results of classifying the data into bins.

Note: Any sample value below @MINIMUM will be put into the bottom bin. Any sample value above @MINIMUM + @BINSIZE * @NUMBINS will be put into the top bin.

Input Files

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

Output Files

Name	I/O Status	Required	Type	Description
OUT	Output	Yes	Undefined	Output file. This will contain one record for each histogram bin and nine fields LOWER, MIDDLE, UPPER, FREQENCY, CUMFREQ., AVIVAL, FREQ-%, CUMF-%, TOTVAL.

Fields

Name	Description	Source	Required	Type	Default
VALUE	Field to be histogrammed (numeric).	IN	Yes	Numeric	Undefined

Parameters

Name	Description	Required	Default	Range	Values
BINSIZE	Bin width.	Yes	Undefined	Undefined	Undefined
MINIMUM	Lower bound of first bin.	Yes	Undefined	Undefined	Undefined
NUMBINS	Number of bins (max 50).	Yes	Undefined	1,50	Undefined
PRINT	>=1 display all records, all samples outside bins, the output file DD (0).	No	0	0,1	0,1

Example

!HISTOG &IN(SAMPLES),&OUT(HISTFILE),@BINSIZE=0.5,
       @MINIMUM=0.5,@NUMBINS=25

This creates the histogram file HISTFILE. A frequency plot may then be generated and displayed in the following way:

!PLOTHI &IN(HISTFILE),&PROTO(PLOTPROT),&PLOT(HIST.P),
        *X1(LOWER),*X2(UPPER),*Y(FREQENCY),
       @XMIN=0.5,@XMAX=13,@YMIN=0,@YMAX=100

!DISPLA &IN(HIST.P)

Note that the PLOTHI call assumes that the maximum frequency in any bin is 100. This may be checked using STATS1 on FREQENCY, if required.

Tip: The plot would also be improved with a frame (PLOTFR), not shown here.

Error and Warning Messages

Message	Description
>>> ERR 130 <<< ( fileno) IN HISTOG	Field *VALUE is not numeric. fileno is the internal file number of the &IN file. Fatal; the process is exited.
>>> ERR 131 <<< ( 0) IN HISTOG	An unsuitable parameter value has been specified. For example a negative bin width @BINSIZE or 0 for @NUMBINS. Fatal; the process is exited.
>>> WARNING - nnnn BINS REQUESTED >>> RESET TO MAXIMUM OF 500	An illegal value of @NUMBINS has been entered. The value is reset to the maximum of 500.