Process Help

HISTOG - create a histogram file

 

Process Name

Menu Path

Link to Command Table

HISTOG

Report ribbon | Charts | Histogram File

Click here

 

Introduction

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.

Notes

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.

 


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

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


Error and Warning Messages

Message

Description

Solution

>>>  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.