Single Variable Histogram

Navigation: Models ➔ Statistical Models ➔ Single Variable Histogram

Flow Statistics	General Statistics	Single Variable Histogram	Bivariate Statistics

---

General Description

This model is used in Dynamic Simulation only.

The Single Variable Histogram can be used to calculate and display statistical information about one variable.

1. The Histogram graphic can be displayed by holding down the shift key and left mouse clicking on the Single Variable Histogram graphical symbol.
2. From the menu, select "Histogram" and place on the flowsheet. See example below:

Data Sections

The default sections and variable names are described in detail in the following tables. The default Single Variable Histogram access window consists of 2 sections. This number may increase or decrease, based on user configuration.

Summary of Data Sections

1. SingleVarStats tab - Contains general information relating to the unit.
2. Histogram tab - The second tab has data related to displaying the data in a histogram.
3. Info tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.

Single Variable Histogram Page

Unit Type: SingleVarStats - The first tab page in the access window will have this name.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
Tag	Display	This name tag may be modified with the change tag option.
Condition	Display	OK if no errors/warnings, otherwise lists errors/warnings.
ConditionCount	Display	The current number of errors/warnings. If condition is OK, returns 0.
GeneralDescription / GenDesc	Display	This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the UnitType or SubClass.
Requirements
On	Tick box	When ticked, the model will log data and perform calculations.
StatTag	Input	The tag which will be logged, graphed and calculations performed on its values.
Reset	Button	This will reset the calculations and histogram.
Histogram_Minimum / HistoMin	Input	The minimum value to be shown on the histogram. Any values lower than this will be shown as a single bar on the histogram.
Histogram_Maximum / HistoMax	Input	The maximum value to be shown on the histogram. Any values higher than this will be shown as a single bar on the histogram.
Histogram_Buckets / HistoCount	Input	The number of intervals to be shown on the histogram. This excludes the bar for values which are under the specified minimum and the bar for values which are over the specified maximum.
Graph_Units	List	The units to be used on the histogram. This list will change depending on the tag chosen for StatTag.
Average / Avg	Calc	The average of the logged values of the specified tag since the model was last reset.
Standard_Deviation / StdDev	Calc	The standard deviation of the logged values of the specified tag since the model was last reset.
Minimum / Min	Output	The minimum value of the specified tag since the model was last reset.
Maximum / Max	Output	The maximum value of the specified tag since the model was last reset.
Number_Of_Records / N	Output	The number of values of the specified tag logged since the model was last reset.

Histogram tab

The Histogram tab page provides a list of the values used to create the histogram.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
RecordsSinceHistoReset / RSHR	Output	The number of values (records) of the specified tag logged since the model (histogram) was last reset.
Buckets.[Bucket Number]...
The buckets are simply the intervals on the histogram. The number of buckets = Histogram_Buckets + 2
Count	Output	The number of values which fit into this bucket/interval.

Note: If the value of the stattag is not a number (NAN) (shown as a "*"), then this will be counted as outside the range and put into the last bucket/interval.

Adding this Model to a Project

Add to Configuration File

Sort either by DLL or Group:

	DLL:	ControlDyn.dll	→	Units/Links	→	Statistics: Single Variable Histogram
or	Group:	General	→	Units/Links	→	Statistics: Single Variable Histogram

See Model Selection for more information on adding models to the configuration file.

Insert into Project Flowsheet

Insert Unit

→

Statistics

→

Single Variable Histogram

See Insert Unit for general information on inserting units.

Example Project

• Waste Handling with Batch Digestion Example Project