# Objects and Their Attributes - Part 3 of 3

## Current Objects

A Current object is the last object to be brought to Analytica’s attention. If you type a command without specifying a parameter, Analytica will assume by default that you are referring to the current object, as illustrated below:

Example>show Mpy (You do a "show" on variable Mpy.)
variable Mpy
Title: miles per year
Units: Miles/year
Description: Annual mileage driven
Definition: 12K
Nodelocation: 208,48
Nodesize: 52,24
Example>title (You ask to see the Title of the current object.)'
miles per year (This is the Title of Mpy.)
Example>

## Modifying Attributes

You may add an attribute to an object, or replace an already assigned attribute, by typing the attribute to be added or replaced, the identifier of the object, a colon (":") and a new value or text string. For example, to change the title of variable Mpy:

Example>title mpy: mileage (You replace the Title.)
Example>title (You ask to see the new Title for Mpy.)
mileage
Example>title:miles per year (Original Title restored.)
Example>title
miles per year
Example>

You can add or replace only user-specified attributes, not computed attributes. To add or replace a definition of a variable (or another object), you type the identifier of the variable, a ":", and a new definition (you do not need to type the word "definition"). For example:

Example>mpy: 20K

is equivalent to:

Example>Definition mpy: 20K

If you include the identifiers of new objects in the definition of another object, Analytica will suggest creating them.

## Deleting Objects

The Delete command allows you to remove variables from a model. You cannot undo a Delete command. Analytica will automatically update outputs of the object to be deleted so that they no longer reference the object.

## List Command

To see a list of all objects that belong to a particular class, you use the List command. For instance:

Example>list sysfunction
Abs Arctan Array Average Beta
Chance Choose Cinterval Concat Correlation
Cos Cumulate Cumulative Density Dydx
Dynamic Elasticity Exp Fixarray Fractiles
Getfract If0 Ifpos Infromrec Linear
Ln Lognormal Makerect Max Maxev
Mean Mid Min Normal Pred
Product Rank Rankcorrel Reform Repeat
Round Sample Sdeviation Sequence Sin
Size Slice Sqr Sqrt Subscript
Sum Table Uncumulate Uniform Variance

## Objects and Attributes: Summary

Commands and other specific object identifiers are in bold. Generic objects, such as Class class or object o, are in italic:

Show o
To list all of the user-specified attributes of an object.

Allshow
To display all of the user-specified objects in a model.

class new-identifier To create a new user-specified object (i.e., a variable, model, attribute, or function).

o
To list a summary of an object, you type its identifier.

attribute o
To display a particular attribute of an object, you type the attribute and the identifier of the object to be displayed. If you do not type an object after the attribute, Analytica will assume the current object.

attribute o:text
To change an attribute of a particular object. If you do not type an object after the attribute, Analytica will assume the current object.

var:x
To change the definition of a variable, you type its identifier, a colon, and a new definition.

Delete o
To delete an object.

List class
To see all of the objects of a particular class.

Profile o
Command to display all the attributes of an object o (both user-specified and computed). Primarily of interest to system developers.

Concepts:

object
An entity that Analytica recognizes.

User-Created object
An object that you create (e.g., a variable, model, attribute, function, or version).

System object
An object that Analytica supplies (e.g., a command, sysfunction, keyword, sysvariable, or kind). The user cannot create system objects.

attribute
A property of an object. For instance, variables have four attributes: a Title, Units, Description, and Definition.

Computed attribute
An attribute that Analytica computes automatically (i.e., Date, Modauthor, Inputs, outputs, Value, Probvalue, or Contains).

User Interface attribute
An attribute that Analytica computes using visual or other information in the user interface (i.e., Location, Nodesize, Windstate, NodeColor etc.).

Class
A category of object, such as command or variable.