Custom discrete probabilities

Analytica User GuideProbability DistributionsCustom discrete probabilities

These functions let you specify a discrete probability distribution using a custom set of values, text (label) values, or numbers.

Probtable(): Probability Tables

To describe a probability distribution on a discrete variable whose domain is a list of numbers or list of labels, you use special kind of edit table called a probability table (or probtable) (see [[Arrays and Indexes).

Create a probability table: To define a variable using a probability table:

1. Determine the variable’s domain — number or labels for its possible values.
2. Select the variable and view its definition attribute in the Object window or Attribute panel (page 20) of the Diagram window.
3. Press the expr menu above the definition field and select Probability Table.

1. If the variable already has a definition, it confirms that you wish to replace it.

   Tip

   If the definition of a variable is already a probability table, a ProbTable button appears in the definition. Click it to open the Edit Table window (see “Defining a variable as an edit table”).

1. The Indexes dialog opens to confirm your choices for the indexes of the table. It already includes the selected variable (Self) among the selected indexes. Other options are variables with a domain that is a list of numbers or list of labels. Add or remove any other variables that you want to condition this variable on.

Tip

Self is required as an index of a probability table. It refers to the domain (possible values) of this variable.

See Also

The domain attribute and discrete variablesCustom discrete probabilitiesParametric continuous distributions