Using Wildcard Expressions

Wildcard expressions may be used in filtering the workfile display (see “Filtering the Workfile Display” ), in selected EViews commands, and in creating a group object.

For example, the following commands support the use of wildcards: show, store, fetch, copy, rename and delete.

To create a group using wildcards, simply select Object/New Object.../Group, and enter the expression, EViews will first expand the expression, and then attempt to create a group using the corresponding list of series. For example, entering the list,

y x*

will create a group comprised of Y and all series beginning with the letter X. Alternatively, you can enter the command:

group g1 x* y?? c

defines a group G1, consisting of all of the series matching “X*”, and all series beginning with the letter “Y” followed by two arbitrary characters.

When making a group, EViews will only select series objects which match the given name pattern and will place these objects in the group.

Once created, these groups may be used anywhere that EViews takes a group as input. For example, if you have a series of dummy variables, DUM1, DUM2, DUM3, …, DUM9, that you wish to enter in a regression, you can create a group containing the dummy variables, and then enter the group in the regression:

group gdum dum?

equation eq1.ls y x z gdum

will run the appropriate regression. Note that we are assuming that the dummy variables are the only series objects which match the wildcard expression DUM?.