IRIS Toolbox Reference Manual

!log_variables

List of log-linearised variables

Syntax

!log_variables
    VariableName, VariableName, 
    VariableName, ...

Syntax with inverted list

!log_variables
    !all_but
    VariableName, VariableName, 
    VariableName, ...

Syntax with regular expression(s)

!log_variables
    VariableName, VariableName, 
    VariableName, ...
    <REGEXP>, <REGEXP>, ...

Description

List all log variables under this headings. Only measurement or transition variables can be declared as log variables.

In non-linear models, all variables are linearised around the steady state or a balanced-growth path. If you wish to log-linearise some of them instead, put them on a !log_variables list. You can also use the !all_but keyword to indicate an inverse list: all variables will be log-linearised except those listed.

To create the list of log variables, you can also use regular expressions, each enlosed in a pair of angle brackets, < and >. All measurement and transition variables whose names match one of the regular expressions will be declared as log variables. See also help on regular expressions in the Matlab documentation.

Example

The following block of code will cause the variables Y, C, I, and K to be declared as log variables, and hence log-linearised in the model solution, while r and pie will be linearised:

!transition_variables
    Y, C, I, K, r, pie

!log_variables
    Y, C, I, K

You can do the same job by writing

!transition_variables
    Y, C, I, K, r, pie

!log_variables
    !all_but
    r, pie

Example

We again achieve the same result as above, but now using a regular expression.

!transition_variables
    Y, C, I, K, r, pie

!log_variables
    <[A-Z]\w*>

The regular expression [A-Z]\w* selects all variables whose names start with an upper-case letter. Hence, again the variables Y, C, I, and K will be declared as log variables.