# Error Message Types

There are several types of error messages in Analytica. Many messages are designed to inform you that something in the model needs to be corrected; some messages indicate that Analytica cannot continue or complete your request. Each error message begins with its message type, one of warning, lexical, syntax, evaluation, system, and fatal errors. In general, Analytica allows you to continue working on your model unless it cannot proceed until a problem has been corrected. When you are editing a variable definition, you can request an error message by pressing Alt-Enter or by clicking the definition warning icon

## Warning

A warning indicates that there is a possible problem. Here is an example.

A warning is reported during result evaluation to inform you that continuing can yield unexpected results.

You can suppress evaluation warnings for all variables by disabling the Show result warnings preference (see Preferences dialog). When Show result warnings is unchecked, any warning conditions encountered during result evaluation is ignored. You can also suppress warnings during evaluation of a single expression with the IgnoreWarnings() function.

If an identifier in a module you are adding to a model has a name conflict with an identifier in the model, you see a warning similar to the following.

## Lexical error

A lexical error occurs when part of an expression is missing or is invalid. For example, if you enter a number with an invalid number suffix, you might get a message like this:

## Syntax error

A syntax error occurs when an expression contains a syntax mistake. Analytica often reports the mistake together with the fragment of the expression that contained the error. Here is an example.

These are two common syntax errors in a call to a function:

Expecting ","
Indicates a comma is missing, or there are too few parameters to a function.
Expecting ")"
Indicates there are too many parameters to a function.

If you try to change an identifier of an object to an identifier already in use, you get a message like this:

## Evaluation error

An evaluation error occurs when there is a problem while evaluating a variable, user-defined function, or system function. It asks if you want to edit the definition of the variable being evaluated.

If a system function find the parameter is not what it expects, it shows an error message like this:

This message indicates that a parameter to a function is of the wrong type. You might need to redefine the variable or expression being passed as a parameter:

## Invalid number

If a calculation tries to perform a division by zero, it displays a warning with an option to continue calculating. Three possible error codes can be returned as a result of an invalid calculation.

Code Meaning
INF Infinity, such as 1/0.
NAN An indeterminant number. Results from invalid functions such as Sqrt(-1), or 0/0.
Null

(blank)

Displays as a blank cell if the result is a table, or shows the Compute button otherwise.

Results from certain functions, such as SubIndex(), when a result is not available.

You can test for these results in an expression using X = INF, IsNan(X), or X = Null. See also Null.