Warnings can occur during evaluation, for example when trying to take the square root of a negative number, for example:
This Warning dialog gives you the option to ignore this and future warnings. If you select Ignore Warnings, Y yields:
Y → [NAN, NAN, 0, 1, 1.414]
The NaN values can be propagated further into a model.
Analytica displays warning conditions detected while evaluating an expression only if the resulting value assigned to a variable contains an explicit error. In the following example, the
NAN resulting from evaluating Sqrt(X) for negative
X does not appear in the result, so it does not display a warning:
X < 0) evaluates to an array containing both
True (1) and
False (0) values, the expression evaluates
Sqrt(X), and generates
NAN as for
Y above. But, the conditional means that resulting value for
Z contains no
NANs, and so Analytica generates no warning when
Z is evaluated.
You can also make use of the return value, even if it might be errant, as in the following example:
The common warning “subscript or slice value out of range” returns
Null, for example:
Index I := 1..5
X[I = 6] → Null
If you want to ignore warnings for a single variable, you can use the IgnoreWarnings() function around the definition.