Unexpected Results

The calculator can output certain results that may be unexpected by the user. Some of the more common cases are described below.

NaN

A value of "NaN" in the results area means that the result is not a number. This can happen when there is a divide by zero somewhere in a calculation or some other invalid condition.

Undefined

An Undefined output can pop up when the user is creating a function block with an In statement and that function block has not been executed yet. This is normal.

Error Messages

There are two types of error messages that can pop up in the program:

User Error Messages

These error messages indicate that incorrect values were used in a calculation. For instance, there may not be enough entries on the stack, or a value may be of a different type than required in the calculation. If this sort of message pops up, fix the entries on the stack and try the operation again.

Programming Error Messages

These error messages indicate that something unexpected went wrong with the program. One of these messages may mean that something in the calculator should be fixed or the developer failed to anticipate an unexpected user input. If you see one of these error messages you can email the developer at john@linstrum.net with details of how the error occured and the developer will try to fix the issue.

Program Hangs and Crashes

In theory, an app should never hang or crash no matter what the user does. Even if you think what you did was clearly a mistake, user mistakes should not crash an app. Unfortunately, the Visual RPN Calculator is not perfect and unexpected crashes and hangs can happen. If you come up with any condition that hangs or crashes the program, the developer would like to hear about it (john@linstrum.net). In particular, if you can give clear instructions on how to reproduce the error it would be greatly appreciated.