When you enter a user-defined equation, you can write a different model for different data sets. If no model is defined for certain data sets, the message "Equation not defined" will appear in the results for that data set, with no other results.

•"Bad initial values"

•"Interrupted"

•"Not converged"

•"Ambiguous"

•"Hit constraint"

•"Don't fit"

•"Too few points"

•"Perfect fit"

•"Impossible weights"

•"Equation not defined"