FL: (Fault Logic) is true if mesage is error and program terminate, False if message is warning and result might not be accurate.
FN: (Fault Number) is a code for the error mesage.
FT: (Fault Text) is error text.
FF: (Fault File) is the first origin of fault createor, but during the computation will represent the function that raised error.
Details
db.Fault is the database of errors that might occure in all functions of the nlr package. Termination of the functions can be due to error or warning. If error happened no output is returned, if warning happened output returned but might not be reliable. Warning kight happen for example if number of iteration exceeded the maximum number of iteration. Then a sugestion will be displayed for remedy the problem. The returned variable is a "Fault" that display the mesage code, number, and file that error happened.
References
Riazoshams H, Midi H, and Ghilagaber G, 2018,. Robust Nonlinear Regression, with Application using R, Joh Wiley and Sons.