int | Bound | "B" When using pre-defined functions user parameter settings are used instead of default one |

int | Chi2 | "X" For fitting THnsparse use chi2 method (default is likelihood) |

int | Errors | "E" Performs a better error evaluation, calling HESSE and MINOS |

int | Gradient | "G" Option to compute derivatives analytically |

int | Integral | "I" Use function integral instead of function in center of bin |

int | Like | "L" Use Log Likelihood. Default is chisquare method except fitting THnsparse |

int | Minuit | "F" If fitting a polN, switch to minuit fitter |

int | More | "M" Improve fit results. |

int | NoErrX | "EX0" or "T" When fitting a TGraphErrors do not consider error in coordinates |

int | Nochisq | "C" In case of linear fitting, don't calculate the chisquare |

int | Nograph | "0" If set, do not display the function graph |

int | Nostore | "N" If set, do not store the function graph |

int | Plus | "+" Add new function (default is replace) |

int | Quiet | "Q" Quiet mode. No print |

int | Range | "R" Use the range stored in function |

int | Robust | "ROB" or "H": For a TGraph use robust fitting |

int | StoreResult | "S": Stores the result in a TFitResult structure |

int | User | "U" Use a User specified fitting algorithm (via SetFCN) |

int | Verbose | "V" Verbose mode. Print results after each iteration |

int | W1 | "W" Set all the weights to 1. Ignore error bars |

double | hRobust | value of h parameter used in robust fitting |