Note

In data-driven mode, that is with CALL MINUIT, you should not call MNINIT, since Minuit takes care of all initialization. To change unit numbers, call MINTIO before calling MINUIT.

In order that control returns to the user program after CALL MINUIT, the last command in the corresponding Data Block should be [RETurn]RETURN. If the last command is EXIT or STOP, then Minuit will execute a Fortran STOP, and if the last command is END, Minuit will read a new Data Block from the current input unit.

10cmData to drive Minuit

In data-driven mode, either interactively or in batch, Minuit reads the following data provided by the user:

• Title: (a string of 50 characters or less) which can be chosen freely by the user, to help identify the job.
• Parameter definitions: for each parameter one record giving:

  The parameter number. This is the index in the array XVAL by which the user function FCN will access the value of the parameter.

  The parameter name. A string of ten characters to help the user in reading the Minuit output.

  The starting value of the parameter.

  The starting step size, or expected uncertainty in this parameter, if it is to be a variable parameter. Otherwise blank or zero if the value is to be constant.

  Optional

  The lower bound (limit) below which the parameter value must not vary.

  Optional

  The upper bound (limit) above which the parameter value must not vary.

  Normally the user should not specify limits on the parameters, that is both should be left blank. If one limit is specified, then BOTH must be specified. The properties of limits are explained elsewhere in this document.

  The format of the parameter definitions may be either fixed-field (each item in a field of width ten columns), or in free-field format. In the free-field format, items are separated by blanks or one comma, and the parameter name must be given between single quotes. The program assumes free-field format if it finds two single quotes in the line. Parameter names will be blank-padded or truncated to be ten characters long.

• A blank record: indicates the end of parameter definitions.
• If the user FCN reads input data from the same input stream as the Minuit data (the default stream is UNIT 5), then the FCN data should appear here.
• Minuit commands: these specify actions which should be performed by Minuit. Commands must not contain leading or embedded blanks, but may be truncated to three characters, and may be given in upper or lower case. Some commands have numerical arguments, and these may be given in free-field format, separated by blank(s) or one comma. The list of recognized commands is given and explained below. The command HELP causes Minuit to write to the output stream a list of currently recognized commands. The command HELP SHOw lists the available SET and SHOw commands.

Any or all of the above data read by Minuit can reside on one or more different files, and Minuit can be instructed to switch to reading a different file with the [SET INPut]SET INPUT command. Optionally, the title record may be preceeded by a record beginning with the characters [SET TITle]SET TITLE, and the parameter definitions may be preceeded by a record beginning with the characters [PARameters]PARAMETERS. It is in fact recommended always to include these optional records when preparing a data file, since the file can then be read at any time (not just at the beginning of a Minuit run) and will always be interpreted correctly by Minuit.

Example of a typical Minuit data set