MINFIT DT mSR Fitting Programme:
Quick Reference

Dr Ivan D Reid, mSR Facility PSI

Chapter 1
Where to get this information

• MINUIT: A L^AT_EX version of the CERN MINUIT documentation.
• MINFIT: A description of the MINFIT programme, including commands which have been added to the basic MINUIT commands.
• MINFIT_HELP: This file, originally based on the VMS HELP file used by MINFIT. It is a quick reference describing all MINUIT and MINFIT commands, complete with a table of contents useful as a ``cheat sheet''.
• FCN: A brief mathematical treatment of c² fitting as it pertains to mSR data. Mainly useful for those contemplating writing additional fitting subroutines.

Chapter 2
MINFIT Flowcharts

Picture Omitted

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Chapter 3
OPTIONS

MINFIT option:

ASYMM

DELTAT

DELTAT COMMANDS

DELTAT accepts commands in the following format:

<command > <arg1 > [arg2] etc. <command >       ¯ is one of the commands listed below,
<argi >  are required arguments, if any.
[argi]   are optional arguments, if any.

The arguments (if any) are separated from each other and from the command by one or more blanks or a comma. Commands may be given in upper or lower case, and may be abbreviated, usually to three characters. The shortest recognized abbreviations are indicated by the capitalized part of the commands listed below. Parameter numbers may be replaced by their full names (without trailing blanks, case-insensitive); see the full documentation for restrictions.

!

[DELTAT command] ! [comment string] MINFIT command

Anything in a command to the right of an exclamation mark (!), including the exclamation mark, will be ignored. In particular, a line starting with an exclamation mark will be totally ignored. This allows comments to be entered in command-files for batch runs. The COMMENT command is used for inserting comments in the output.

?

? MINFIT command

This command is an abbreviation for HELP.

@

@[filename] MINFIT command

The @-command is used to read in further commands from an indirect command file given in the command. Default extension is `.DAT'. The command file may include further indirect command file calls, but the files are not ``stacked'' - command eventually returns directly to SYS$INPUT.

Indirect files are terminated when the end is reached, or when a call to a further indirect file cannot be satisfied (e.g. the command ``@''will cause termination).

CALlfcn

CALlfcn <iflag > MINUIT command

Instructs Minuit to call the current ``fcn'' subroutine with the value of IFLAG= <iflag >. This command is not normally required by a MINFIT user; in any event, a call with <iflag >=3 is to be avoided. A call with <iflag > greater than five leads MINUIT to ``forget'' the result of the fit to date.

CLEar

CLEar MINUIT command

Resets all parameter names and values to undefined. Not normally required by a MINFIT user.

COMment

COMment <comment string > MINFIT command

This allows comments, similar to the !-command, the difference being that COMMENT echoes the commentline to the terminal or log-file. Thus ! comments the input, COMMENT comments the output. If a COMMENT command contains an exclamation mark, the command will be truncated before being echoed!

CONtour

CONtour <par1 > <par2 > [devs] [ngrid] MINUIT command

Traces contour lines of the user function with respect to the two external parameters <par1 > and <par2 >. Other variable parameters of the function, if any, will have their values fixed at the current values during the contour tracing. The optional parameter [devs] (default 2.0) gives the number of standard deviations in each parameter which should lie entirely within the plotting area. Optional parameter [ngrid] (default value 25) determines the plot resolution.

This procedure gives a static picture of FCN as function of the two parameters specified by the user. All the other variable parameters (if any) are temporarily fixed at their current values. Contour zero is defined as the current best function value F_min, and then the i-th contour is defined as where FCN has the value F_min+ i² *UP. The method, although not very efficient or precise, is very robust, and capable of revealing unexpected multiple valleys.

FIX

FIX <parno > MINUIT command

Causes parameter <parno > to be removed from the list of variable parameters, and its value will remain constant (at the current value) during subsequent minimizations, etc., until another command changes its value or its status (e.g. RELEASE or RESTORE). A FIXed parameter is identified in a .PAR file by a negative value for the error estimate (as opposed to a constant parameter, which has 0.0 for the error estimate).

HELp

HELp [SET] [SHOw]

Causes MINFIT to list the available commands. The list of SET and SHOw commands must be requested separately. This VMS help file may also be accessed by using the DCL command

$ HELP/LIBRARY=MINFIT_HELP:MINFIT_HELP 

HESse

HESse [maxcalls] MINUIT command

Instructs Minuit to calculate, by finite differences, the Hessian or error matrix. That is, it calculates the full matrix of second derivatives of the function with respect to the currently variable parameters, and inverts it, printing out the resulting error matrix. The optional argument [maxcalls] specifies the (approximate) maximum number of function calls after which the calculation will be stopped.

IMProve

IMProve [maxcalls] MINUIT command

If a previous minimization has converged, and the current values of the parameters therefore correspond to a local minimum of the function, this command requests a search for additional distinct local minima. The optional argument [maxcalls] specifies the (approximate) maximum number of function calls after which the calculation will be stopped.

LOOsen

LOOsen [factor] MINFIT command

Expands error estimate on all parameters by [factor]. Default value of [factor] is 5.0. If the new error would overlap a limit on a bounded parameter, the error is reduced to avoid the overlap.

MIGrad

MIGrad [maxcalls] [tolerance] MINUIT command

Causes minimization of the function by the method of Migrad, the most efficient and complete single method, recommended for general functions (see also MINImize). The minimization produces as a by-product the error matrix of the parameters, which is usually reliable unless warning messages are produced. The optional argument [maxcalls] specifies the (approximate) maximum number of function calls after which the calculation will be stopped even if it has not yet converged. The optional argument [tolerance] specifies required tolerance on the function value at the minimum. The default tolerance is 0.1, and the minimization will stop when the estimated vertical distance to the minimum (EDM) is less than 0.001*[tolerance]*UP (see SET ERR).

MINImize

MINImize [maxcalls] [tolerance] MINUIT command

Causes minimization of the function by the method of Migrad, as does the MIGrad command, but switches to the SIMplex method if Migrad fails to converge. Arguments are as for MIGrad. Note that command requires four characters to be unambiguous with MINOS.

MINOs

MINOs [maxcalls] [parno] [parno] ... MINUIT command

Causes a Minos error analysis to be performed on the parameters whose numbers [parno] are specified. If none are specified, Minos errors are calculated for all variable parameters. Minos errors may be expensive to calculate, but are very reliable since they take account of non-linearities in the problem as well as parameter correlations, and are in general asymmetric. The optional argument [maxcalls] specifies the (approximate) maximum number of function calls per parameter requested, after which the calculation will be stopped for that parameter. In MINFIT, a default value of 1000 is taken for [maxcalls] if the first position is left blank. When parameter numbers are explicitly given, a maximum of six may be entered for each MINOS call.

MNContour

MNContour <par1 > <par2 > [ngrid] MINUIT command

This command was omitted in the original documentation. It seems similar to the CONTOUR command, but from the source it appears that the only optional parameter is [ngrid], the number of points on the contour (default 20).

The contour calculated by MNContour is dynamic, and represents the contour F_min +UP with respect to all the other NPAR-2 parameters (if any). In statistical terms, this means that MNContour takes account of the correlations between the two parameters being plotted, and all the other variable parameters. (If this feature is not wanted, then the other parameters must be FIXed before calling MNContour.) MNContour provides the actual coordinates of the points around the contour, suitable for plotting with a graphics routine or by hand. As a by-product, MNContour provides the MINOS errors of the two parameters in question, since these are just the extreme points of the contour (Use SHOw MINos to see them).

RELease

RELease <parno > MINUIT command

If <parno > is the number of a previously variable parameter which has been fixed by a command FIX <parno >, then that parameter will return to variable status. Otherwise a warning message is printed and the command is ignored. Note that this command operates only on parameters which were at one time variable and have been FIXed. It cannot make constant parameters variable; that must be done by redefining the parameter with a PARAMETER command.

REStore

REStore [code] MINUIT command

If no [code] is specified, this command restores all previously FIXed parameters to variable status. If [code]=1, then only the last parameter FIXed is restored to variable status.

SAVe

SAVe MINUIT command

Causes the current parameter values to be saved in a file which may be edited into a .CON or .PAR file. If the covariance matrix exists, it is also output in such a format. The unit number is by default 7, and the user is prompted for the file name (default FOR007.DAT). This is a pure MINUIT command; in general PARFILE is to be preferred when creating .PAR files.

SCAn

SCAn [parno] [numpts] [from] [to] MINUIT command

Scans the value of the user function by varying parameter number [parno], leaving all other parameters fixed at the current value. If [parno] is not specified, all variable parameters are scanned in sequence. The number of points [numpts] in the scan is 40 by default, and cannot exceed 100. The range of the scan is by default 2 standard deviations on each side of the current best value, but can be specified as from [from] to [to]. After each scan, if a new minimum is found, the best parameter values are retained as start values for future scans or minimizations. The curve resulting from each scan is plotted on the output unit in order to show the approximate behaviour of the function. This command is not intended for minimization, but is sometimes useful finding a reasonable starting point.

SEEk

SEEk [maxcalls] [devs] MINUIT command

Causes a Monte Carlo minimization of the function, by choosing random values of the variable parameters, chosen uniformly over a hypercube centered at the current best value. The region size is by default 3 standard deviations on each side, but can be changed by specifying the value of [devs].

SET

SET

Allows many options to be set, affecting MINUIT's strategy, performance, print-out level, etc.

SET BATch  

SET BATch MINUIT command

Informs Minuit that it is running in batch mode. Not necessary in MINFIT.

SET EPSmachine  

SET EPSmachine <accuracy > MINUIT command

Informs Minuit that the relative floating point arithmetic precision is <accuracy >. Minuit determines the nominal precision itself, but the SET EPS command can be used to override Minuit's own determination, when the user knows that the FCN function value is not calculated to the nominal machine accuracy. Typical values of <accuracy > are between 1.0E-5 and 1.0E-14. This should not be necessary in MINFIT.

SET ERRordef  

SET ERRordef <up > MINUIT command

Sets the value of UP (default value=1.0), defining parameter errors. Minuit defines parameter errors as the change in parameter value required to change the function value by UP. Normally, for chi-squared fits UP=1.0, and for negative log likelihood, UP=0.5. MINFIT users should normally leave this at 1.0.

SET GRAdient  

SET GRAdient [force] MINUIT command

Informs Minuit that the user function is prepared to calculate its own first derivatives and return their values in the array GRAD when IFLAG=2. If [force] is not specified, Minuit will calculate the FCN derivatives by finite differences at the current point and compare with the user's calculation at that point, accepting the user's values only if they agree. If [force]=1, Minuit does not do its own derivative calculation, and uses the derivatives calculated in FCN. This is more a debugging command, and is not normally needed as MINFIT forces MINUIT to accept gradients whenever they are calculable (all functions, at present).

SET INTeractive  

SET INTeractive MINUIT command

Informs Minuit that it is running interactively. Not necessary in MINFIT.

SET LIMits  

SET LIMits [parno] [lolim] [uplim] MINUIT command

Allows the user to change the limits on one or all parameters. If no arguments are specified, all limits are removed from all parameters. If [parno] alone is specified, limits are removed from parameter [parno]. If all arguments are specified, then parameter [parno] will be bounded between [lolim] and [uplim]. Limits can be specified in either order, Minuit will take the smaller as [lolim] and the larger as [uplim]. However, if [lolim] is equal to [uplim], an error condition results. See also SET PARAMETER and CHANGE.

SET LINesperpage  

SET LINesperpage MINUIT command

Sets the number of lines that Minuit thinks will fit on one page of output. The default value is 24 for interactive mode and 56 for batch.

SET NOGradient  

SET NOGradient MINUIT command

The inverse of SET GRAdient, instructs Minuit not to use the first derivatives calculated by the user in FCN.

SET NOWarnings  

SET NOWarnings MINUIT command

Supresses Minuit warning messages. SET WARnings is the default.

SET OUTputfile  

SET OUTputfile <unitno > MINUIT command

Instructs Minuit to write further output to unit <unitno > (i.e. the VMS file FOR <unitno >.DAT). This may be useful in some cases where the progress of a fit is to be recorded, but in general the LIST command is more help (being a temporary SET OUT command). To return to terminal output use SET OUT 6 (SET OUT 5 also works).

SET PAGethrow  

SET PAGethrow <integer > MINUIT command

Sets the carriage control character for ``new page'' to <integer >. Thus the value 1 produces a new page, and 0 produces a blank line, on some output devices (see TOPofpage command).

SET PARameter  

SET PARameter <parno > <value > MINUIT command

Sets the value of parameter <parno > to <value >. The parameter in question may be variable, fixed, or constant, but must be defined. Note that it is not possible to set a bounded parameter outside its bounds (see also CHANGE).

SET PRIntout   SET PRIntout <level > MINUIT command

Sets the print level, determining how much output Minuit will produce. The allowed values and their meanings are displayed after a SHOwPRInt command, and are currently <level >=:

1. no output except from SHOW commands (MINFIT default)
2. minimum output (no starting values or intermediate results)
3. normal output
4. additional output giving intermediate results
5. maximum output, showing progress of minimizations

Note: See also SET WARnings command.

SET PLOtlevel  

SET PLOtlevel <level > MINFIT command

Sets the plot level, determining the form of the graph produced by the PLOT and HISTPLOT commands. The allowable levels are

1. plots specified/default histogram (default)
2. plots all fitted histograms
3. plots single histogram with parameter list
4. plots all fitted histograms with parameter list

SET RANdomgenerator  

SET RANdomgenerator <seed > MINUIT command

Sets the seed of the random number generator used in SEEK. This can be any integer between 10,000 and 900,000,000; for example one which was output from a SHOw RANdom command of a previous run.

SET STRategy  

SET STRategy <level > MINUIT command

Sets the strategy to be used in calculating first and second derivatives and in certain minimization methods. In general, low values of <level > mean fewer function calls and high values mean more reliable minimization. Currently allowed values are 0, 1 (default), and 2.

SET WARnings  

SET WARnings MINUIT command

Instructs Minuit to output warning messages when suspicious conditions arise which may indicate unreliable results. This is the default.

SET WIDthpage  

SET WIDthpage MINUIT command

Informs Minuit of the output page width. Default values are 80 for interactive jobs and 120 for batch.

SHOw

SHOw

All SET commands have a corresponding SHOw command. In addition, the SHOw commands listed below have no corresponding SET command for obvious reasons. The full list of SHOw commands is printed in response to the command HELP SHOw. The LIST command is identical to the SHOW command, except that output is directed to a user-chosen file.

SHOw FUNCTION  

SHOw FUNction MINFIT command

Prints the function currently being used. If this is the COMPOUND function, a listing of the component signals is also given.

SHOw ALL  

SHOw ALL MINFIT command

Prints a fuller listing than SHOW RUN, including the chi-squared values and the current parameter values and relations if any. The output from SHOW FUNCTION is also given.

SHOw CORrelations  

SHOw CORrelations MINUIT command

Calculates and prints the parameter correlations from the error matrix.

SHOw COVariance  

SHOw COVariance MINUIT command

Prints the (external) covariance (error) matrix.

SHOw EIGenvalues  

SHOw EIGenvalues MINUIT command

Calculates and prints the eigenvalues of the covariance matrix.

SHOw FCNvalue  

SHOw FCNvalue MINUIT command

Prints the current value of FCN, i.e. the chi-squared sum, plus information on the fit status and number of calls. See also SHOW CHISQUARE.

SHOw MINoserrors  

SHOw MINoserrors MINUIT command

Prints the current minos errors.

SHOw CHIsquare  

SHOw CHIsquare MINFIT command

Shows the current chi-squared value, as well as the overall reduced chi-squared value and that for each histogram.

SHOw ESTimate  

SHOw ESTimate MINFIT command

Estimates and displays the normalisation and background for each histogram. Binning must be defined. The estimate is based on a least-squares fit of muon decay to the data, so it may be invalid when there are large, slowly varying features in the histograms. (See also NORMALIS).

SHOw RELation  

SHOw RELation MINFIT command

Shows the parameters currently defined through relations, plus the defining relation.

SHOw RUN  

SHOw RUN MINFIT command

Shows the current run number, title, and subtitles, as well as details of the histograms being fitted.

SHOw TIMe  

SHOw TIMe MINFIT command

Shows the elapsed CPU and real time since MINFIT was started.

SIMplex

SIMplex [maxcalls] [tolerance] MINUIT command

Performs a function minimization using the simplex method of Nelder and Mead. Minimization terminates either when the function has been called (approximately) [maxcalls] times, or when the estimated vertical distance to minimum (EDM) is less than [tolerance]. The default value of [tolerance] is 0.1*UP (see SET ERR).

STAndard

STAndard MINUIT command

Causes Minuit to execute the Fortran instruction CALL STAND where STAND is a subroutine supplied by the user. Does nothing in MINFIT.

TOPofpage

TOPofpage MINUIT command

Causes Minuit to write the character specified in a SET PAGethrow command (default = ``1'') to column 1 of the output file, which may or may not position your output medium to the top of a page depending on the device and system.

BINNING

BINning MINFIT command

Allows the user to enter the initial binning for a fitting session. Use REBIN for subsequent changes.

CHAnge

CHAnge [parameter] [value] [error] [lower bound] [upper bound] MINFIT command

Entered with no parameters, CHANGE enters an ``interactive'' mode, displaying all the parameters and prompting for a parameter to change. Once a parameter is selected the value, error, and limits can be entered. Any option left out will be left unchanged. Note that to retain the value as unchanged, you must enter <,error... >, as entering <0,error... > will set the value to zero. Note also that it's not possible to set the error to zero! The interactive mode is exited by entering a null value for the parameter to be changed. Entered with just a parameter number, CHANGE does not display the parameter list, but goes straight to the prompt for new values.

When entered with values as well as a parameter number, CHANGE will set the parameter and return directly to the command prompt. Note that you must enter a new value in this mode, although error and limits can retain their old values as defaults.

FUNction

FUNction [functname] MINFIT command

Allows the user to choose a new function to be fitted to the existing data file.

HISTPLOT

HIStplot [histogram] [mode] [start (raw) bin] [end (raw) bin] [packing] MINFIT command Plots the raw histogram data.

The start and end bins and the packing refer to the raw data, not the bins being fitted. All parameters default to the last value. Initial defaults are the lowest numbered histogram being fitted, mode 1, the whole histogram and binning by one. If the specified end bin is too large, it is truncated to the last bin.

The modes are similar to PLOT:

1. Raw data: The data are plotted.
2. Asymmetry: This is not valid for HISTPLOT.
3. Residuals: This is not valid for HISTPLOT.
4. Logarithmic: The data are plotted with a logarithmic count axis.

LOAD

LOAd [filename] MINFIT command

This command loads a .PAR file. If the name is not given, it will be prompted for. This is usually used at the start of a fit session.

NEWFile

NEWfile MINFIT command

Allows the user to read in a new data file. The default option is to retain the same histograms and binning, and the current fit parameters when fitting the new file. This facilitates analysing a series of runs with similar properties.

NORmalis

NORmalis [histograms] MINFIT command

Instructs DELTAT to insert its estimate of the normalisation N₀ and background B for each histogram (see SHOW ESTIMATE into the appropriate parameters. Binning and parameters must be defined. Default behaviour is to set N₀ and B for all histograms.

NEWPARS

NEWPars MINFIT command

Reads in new parameters from a .CON file, or prompts for new parameters in the case of the COMPOUND function. FUNCTION must be defined.

REBin

REBin MINFIT command

Allows the user to choose new binning for the current histogram(s). Current fit parameters are retained. Use BINNING for the initial choice.

PARfile

PARfile [filename] MINFIT command

Allows the user to write out the current fit settings into a .PAR parameter file, to be used as input into a later fit session. The default file-name is the current function, and the default extension is .PAR.

PLOT

PLOt [histogram] [mode] [start (fit) bin] [end (fit) bin] [packing] [binflag] MINFIT command Plots the data and the fitted function.

The start and end bins and the packing refer to the bins being fitted; [binflag], if non-zero, plots raw histogram bin numbers instead of time on the X-axis. All parameters default to the last value. Initial defaults are the lowest numbered histogram being fitted, mode 1, first and last fitted bin, binning by one and X=time. If the specified end bin is too large, it is truncated to the last fitted bin.

There are four plot modes:

1. Raw data: The data is plotted, along with the current fit.
2. Asymmetry: The current background and the muon decay are extracted from the data and the current normalisation used to get the asymmetry.
3. Residuals: The relative difference between the data and the current fit is plotted.
4. Logarithmic: This is a raw data plot with logarithmic count axis.

LISt

LISt <something >

This is an extension of the SHOW command, but the data is written to a file instead of displayed on the screen. The initial use of LIST will prompt for a file name; the default extension is .FIT.

WRITE

WRIte MINFIT command

This command allows the user to write the current parameters out to a MuFit-style .TXT file. It functions almost identically to the corresponding option in MuFit. MINOS errors are given where they exist; this has necessitated some slight extensions to the .TXT file format (see the full documentation for details).

QUIT

QUIT MINFIT command

Leaves DELTAT.

FUNCTIONS

There are several pre-defined full functions defined below, as well as the COMPOUND function which allows the user to build up his own customised function from discrete signals. Refer to the full documentation for the precise mathematical form of the functions.

STANDARD

This is a ``standard'' low-field function consisting of a Lorentzian relaxing muonium signal plus a non-relaxing muon signal.

LORENTZ

A single Lorentzian relaxing muon signal.

GAUSSIAN

A single Gaussian relaxing muon signal.

EXPROOT

A single muon signal with exponential-square-root relaxation.

POWER

A single muon signal with exponential-power relaxation.

ABRAGAM

A single muon signal with Abragam relaxation.

COMPOUND

This is the generic function built up from the signals described below.

Y(t) = b + N e-t/t é ë 1 + å i  am Gm(t) ù û

The signals include the TF functions, plus several longitudinal and zero-field signals. They can be referenced by the two-letter codes given to the signals in MuFit. In general, those with codes ending in `M' are muon signals where the oscillatory frequency is described by the applied field F, rather than directly in MHz. Refer to the full documentation for the precise mathematical forms of the signals.

MU  

The low-field muonium-plus-muon signal as in the STANDARD function.

EM  

A muon signal with Lorentzian relaxation.

GM  

A muon signal with Gaussian relaxation.

RM  

A muon signal with exponential-square-root relaxation

PM  

A muon signal with exponential-power relaxation.

AM  

A muon signal with Abragam relaxation.

E  

An oscillation (in MHz) with Lorentzian relaxation.

G  

An oscillation (in MHz) with Gaussian relaxation.

R  

An oscillation (in MHz) with exponential-square-root relaxation.

P  

An oscillation (in MHz) with exponential-power relaxation.

A  

An oscillation (in MHz) with Abragam relaxation.

KL  

A ``Lorentzian'' relaxing LF/ZF signal.

KG  

A Kubo-Toyabe Gaussian relaxing LF/ZF signal,

E0  

An oscillating LF/ZF signal with Lorentzian relaxation.

G0  

An oscillating LF/ZF signal with Gaussian relaxation.

Relations  

It is possible to define relations for various signal amplitudes ONLY. This allows you to specify, e.g. that all amplitudes in one histogram add up to some constant. Relations are specified as a string containing one to four coefficient/parameter pairs in the format

   Manual entry  

In manual entry, relations are entered at the value prompt. They are signified by entering the character 'R' as the first character in the entry. Only parameters of the type ``sig_hist'' will prompt for and accept relations; only amplitudes will successfully use them.

Example:
Value [...] or R<relation> for parameter AsyM\_S2H02: r0.2-p3

   PAR-files  

In a .PAR file, a relation is specified by a character 'R' in the first column of the line. The relation string starts in column 30 of the line. This allows the PARFILE command to write a .PAR file with the derived signal name and calculated value in the same columns as for a normal parameter. Fitting the ``worst-case'' relation into 50 characters is the main reason a relation is limited to four coefficients. Only signal amplitudes can be specified as relations.

Example:
...
GM
  7 Feld_S2     85.923455    , 0.86745568
  8 Sigm_S2    0.45148085    , 3.28593062E-02
R   AsyM_S2H01 5.29725650E-02+.170 -1.00P03                              
R   AsyM_S2H02 4.53263546E-02+.170 -1.00P04                              
...

FFT

The FFT option is in preparation.

HELP

This option leads the user into the VMS HELP file available for MINFIT.

MUMINUS

The MUMINUS option is not yet available.

QUIT

This option quits MINFIT.

Chapter 4
Batch Analysis

1. Include the commands directly in the batch command file, after the command $ RUN MINFIT. Don't start MINFIT commands with a dollar sign, however!

2. Put the commands into a separate file and define this to be MINFIT input with the command

   		$ define/user sys$input myfile.name

   before RUNning MINFIT.

The use of indirect command files (``@filename'') may be advantageous in batch runs.

Chapter 5
Logicals

Several VMS logicals are used to help locate the data files, determine the default file-name convention, and to locate the help library. These are most conveniently defined in your LOGIN.COM file to avoid having to type them in each time you want to run MINFIT.

MINFIT_HELP

MINFIT_HELP

This logical should be set to the directory containing the help library MINFIT_HELP.HLB. e.g. on the PSI cluster:

$ DEFINE MINFIT_HELP DISK_244_DAT0:[REID.MINFIT]

MINFIT_DATA

MINFIT_DATA

This logical should be set to the directory containing the data files to be analysed. The search strategy is first to look in the current directory, and then if the data file is not found there, it will be sought in the directory indicated by MINFIT_DATA.

Note: You MUST have the NETMBX privilege to access files on a different node, even though they are accessible to DCL commands. Ask the System Manager to grant you this privilege.

Examples:
$ DEFINE MINFIT_DATA USR_SCROOT:[myaccount]
$ DEFINE MINFIT_DATA PSM020::DUB0:[MUSR.EXP.TD_MUSR.DLOG]

MINFIT_NAME

MINFIT_NAME

This logical should contain a pattern which MINFIT uses to determine the data file's name from the run number. It should be of the form <string1 >NNNN <string2 >, where the Ns are replaced by MINFIT with the zero-padded run number. There should be as many Ns as there are digits in the file name (minimum 4). The file extension should be explicitly given in <string2 > as no default is assumed.

Examples:
$ DEFINE MINFIT_NAME RNNNN.TX
$ DEFINE MINFIT_NAME deltat_imp_NNNN.dat