$SIGMAP, $SIGMAPD

Gives prior information for sigmas.

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 $SIGMAP  value1  [value2]  [value3] ...
 $SIGMAPD  value1  [value2]  [value3] ...

;# EXAMPLE
 ;# Prior to SIGMA (NEPPxNEPP=1x1 of them)
 $SIGMAP 0.05 FIX
 ;# Set degrees of freedom of SIGMA Prior (one value per SIGMA block)
 $SIGMAPD (1 FIX)

DISCUSSION

These are called the informative forms of the $SIGMA record, for use with the NWPRI utility.

$SIGMAP gives prior information for elements of the SIGMA matrix. $SIGMAPD gives degrees of freedom (also called the dispersion factor) for SIGMA priors.

The name of the record describes the kind of information it gives, rather than the structure of the information. E.g., in the example above, $SIGMAPD is implemented in FCON with a $THETA record because it is always a vector of values. These records may be located anywhere in the control stream. NM-TRAN inserts the corresponding records in the control stream in the correct order. When the informative forms are used, the options of $PRIOR NWPRI need not be specified. However, if options are listed in $PRIOR NWPRI, then these values are chosen over what is surmised from the informatively labeled theta/omega/sigma records.

(See NWPRI).

OPTIONS

The option FIXED should be used. Other appropriate options are BLOCK and VALUES.