$THETAR

Gives Instructions for Transforming Final Thetas.

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 $THETAR  Fortran statements

;# EXAMPLE
 $THETAR
 THETAR=EXP(THETA)
;# or
 $THETAR
  THETAR(1:NTHETA)=EXP(THETA(1:NTHETA))
  THETAPR(1:NTHP)=EXP(THETAP(1:NTHP))

DISCUSSION

The purpose of $THETAR is to transform the final theta values for the NONMEM report and additional output files. The record name may also be coded as $THR.

In the above sample code, it is assumed that $THETAI was used to transform thetas from the natural domain to the log domain for estima- tion within NONMEM, such as when performing linear MU referencing. $THETAR causes them to be output in the natural domain as well.

This affects the following data in the output report:

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NPARAMETR
FINAL PARAMETER ESTIMATE for THETA.
FIRST ORDER STANDARD ERROR OF ESTIMATE
 THETA - VECTOR OF FIXED EFFECTS PARAMETERS
FIRST ORDER COVARIANCE MATRIX OF ESTIMATE
 THETA - VECTOR OF FIXED EFFECTS PARAMETERS

Contents of additional output files such as .coi and .cov and .cor are also affected.

The assignment statements may be any Fortran 95 statements. They are copied unchanged to subroutine SUBROUTINE THETARSUB in FSUBS (also found in thetair.f90).

They may include array assigment statements specifying the whole arrays or sections of arrays.

Arguments of the subroutine are as follows.

THETA Final estimates of theta. Input.
THETAP Final estimates of thetas specified on $THETAP records (or, if the informative names are not used, thetas corresponding to pri- ors, if any). Input.
THETAR New values of THETA. Output
THETAPR New values of THETA's for priors. Output.

Other reserved variables that may be used are as follows:

NTHETA Number of thetas to be estimated.
NTHP Number of theta priors.
NPROB IPROB These can be tested in IF statements so that values may be assigned diffently for different problems.

If the range is not specified, NONMEM to supply the range (which is by default NTHETA+NTHP).

$THR may be used with $THI, but not necessarily.

Another example is rescaling thetas. E.g., suppose that

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$THETAI
THETA=THETAI/10.

was used to rescale thetas on input.

Then

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$THETAR
THETAR=THETA*10.

can be used to report them in the original domain.

REFERENCES

Guide Introduction_7