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| PRED |
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MEANING: PRED subroutine
CONTEXT: User-supplied routine; required with NONMEM
USAGE:
PRED (ICALL,NEWIND,THETA,DATREC,INDXS,F,G,H)
INTEGER ICALL,NEWIND,INDXS
DIMENSION THETA(*),DATREC(*),INDXS(*),G(LVR,*),H(LVR,*)
REAL DATREC
(If double precision is to be used):
DOUBLE PRECISION THETA,F,G,H
(If single precision is to be used):
REAL THETA,F,G,H
The value of LVR must be the same as that found in file SIZES
(See sizes).
DISCUSSION:
The PRED subroutine is called by NONMEM to obtain modeled values.
(PREDPP is a PRED subroutine that is distributed with NONMEM.)
Input argument:
ICALL
ICALL=0: PRED has been called for initialization purposes at the
beginning of the NONMEM run; one such call per run. DATREC con-
tains the first data record. THETA contains the initial esti-
mates. PRED need not compute F, G, or H.
ICALL=1: PRED has been called for initialization purposes at the
beginning of a NONMEM problem; one such call per problem. Other-
wise, identical to ICALL=0.
ICALL=2: For the data record contained in DATREC, PRED has been
called for the purpose of computing F, the value of the predic-
tion, and/or the values of other PRED-defined items, appropriate
for the record. PRED should compute F, and also G and H as
appropriate. THETA contains the values to be used to compute F.
With conditional estimation, to obtain ETA values, PRED should
call GETETA.
ICALL=3: PRED has been called for finalization purposes at the
end of a NONMEM problem; one such call per (sub)problem. DATEC
contains the first data record. THETA contains the final esti-
mates. Otherwise, identical to ICALL=0.
ICALL=4: For the data record contained in DATREC, PRED has been
called during the Simulation Step for the purpose of computing a
value of the dependent variable and, possibly, values of indepen-
dent variables, appropriate for the record. PRED should compute
F (the value of the dependent variable). THETA contains the ini-
tial estimates, which are the values to be used to compute F.
PRED should call SIMETA (and SIMEPS) to obtain simulated values
of ETA (and EPS).
ICALL=5: For the data record contained in DATREC, PRED has been
called for the purpose of computing the expectation of the PRED
item and possibly, the expectations of other PRED-defined items,
appropriate for the record. Such a call occurs when the marginal
data item (MRG_) is defined in the data set and has a non-zero
value for the data record in question. If the MRG_ data item on
the record has the value 1 or 2, the value returned by PRED in F
contributes to the expectation of the PRED item. Similarly, the
values returned in other PRED-defined items contribute to expec-
tations of these items. THETA contains the final estimates. The
expectations in question are over possible values of ETA, and to
obtain ETA values, PRED should call GETETA.
ICALL=6: PRED has been called for the purpose of computing the
raw data average of the DV data items and, possibly, the raw data
averages of PRED-defined items. Such a call occurs when the
raw-data data item (RAW_) is defined in the data set and has a
non-zero value for a template data record (See template). The
value of the DV data item in the data record contained in DATREC
will be included in the raw data average of the DV data items.
However, when the raw data average corresponding to the label DV
in a table or scatterplot is to be different from the raw data
average of the DV items themselves, PRED may recompute the value
of DV. PRED may return a value of 1 in F to omit the DV item in
the data record from the average.
NEWIND
NEWIND=0: First record of the data set. THETA value may differ
from value at last call with this record.
NEWIND=1: First record of the data set, THETA value does not
differ from value at last call with this record, and PRED is non-
recursive (see NMPRD8), or,
First record of a subsequent individual record.
NEWIND=2: Subsequent data record of an individual record.
THETA
The NONMEM THETA vector.
DATREC
The current data record.
INDXS
The values specified in the $INDEX record of the NM-TRAN control
stream.
Output argument:
F When ICALL=2, the prediction associated with the data record.
With odd-type data, the likelihood of the observation in the
record, but if there is no observation, F is ignored.
When ICALL=4, the value of the simulated observation associated
with the data record. Alternatively, F can be ignored, and the
DV item in the data record can be directly set to the value of
the simulated observation. With odd-type data, F is ignored;
PRED should directly set the DV item to the value of the simu-
lated observation.
G An array of derivatives of F with respect to etas. Values should
be set when ICALL=2.
G(i,1) is the partial derivative of F with respect to eta(i).
When the data are population, G(i,j+1) is the second partial
derivative of F with respect to eta(i), eta(j) (lower-triangular;
j=1,..., i).
Second derivatives are needed only when the Laplacian method is
used to estimate parameters.
H An array of partial derivatives of F with respect to epsilons.
When the data are population, values should be set when ICALL=2.
H(i,1) is the derivative of F with respect to eps(i).
H(i,j+1) is the partial derivative of H(i,1) with respect to
eta(j)
These mixed second derivatives are needed only when the INTERAC-
TION option is used to estimate parameters. (See $ESTIMATION).
Also see NONMEM read-only commons (of the form ROCMn), NONMEM-PRED
commons (of the form NMPRDn), and PREDPP read-only commons (of the
form PROCMn).
REFERENCES: Guide I Section C.2
REFERENCES: Guide IV Section III.B.8, IV
REFERENCES: Guide V Section 12.3
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