$MIX

Marks the beginning of the abbreviated code for the MIX routine.

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 $MIX
 abbreviated code

;# Example
 $MIX
 NSPOP=2
 P(1)=THETA(5)
 P(2)=1-THETA(5)

The $MIX record is used to describe the mixture probabilities of a mixture model. It is evaluated with individual records.

$MIX block may not include EXIT, CALL , DO WHILE / ENDDO statements, or COMRES, CALLFL options.

NSPOP: the number of sub-populations (mixture components). It must be defined during problem initialization (when ICALL=1 ).
P(m), m=1..., NSPOP, the probability of certain subject belonging to subpopulation m. Thus P(m)'s must sum to 1. P has alias MIXP in the $MIX block.

THETA.
MIX-defined variables.
ICALL.
Data items listed in DATA option of the $CONTR record, e.g.,
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$INPUT ... STDY ... $CONTR DATA=(STDY)
so that STDY can be used in $MIX. STDY(j) refers to the value of STDY on the j'th observation record of the individual record. TEMPLT may be used;
MIXNUM: global variable for subpopulation index. During ICALL=4 (simulation), MIXNUM is randomly selected. During ICALL=3 (estimation) and the PASS subroutine used, or when ICALL=5 or ICALL=6, MIXNUM equals to MIXEST.
MIXEST: global variable for the estimated index. when ICALL=3,5,6, and at ICALL=2 when COMACT \= 0, MIXEST is the the estimated index m of the subpopulation with highest P(m) for the individual. This can be seen as the subpopulation to which the individual is classified. In NM73+, when ICALL=4, MIXEST equals to MIXNUM. At other times the variable is not meaningful.
MIXP: global array of probabilities of the mixture components, as the internal storage of the P variable. MIXP may be encoded in one of the three ways below:
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MIXP(MIXNUM) MIXP ! index default to MIXNUM MIXP(m)
The third encoding requires that the index m not exceed the value of MMX in SIZES.
Some global Variables in addition to MIXNUM, MIXEST, and MIXP.
Reserved variable NEWIND, ETA, EPS, ERR, COM.

Variables defined in $MIX are not stored in module NMPRD4 for output thus may not be specified in $TABLE.

Follows $SUBROUTINES.