+--------------------------------------------------------------------+
 |                                                                    |
 |                            YLO EXAMPLE                             |
 |                                                                    |
 +--------------------------------------------------------------------+

 In  this  example,  blood  concentrations below a known quantification
 limit (BQL) have been  eliminated  from  the  analysis.   A  one-sided
 interval  with  lower  boundary  equal  to the quantification limit is
 defined.  The conditional likelihood for  an  observation  is  "condi-
 tioned"  on values of the population parameters and also on the condi-
 tion that the observation is inside the one-sided interval.
 (See pr_y, YLO YUP)
 (See YLO YUP Probability: PR_Y).

 Here is an NM-TRAN control stream.

 $PROB YLO example
 $INPUT ID TIME DV AMT EVID MDV
 $DATA ylow.dat IGNORE=C
 $SUBROUTINES ADVAN=1 TRANS=2
 $PK
 CL=THETA(1)*EXP(ETA(1))
 V=THETA(2)*EXP(ETA(2))
 K=CL/V
 S1=V

 $ERROR
 ; Limit of Quantification (LOQ) is 1
 ; DV's below LOQ are given MDV=1 in dataset
 ; PR_Y (PRB) is probability that DV is > LOQ
 ; PR_Y (PRB) is provided even if MDV is 1

     YLO=1
     PRB=PR_Y
     Y = F+ERR(1)

 $THETA
 (0,0.693); CL
 (0,24); V
 $OMEGA
 0.09
 0.09
 $SIGMA
  .5
 $ESTIMATION
       MAXEVAL=9999
       NSIG=4
       METHOD=COND INTERACTION LAPLACIAN
       PRINT=5
 $TABLE ID TIME AMT MDV EVID PRB
   NOPRINT
   ONEHEADER
   FILE=ylo.tab

 Here is a segment of the dataset for a subject with last DV < LOQ

       ID    TIME     DV      AMT   EVID     MDV
        .      .       .       .      .       .
        .      .       .       .      .       .
        .      .       .       .      .       .
        2       0       0     100     1       1
        2   0.333    2.47       0     0       0
        2       2    3.26       0     0       0
        2       6    2.32       0     0       0
        2  15.917    2.46       0     0       0
        2      24       0     100     1       1
        2      48       0     100     1       1
        2      72       0     100     1       1
        2  95.917    4.04       0     0       0
        2      96       0     100     1       1
        2   96.08    8.85       0     0       0
        2     120    3.16       0     0       0
 C Last observation record (below) has DV < LOQ (LOQ = 1) and MDV = 1
 C This observation does not contribute to the -2LL estimate. However,
 C probability that DV is > LOQ can be tabled using PRB=PR_Y.
        2     168   0.163       0     0       1

 REFERENCES: None.


  
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