Ln(DV)

From: "Luciane Velasque" Subject: [NMusers] Ln(DV) Date: Thu, 13 Mar 2003 10:45:30 -0300 I am trying to work with Ln(DV) and the ERROR record is : $ERROR IPRED=F IF(IPRED.EQ.0) IPRED=EXP(-9) Y=LOG(IPRED)+ERR(1) ESTIMATION POSTHOC The NONMEM returns me 0MINIMIZATION SUCCESSFUL NO. OF FUNCTION EVALUATIONS USED: 4621 NO. OF SIG. DIGITS IN FINAL EST.: 5.1 0R MATRIX ALGORITHMICALLY NON-POSITIVE-SEMIDEFINITE BUT NONSINGULAR 0COVARIANCE STEP ABORTED 0PRED EXIT CODE = 1 0INDIVIDUAL NO. 1 ID= .10000000E+01 (WITHIN-INDIVIDUAL) DATA REC NO. 1 THETA= 3.32E-02 2.22E-03 2.51E-05 9.00E-06 1.18E-01 OCCURS DURING SEARCH FOR ETA AT A NONZERO VALUE OF ETA ERROR IN TRANS4 ROUTINE: Q IS NEGATIVE 0PROGRAM TERMINATED BY FNLETA MESSAGE ISSUED FROM TABLE OR SCATTERPLOT STEP What shall I do ?