From Michael_Looby@sandwich.pfizer.com Fri Oct 4 03:14:19 1996
Subject: strange error
I have encountered a strange error while checking the nmtran pred code listed below. When I run this code (without the estimation step) on a VMS Alpha, I get the following NONMEM error:
PROGRAM TERMINATED BY OBJ, ERROR IN ELS
WITH INDIVIDUAL 1 (IN INDIVIDUAL RECORD ORDERING)
VAR-COV OF DATA FROM INDIVIDUAL RECORD ESTIMATED TO BE SINGULAR
MESSAGE ISSUED UPON EVALUATION OF OBJ. FUNCTION
*** Line 1 *** which calculates A3 from the negative sum of A1 and A2 seems to be causing the problem. When I replace LINE 1 with LINE 2 (which gives the result of the calculation that should be performed in LINE 1) the code runs without error
Can anyone explain this?
Best wishes
Mick Looby
-------------------------------------------------
$PROBLEM TEST
$INPUT ID TIME CON=DV ND
$DATA TEST.DAT
$PRED
A1 = THETA(1)
A2 = THETA(2)
LA1 = THETA(3)
LA2 = THETA(4)
LA3 = THETA(5)
; *** LINE 1 ***
A3 = -(A1 + A2)
; *** LINE 2 ***
;A3 = -9.95
TAU = 8
TI = TIME - (ND - 1) * TAU
EX1 = EXP(-LA1 * TI)
EX2 = EXP(-LA2 * TI)
EX3 = EXP(-LA3 * TI)
EX11 = 1 - EXP(-LA1 * TAU * ND)
EX22 = 1 - EXP(-LA2 * TAU * ND)
EX33 = 1 - EXP(-LA3 * TAU * ND)
EX111 = 1 - EXP(-LA1 * TAU)
EX222 = 1 - EXP(-LA2 * TAU)
EX333 = 1 - EXP(-LA3 * TAU)
AA1 = A1 * EX1 * EX11/EX111
AA2 = A2 * EX2 * EX22/EX222
AA3 = A3 * EX3 * EX33/EX333
F = AA1 + AA2 + AA3
Y = F * EXP(ERR(1))
$THETA
6.75
3.2
10.7
0.136
9.17
$OMEGA .2
;$ESTIM
------------------------------------
Data to be simulated:
1 0 0 1
1 1 0 1
1 4 0 1
1 8 0 2
1 9 0 2