![](png5YHk1fFv4p.png) | Sam, I think you should have gotten the error: INITIAL ESTIMATE OF OMEGA HAS A NONZERO BLOCK WHICH IS NUMERICALLY NOT POSITIVE DEFINITE which is the case. (you can check this in Excel, using the MDETERM function, the determinant is -2945). When you get this message, try reducing the off-diagonal elements, I think you'll find that $OMEGA BLOCK(4) 9 5 9 0 5 9 0 0 5 9 will work Mark Mark Sale MD
Next Level Solutions, LLC
www.NextLevelSolns.com
919-846-9185
-------- Original Message --------
From: Sam Liao <[EMAIL PROTECTED]>
Date: Fri, October 12, 2007 10:43 am
To: nmusers <nmusers@globomaxnm.com>
Dear NONMEM users:
Can someone please help me to solve this problem with a band matrix?
$OMEGA BLOCK(4)
0.09 ;BSV_V1C
0.07 0.09 ;BSV_CLC
0 0.07 0.09 ;BSV_CLN
0 0 0.07 0.09 ;BSV_V1N
Why this one above is getting an error in NONMEM?
$OMEGA BLOCK(4)
0.09 ;BSV_V1C
0.07 0.09 ;BSV_CLC
0 0 0.09 ;BSV_CLN
0 0 0.07 0.09 ;BSV_V1N
This one above is fine, but I need to run a simulation in which there
are some correlation between CLC and CLN.
There were some very helpful discussion on band matrix few years ago.
But I still couldn't figure out why this band matrix not permissible.
Sam Liao
<http://www.cognigencorp.com/nonmem/nm/96mar232001.html>
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