NONMEM Users Network Archive

Hosted by Cognigen

Deat Jun,the covariance?

From: yhb5442387
Date: Mon, 14 Dec 2009 23:10:55 +0800 (CST)

Dear Jun:
Sorry for making you in the reading trouble:
Here is my question:
Is there any special specification on the employ of covariance:
The papers which I have read most always take the covariance excluded,such as W21,w31 w32.If the Decrease of OFV between the model of the covriance included and the one not is significantly meaningful,what choice should I do? I really do not understand the correlation of Cl and V,if the convariance between the two parameters does exist.Dose it truly exist in physiologically or just mathematically?
Dear Hongpo,

I am not sure I understand your question. Can you rephrase?

Jun Shen
Millipore Corporation

2009/12/13 yhb5442387 <yhb5442387

Dear professor:

THE off diagnoal:

Sometimes we make the OMEGA syntax as follows:$omega 0.1 0.1,but $omega blokc (2) 0.1 0.01 0.1 at another occasion.As we know,the only difference is whether the off diagonal estimate be used.So is there any specila condition about the existence of the W21,or some another W square like that?

Thank you !!!

Received on Mon Dec 14 2009 - 10:10:55 EST

The NONMEM Users Network is maintained by ICON plc. Requests to subscribe to the network should be sent to:

Once subscribed, you may contribute to the discussion by emailing: