# TIP:  Where to find the square root of Omega (CV%)

**URL:** <https://forum.certara.com/t/tip-where-to-find-the-square-root-of-omega-cv/2202>\
**Category:** Modelling and Simulation\
**Created:** [July 15, 2010, 10:35pm UTC](https://forum.certara.com/t/tip-where-to-find-the-square-root-of-omega-cv/2202 "2010-07-15T22:35:20Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ana.henry](https://sea1.discourse-cdn.com/certara/user_avatar/forum.certara.com/ana.henry/32/2578_2.png) [@ana.henry](https://forum.certara.com/u/ana.henry)\
**Post date:** [July 15, 2010, 10:35pm UTC](https://forum.certara.com/t/tip-where-to-find-the-square-root-of-omega-cv/2202/1 "2010-07-15T22:35:20Z")

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Sometimes it is helpful to look at the square root of the Omega matrix in order to determine inter-subject variability as an approximate coefficient of variation (CV %). In Phoenix NLME the square root of the Omega Matrix is referred to as the Cholesky matrix and it is abbreviated ‘omega5chol #’. This matrix can be located in the Core Status text output.