2 replies to this topic

[kengwah96]

Dear all,

 

I noticed in the Pirana 23.1.2 release updates, there is an update to the formula used for the calculation of RSE for sqrt(exp(OM^2) - 1) transformed Omega and Sigma.

 

Previous formula: RSE% = %RSE_{untransformed}/2

 

New formula: RSE% = exp(ParameterValue)/ (2*(exp(ParameterValue) – 1)) *ParameterValue*(%RSE_{untransformed}).

 

However, I am unable to find additional background information on the switch. Would appreciate it if someone could shed some light on this.

 

Many thanks.

Keng Wah

Edited by kengwah96, 16 August 2023 - 04:33 AM.

[kniefort]

Hi Keng,

 

The new formula is simply the correct one for calculating RSE% for that particular transform.  The previous formula was an approximation that lost accuracy as omega values increased. 

 

The background would come from error propagation theory in statistics, i.e., see https://en.wikipedia..._of_uncertainty.

 

If you have further questions, please post and we can involve some of our mathematicians in the conversation!

[kengwah96]

Many thanks for the explanation! 

Hi Keng,

 

The new formula is simply the correct one for calculating RSE% for that particular transform.  The previous formula was an approximation that lost accuracy as omega values increased. 

 

The background would come from error propagation theory in statistics, i.e., see https://en.wikipedia..._of_uncertainty.

 

If you have further questions, please post and we can involve some of our mathematicians in the conversation!