Pirana 23.1.2 RSE for Omega & Sigma

[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

[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.org/wiki/Propagation_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!

@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.org/wiki/Propagation_of_uncertainty.

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