Modify Hazard service response to process max-direction and truncate options

• truncate: strip values below first value less than 1e-4
• max-direction: apply scale factors (attached)

Max-direction_Scale_Factors_for_Web_Service_v190107.xlsx

changed milestone to %NSHM App Update

added Services label

added To Do label

changed the description

mentioned in issue #450 (closed)

mentioned in merge request !509 (merged)

added Needs Review label and removed To Do label

closed with merge request !509 (merged)

mentioned in commit 7082888b

removed Needs Review label

marked the checklist item truncate: strip values below first value less than 1e-4 as completed

marked the checklist item max-direction: apply scale factors (attached) as completed

Although the supplied scale factor for PGA supplied for this issue/enhancement is 1.0, it actually should be 1.2 for structural engineering applications. Also would need to be changed in nshmp-apps. Confirm with @amakdisi and/or @srezaeian

reopened

Unless users are clamoring for a "max-direction PGA", I'm not sure it makes sense to implement the 1.2 factor for PGA. As far as I know, PGA isn't being widely used for structural engineering applications - it's primarily used for geotechnical applications, where the geometric mean is maintained.

That being said, there was a BSSC meeting earlier this year where there was some discussion about engineers using PGA as a proxy for a "zero-period" spectral acceleration for certain structural applications, although I don't recall a consensus being reached on that issue... @nluco may be able to weigh in?