After much revamping, here is the logSpiral5 script, which supersedes version 4.

A help button was added with Michael's tremendous help.
The Help alert box text took several hours to type up and correct.

Script was returned to the .js file, from the .htm file.

The center point can have a zero or non-zero z value.
The spiral is in a plane parallel to the xy plane.
Perhaps the preferred view is Top View

An Inward_Outward checkbox was added.

Golden spiral is described.

Decay percentage is explained, and how to convert decay percentage to the logSpiral curve and parameter exponent "b".
The expansion value is the reciprocal of the decay percentage, for outward versus inward spiral curve.
The Help alert box helps to explain the confusion which can result.

Wikipedia provides a lot more information

- Brian