lat lon precision and/or truncation

[pmpowers-usgs]

When entering specific decimal lat lon coordinates, the widget truncates the entered values on clicking 'search'. In the earthquake-hazard-tool, the value is truncated to a single decimal place; in earthquake-usdesign the value is truncated to 0 decimal places.

One could argue that this does not instill user confidence that the values they entered will be used for a calculation and that if a user enters lat=32.045 then the field should preserve that value.

Of course, if a user enters something unreasonably precise 32.0450123471, truncating to 4 or 5 decimal places is probably ok.

[jmfee-usgs]

Can you clarify how the decimal coordinates are being entered? This is using the location view rather than the input boxes?

This suggests we round to 3 decimals in earthquake-hazard-tool, unless they were entered manually:
https://github.com/usgs/earthquake-hazard-tool/blob/master/src/htdocs/js/input/Location.js#L178

[pmpowers-usgs]

Scratch the original comment. The issue is the precision comparison between the two fields on the 'x,y' option of the location view. If I enter 40.0 and -117.25, my location is changed to 40.0 and -117.3, and that is where the pin drops. Moreover, the first click on search will shorten 40.0 to 40, at which point a second click will set my longitude to -117, because my lat precision has decreased.

I would set a hard limit of 5 decimal places (meter-scale precision more or less) regardless, and just leave user entered values alone below that precision, other than checking for them being valid lat-lon values.

[jmfee-usgs]

I think it's attempting to keep similar precision between latitude and longitude values. For example, if I enter 40.00 and -117.25 the values are preserved without rounding; even though the trailing zeros are removed from the latitude...