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marleymarl / geotimeline

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Reduce size of table #29

Closed heldersepu closed 4 years ago

heldersepu commented 4 years ago

Currently the table is displaying the lat and lon with 14 digits after the dot:

Screenshot from 2020-03-30 14-38-05

That is an overkill, we can reduce to just 6 without any problems

Screenshot from 2020-03-30 14-38-08

heldersepu commented 4 years ago

There is a good answer on SO that talks about this: https://gis.stackexchange.com/a/8674

The sixth decimal place is worth up to 0.11 m: you can use this for laying out structures in detail, for designing landscapes, building roads. It should be more than good enough for tracking movements of glaciers and rivers. This can be achieved by taking painstaking measures with GPS, such as differentially corrected GPS.

And is interesting to see:

The ninth decimal place is worth up to 110 microns: we are getting into the range of microscopy. For almost any conceivable application with earth positions, this is overkill and will be more precise than the accuracy of any surveying device.

When the time comes to save this data maybe we should consider just 8 decimal places? @marleymarl :eyes: :point_up:

marleymarl commented 4 years ago

I won't know about that until I do the time-geo proximity matching code which I have spec'ed but not written yet. We can revisit after that. If it's about saving space in the table for display though, we could just have function to prep the data for the table by mapping each object in the footprints array and reducing their lat/lon decimal places by X amount.

LOL looks like that's exactly what you did now that I reviewed the code. :)

heldersepu commented 4 years ago

LOL looks like that's exactly what you did now that I reviewed the code. :)

Yep: .toFixed(6) easy fix