# Quick way to produce polygons to cover variable precision lat / lon points?

I'm using the Smithsonian Global Volcanism Database and have a .csv lat lon points from it. It seems they are using decimal precision on their lat lon to give a rough idea of the size of the area that a volcanic center covers. For example, the enormous Phlegrean Fields are given as 37.1, 12.7 while a single volcano like Vesuvius is given as 40.821, 14.426. At least I think that's what they're trying to do (and yeah, I realize that would be a bad way to do things).

Anyway, what I want to do is create polygons that cover the entire area specified by the imprecise locations for each volcano. I mostly use QGIS and related open source tools and I could probably script this in QGIS python pretty easily, is there an existing tool I can use to do this instead?

EDIT: Note that often the latitude precision does not match the longitude precision. For example, Kurab volcano is given as 11.88, 41.208 .

In your csv, create a new 'size' field that counts the number of decimals in the lat/long fields. Use that as a sort of key to buffer the points at variable distances (and hence, create your polygons of different sizes).

EDIT for less vagueness:

1. In Excel or similar, extract the number of decimal places into a new column (let's call it 'size' since you are inferring that the number of decimals is the inverse of the size of the volcano/area).

Volcano | Lat | Long | Size
Vesuvius | 40.821 | 14.426 | 3
Phlegrean |37.1 | 12.7 | 1

You now have a relative size indicator you can use to size your polygons.

1. I would then alter the values in the 'size' column to be the size you want to buffer the points (e.g. 1=10km, 2=5km, 3=1km)