[Xastir] Xastir on Mac . . . download, unzip, store maps

[Curt, WE7U]

On Thu, 6 Jan 2011, T Wegner wrote:

> Thanks . . . I've read so many FAQ's, Help files, and README's in the last 3 
> days, 90% of which are over my head, it's . . . well . . . .

> 1) Do you (others welcome too) have any insight as to what the main 
> difference (from an end user standpoint) would be between the osm and 
> shapefile map offerings.

> OSM XML files are the native format used by the OpenStreetMap API and also by 
> many OpenStreetMap applications.

> Shapefiles are a data exchange format created by ESRI which are one of the 
> most widely used geodata formats.

> 2) There are other types as well but from what I've read I believe maybe the 
> Shapefiles version is the way to go.  Why such a large difference in file 
> size?

OSM XML files are in XML format, ever looked at XML files?  They have a lot of pairs of tags in them, plus it appears the files they describe above are the complete database.

Xastir uses a much more compact format which is only some extracts from the main OSM database, but have just the vectors/points/labels that we need.

Then there's a third type of OSM maps:  The online maps.  In this case we download a complete raster image that we display in Xastir, or small raster tiles which we stitch together, depending on the Map Chooser selection.  Tiles are better/faster 'cuz we cache them locally and if you move slightly you only have to grab a few more tiles to complete the picture.

Xastir is quite happy with Shapefiles and this is the format I'd recommend for offline use.


> mv *.zip /usr/local/share/xastir/maps

Yes, as root usually, or use "sudo"

> unzip *.zip

Yep.


> 4) there is mention of 4 different files for each shapefile map, do you think 
> it wise for me to make a subdirectory for, say, "wisconsin" so the map 
> directory does not get all cluttered up? Do all 4 of these files show up in 
> the "map chooser" menu?

Only one of them shows up in the Map Chooser for a shapefile set.  Feel free to create subdirectories under the maps directory at will.  That's how I organize my maps.


> 5) Is there any way to preview maps . . . I'm overwhelmed at the offerings 
> available and don't know where to begin.

Not in Xastir.


> 6) what's the recommendation on the number of different questions a person 
> should ask in a single e-mail?

One.  hi hi

Shorter e-mails with just one or two questions seem to get read/answered by more people.  Longer ones often get skipped because people aren't wanting to dedicate minutes of their life to reading/understanding them right at that time.  Often responses get delayed because of that.

-- 
Curt, WE7U.                         <http://www.eskimo.com/~archer>
    APRS:  Where it's at!                    <http://www.xastir.org>
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