[OSGeo Africa] converting shapefile to get Google extent

[Hanlie Pretorius]

Hi Solly,

I get the following values for the extents in the two coordinate
reference systems:

WGS 84: xMin,yMin 22.7357,-34.2139 : xMax,yMax 30.1947,-30.0018

EPSG:3857: xMin,yMin 2530931.00,-4057554.48 : xMax,yMax 3361260.85,-3503781.21

So the coordinates you gave are in WGS 84 decimal degrees, not the
Google projection (our two sets of values are probably slightly
different because we're not using the same shapefile; I'm using the
Municipal Demarcation Board's data).

To reproject the shapefile from WGS84 to Google projection, I
right-cllicked the file, selected Save as... and clicked Browse... in
the CRS section.

Then I typed EPSG:3857 into the Filter text box and saw WGS84 / Pseudo
Mercator in the description. I selected that CRS (only one should be
visible) and clicked OK.

When you open the reprojected shapefile and zoom to the layer (without
reproject on the fly enabled), you should see coordinates in the range
I quoted above.

Hope this helps.

Cheers
Hanlie

2013/10/11, Solly Vuso <sollyvuso at gmail.com>:
> Thank you Hanlie
>
> It does work after I followed your instruction but it zoom very close even
> though I used the provincal extent , I think I am still missing something
> here.
>
> This is what I see on the metadata
>
> xMin,yMin 22.7357,-34.2139 : xMax,yMax 30.1947,-30.0018
>
>
> On Thu, Oct 10, 2013 at 9:09 PM, Hanlie Pretorius <
> hanlie.pretorius at gmail.com> wrote:
>
>> 1. Load your Ecape shapefile and use the Vector - Research tools -
>> Polygon from layer extent menu to find the extents of the Ecape.
>>
>> 2. Reproject the extent polygon into Google projection (EPSG:3857).
>>
>> 3. Look at the metadata in the properties of the reprojected extent
>> polygon layer to find the min and max X and Y values.
>>
>> Cheers
>> Hanlie
>>
>> > Date: Thu, 10 Oct 2013 18:18:56 +0200
>> > From: Solly Vuso <sollyvuso at gmail.com>
>> > To: Africa local chapter discussions <africa at lists.osgeo.org>
>> > Subject: Re: [OSGeo Africa] converting shapefile to get Google extent
>> >       co-ordinates
>> > Hi
>> >
>> > Can someone assist me I have a provincial shapefile that I want to use
>> > it
>> > for pmapper and geomoose bt am struggling to get the exact extent for
>> > my
>> > province .
>> >
>> > Please assist me to get the right google projections
>> >
>> > Am in Eastern Cape , South Africa and I need the provincial boundary
>> extent
>> > in Google projections
>> >
>>
>
>
>
> --
> Best Regards
>
> Solly Vuso
> Cell:073 3068 170
> Fax:086 555 1270
>
> I may not know what tomorrow holds for me but I do know who holds ma
> tomorrow.....
>