[OSM-talk] "scale" a ShapeFile in Y-direction?

[Torsten Mohr]

Hello,

thanks for taking a look at it.  The output is ~ 19000 lines, so i'll just
show the top ~70 lines:

Had to open data source read-only.
INFO: Open of `world_boundaries_m.shp'
      using driver `ESRI Shapefile' successful.

Layer name: world_boundaries_m
Geometry: Polygon
Feature Count: 3807
Extent: (-20037400.000000, -19929239.110000) - (20037400.000000, 
18375854.709643)
Layer SRS WKT:
PROJCS["Mercator",
    GEOGCS["GCS_WGS_1984",
        DATUM["WGS_1984",
            SPHEROID["WGS_1984",6378137,298.257223563]],
        PRIMEM["Greenwich",0],
        UNIT["Degree",0.017453292519943295]],
    PROJECTION["Mercator_1SP"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",0],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",0],
    PARAMETER["false_northing",0],
    UNIT["Meter",1]]
CAT: Real (16.0)
FIPS_CNTRY: String (80.0)
CNTRY_NAME: String (80.0)
OGRFeature(world_boundaries_m):0
  CAT (Real) =               15
  FIPS_CNTRY (String) = AY
  CNTRY_NAME (String) = Antarctica

OGRFeature(world_boundaries_m):1
  CAT (Real) =               15
  FIPS_CNTRY (String) = AY
  CNTRY_NAME (String) = Antarctica

OGRFeature(world_boundaries_m):2
  CAT (Real) =               15
  FIPS_CNTRY (String) = AY
  CNTRY_NAME (String) = Antarctica

OGRFeature(world_boundaries_m):3
  CAT (Real) =               15
  FIPS_CNTRY (String) = AY
  CNTRY_NAME (String) = Antarctica

OGRFeature(world_boundaries_m):4
  CAT (Real) =               15
  FIPS_CNTRY (String) = AY
  CNTRY_NAME (String) = Antarctica

OGRFeature(world_boundaries_m):5
  CAT (Real) =               15
  FIPS_CNTRY (String) = AY
  CNTRY_NAME (String) = Antarctica

OGRFeature(world_boundaries_m):6
  CAT (Real) =              174
  FIPS_CNTRY (String) = NZ
  CNTRY_NAME (String) = New Zealand

OGRFeature(world_boundaries_m):7
  CAT (Real) =              174
  FIPS_CNTRY (String) = NZ
  CNTRY_NAME (String) = New Zealand

OGRFeature(world_boundaries_m):8
  CAT (Real) =              174
  FIPS_CNTRY (String) = NZ
  CNTRY_NAME (String) = New Zealand


It additionally tells me on stderr:
ERROR 4: Unable to open world_boundaries_m.shp or world_boundaries_m.SHP.


Thanks for any hints,
Torsten.


Am Montag, 11. Mai 2009 12:42:44 schrieb Juan Lucas Dominguez Rubio:
> Hi:
>
> I'm curious about that shapefile that needs some stretching. Assuming its
> name is filename.shp, try to type this:
>
> ogrinfo -geom=NO filename.shp filename
>
> what is the output?
>
> Regards,
> Juan Lucas
>
>
> ________________________________
>
>
>
>
> 		Hello Frederik,
>
> 		thanks for your hint. Yes, i know about projections.  Actually, i
> reprojected the rester images of "blue marble" from a form of WGS84 to
> Mercaator with an own program.
>
> 		But as i've heard it, world_boundaries_m is "defect".  But as an overlay
> 		to represent the boundaries it would be ok.  If that information was a
> 		misunderstanding and could be fixed with the right projection that would
> be awesome.
>
> 		If i use shoreline_300 instead, the projection is perfectly fine, but if
> you try to render it _not_filled_ with a LineSymbolizer instead of a
> PolygonSymbolizer, you get some disturbing "plates".  But the projection is
> fine.
>
> 		A ShapeFile contains the "source SRS" inside it, right?  When rendering
> 		world_boundaries_m and shoreline_300 i used the same "target SRS".
> 		But the result leads to different positions on the final map.
>
> 		Does that mean that world_boundaries_m is defect?
>
> 		Is there a way to "fix" it somehow?  Or would scaling be possible?
>
>
> 		Best regards,
> 		Torsten.
>
> 		> Hi,
> 		>
> 		> Torsten Mohr wrote:
> 		> > I have a ShapeFile that seems to be incorrect, scaling it in
> 		> > Y-direction could make it fit the background.
> 		>
> 		> Do you have a basic understanding of coordinate projections? If not,
> 		> you'd be well advised to spend a few hours reading on the subject
> 		> (start with Wikipedia, take it from there).
> 		>
> 		> You need to find out which projection your shapefile is in, and then
> 		> set the correct one in your map file, and things are likely to work.
> 		> Simply stretching the data from the shapefile is very unlikely to yield
> 		> the desired results - you will probably find that the stretch factor
> 		> that makes Iceland and the Equator fit will still have France out of
> 		> place.
> 		>
> 		> Bye
> 		> Frederik
>
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