Micha Silver wrote:
David
J. Bakeman wrote:
Micha Silver wrote:
David J. Bakeman wrote:
I have some shape files that are in
seconds rather than decimal
I'm not sure what you mean here. A shapefile is not "in seconds" or
"decimal degrees". The geometry part (*.shp) is a binary representation
of X-Y coordinates, as simple numbers. If the shapefile also has a
*.prj file, then that should contain its projection information.
If you have attribute columns (in the *.dbf part of the shapefile) with
X-Y coordinates, then you can format these columns any way you like
using, for example, Openoffice Calc. But this will *have no effect* on
the geographic location of the features in the shapefile.
So, the important question is: do the shapefiles overlay correctly? If
not, then you need to reproject one shapefile to the projection of the
others.
Hope that's clear...
Sorry I didn't make myself clearer. The shapefiles are missing the prj
files and the coordinates of the geometry are in seconds for example
72.5 34.5 would be 261000.0 124200.0. I can write a quick program to
convert since it's a simple /3600 but it seemed like I should be able
to have qgis do it for me if I could figure out the correct proj
specification. I have used the transformation plugin in the meantime
to scale the data by 1/3600.
That will be a first for me! I've never seen LON/LAT coordinates
specified in seconds.
If you're lacking a *.prj then you will have to know in advance what
CRS these shapefiles are in. Again, if you display them by assuming
everything is in Lon/Lat WGS84, do they overlay correctly?
I'm not sure why it was done that way but it is
WGS84 with lat lon in seconds and if I transform them by dividing by
3600 they overlay perfectly. It just seemed like I ought to be able to
do it with the correct CRS spec but being a novice at understanding the
spec I've no clue how to do it. I tried specifying a unit and a scale
factor +k_0= but neither seems to do anything.
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