--- In [email protected], Daniel Morissette <[EMAIL PROTECTED]>
wrote:
>
> gsrao456 wrote:
> > Hi All
> >
> > Apologies if this has been already discussed in the past.
> >
> > I am a new member of this group. I have just started
> > using MITAB.
> >
> > Actually when we try to convert a surpac string file with large
> > coordinates (1e7), the coordinates are set to a default value of
> > 1000000. Is this a bug in mitab library, if yes is there any
> > workaround to come across this problem.
> >
>
> Not really a bug, but a "feature" of the TAB format.
>
> TAB datasets store the object coordinates in the file using
integers.
> The overall bounds of the dataset are scaled to fit in the integer
range
> of +/-1000000000 (+/-1e9). If you don't explicitly provide bounds
then
> MITAB tries to use some default value depending on the dataset's
> coordsys. You are likely hitting that limit because the default
bounds
> for the coordsys that you chose are not large enough for the range
of
> coordinates of your data.
>
> You'll have to explicitly specify bounds that are large enough for
your
> data at the time that you create the dataset, if you use the C
API, then
> see mitab_c_create()'s north, south, east, west args:
> http://mitab.maptools.org/mitab-docs/mitab__capi_8cpp.html#a12
>
> Daniel
> --
> Daniel Morissette
> http://www.mapgears.com/
>
Thanks for an immediate response
Now after setting the bounds I am getting a different problem.The
coordinates of the points in the tab file are very large compared to
the original file.
The coordinates of the original points are
y x
1, 7927669.700, 247130.134
1, 7927670.316, 247128.328
1, 7927669.661, 247125.000
1, 7927670.408, 247120.488
1, 7927671.949, 247116.404
1, 7927672.088, 247114.728
1, 7927668.857, 247112.239
1, 7927666.361, 247111.317
1, 7927665.050, 247110.994
1, 7927662.097, 247110.589
I am using C++ API for writting a TAB file.
I have set the bounds using the setBounds function()
if (file->Open(fname, "wb") == 0) {
file->SetBounds(247108.893, 7927649.353, 247131.979,
7927672.088);
}
Can you please advise me about setting the bounds if i am
wrong, and whether I should set the coordsys also before setting the
bounds.
Thanks
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