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Question about SDTS format

  • To: mathgroup at smc.vnet.net
  • Subject: [mg102882] Question about SDTS format
  • From: "Elton Kurt TeKolste" <tekolste at fastmail.us>
  • Date: Tue, 1 Sep 2009 03:52:49 -0400 (EDT)
  • References: <200908311033.GAA06953@smc.vnet.net>

The files on the US Government website nationalatlas.gov
(http://nationalatlas.gov/mld/statesp.html) claims to have files in SDTS
format.

In particular, I have downloaded and decompressed the files for the
state data, but Mathematica cannot import them.

For example, after downloading:

In[519]:= Import["Z:\BIGSIGMAA\Data\STAPAPPC.DDF"]

During evaluation of In[519]:= Import::fmterr: Cannot import data as
SDTSDEM format. >>

Out[519]= $Failed

It will read the "Element" field:

In[533]:= elements = 
 Import["Z:\BIGSIGMAA\Data\STAPAPPC.DDF", "Elements"]

Out[533]= {"Centering", "CentralScaleFactor", "CoordinateSystem", \
"CoordinateSystemInformation", "Data", "DataFormat", "Datum", \
"ElevationRange", "Graphics", "GridOrigin", "InverseFlattening", \
"LinearUnits", "Projection", "ProjectionName", "RasterSize", \
"ReferenceModel", "SemimajorAxis", "SemiminorAxis", "SpatialRange", \
"SpatialResolution", "StandardParallels"}

But not any of the elements

In[534]:= map = 
 Import["Z:\BIGSIGMAA\Data\STAPAPPC.DDF", #] & /@ elements

During evaluation of In[534]:= Import::fmterr: Cannot import data as
SDTSDEM format. >>

During evaluation of In[534]:= Import::fmterr: Cannot import data as
SDTSDEM format. >>

During evaluation of In[534]:= Import::fmterr: Cannot import data as
SDTSDEM format. >>

During evaluation of In[534]:= General::stop: Further output of
Import::fmterr will be suppressed during this calculation. >>

Out[534]= {$Failed, $Failed, $Failed, $Failed, $Failed, $Failed, \
$Failed, $Failed, $Failed, $Failed, $Failed, $Failed, $Failed, \
$Failed, $Failed, $Failed, $Failed, $Failed, $Failed, $Failed, \
$Failed}

I can think of three possiblities:
1) I ammisusing Mathematica
2) Mathematica does not actually import SDTS files as advertised
3) The government did not publish this data in SDTS format despite the
data suffix.

Does anyone have any hints as to how to import SDTS data or information
about the formats used by the government?'

Regards,
Kurt Tekolste



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