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ListDensityPlot / CountryData: Small glitch in the 6.0.2 documentation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg88566] ListDensityPlot / CountryData: Small glitch in the 6.0.2 documentation
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Fri, 9 May 2008 03:20:35 -0400 (EDT)
  • Organization: The Open University, Milton Keynes, UK

The documentation for ListDensityPlot contains a very nice example about 
ozone density around the world. To see it, go to either the 
documentation center or the WRIâ??s website

http://reference.wolfram.com/mathematica/ref/ListDensityPlot.html

Then, go to Applications -> â??Show ozone density around the world:â??

Unfortunately,if one evaluates the given example, one gets the following 
error message:

â??CountryData::notprop: {"SchematicPolygon", "Equirectangular"} is not a 
known property for CountryData. Use CountryData["Properties"] for a list 
of properties. >>â??

Indeed, it is easy to check that this is the â??Equirectangularâ?? property 
that has been removed:

StringCases[
   CountryData["Properties"], ___ ~~ "poly" | "equi" | "rect" ~~ ___,
   IgnoreCase -> True] // Flatten

{"FullPolygon", "Polygon", "SchematicPolygon"}

If I am not fooling myself, by removing the disgraced property and the 
surrounding curly braces around the remaining â??SchematicPolygonâ??, one 
get an identical plot (as far as I can judge, of course). For instance,

data = Import[
    "ExampleData/ozonemap.hdf", {"Datasets", "TOTAL_OZONE"}];

ListDensityPlot[Reverse@data, ColorFunction -> "DeepSeaColors",
  AspectRatio -> Automatic, DataRange -> {{-180, 180}, {-90, 90}}]

outlines =
   Table[DeleteCases[CountryData[r, "SchematicPolygon"],
     Polygon[_Missing]], {r, {"SouthAmerica", "NorthAmerica", "Africa",
       "Europe", "Asia", "Australia"}}];

ListDensityPlot[Reverse@data, ColorFunction -> "DeepSeaColors",
  AspectRatio -> Automatic, DataRange -> {{-180, 180}, {-90, 90}},
  Epilog -> {FaceForm[], EdgeForm[Opacity[0.5]], outlines},
  PlotRange -> {{-180, 180}, {-90, 90}}]

The above code has been tested on

$Version -> "6.0 for Mac OS X x86 (64-bit) (February 7, 2008)"

Best regards,
-- 
Jean-Marc


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