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Re: [ferret_users] land_detail missing Nunavut

Hi Derek,

In the Ferret package I use continent, country and state border data come from a file geo_borders.cdf which does not appear to have borders for Canada/Nunavut. There would then appear to be a couple of options:

1) the quick & dirty approach -- in the graphic you included in your query the Nunavut border is pretty simple (10-20 lat,lon pairs would seem to do it) so if you had those coords in a simple ascii file (say NunavutBorder.dat) with missing value codes -999 to raise the pen at the water crossings you could use

file/form=free/var=nunlon,nunlat NunavutBorder.dat ; set var/bad=-999 nunlon
plot/o/vs/nolab/line=2 nunlon,nunlat

to add the border to a plot you had already prepared.

2) The "do it right" approach: Clearly what is needed is a variant of "geo_borders.cdf" that includes the extra boundaries. Perhaps someone will already have such a file to share, but if not there is a wealth of free GIS datasets from which it is possible to extract the lat,lon pairs to extend geo_borders or make a separate "canada_borders" file. Doing a Google led me to http://www.weather.gov/geodata/catalog/national/html/province.htm which looks like it would be detailed enough. This, or another GIS dataset, would include a "shapefile" which could be converted to ASCII with a tool like "shpdump". This you would edit to remove all but the lon,lat pairs (and perhaps add an index variable to denote subregion/province) with missing values for "pen-up" as before. This ASCII file you could read into Ferret and use directly, or perhaps output as a netCDF file to distribute to fellow Ferret users with appropriate recognition to the original data source. Or with ncdump/edit/ncgen you could insert it in the datafile "land_detail" employs.

Hope this helps ... perhaps others with related problems if the datafile you need is forthcoming from another user.

Good luck,

Derek Tsui wrote:
Dear Ferret Users,

I am using land_detail to draw boundaries and noticed that the Nunavut boundary is missing. Is there anyway to add this? Do I need to modify land_detail? Any suggestions would help. Thanks,


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