R help - May 2018 - mapping groups of states without interior borders

I have been using the "map" function in R and I was wondering if there
is a way to map multi-state regions just showing the outline of the region
without interior state borders.  For instance, I am calculating aggregated
statistics using 10 multi-state regions.  I would like to color-code individual
states based on my dataset but then to create black outlines around each of
these 10 regions so that the map shows the delineations of the various regions
for which I am reporting aggregated statistics.

When I use:
map('state', region = "Idaho", "Washington",
"Oregon", add = TRUE, color = "black")
I get a plot that includes interior boundaries between these 3 states instead of
an exterior border around this region.

Thanks,
Heather

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Presumably this is in the package maps?? -- you need to specify such
details when referring to non-base R functionality.

In any case, you are more likely to get a helpful response if you post to
the  r-sig-geo list, which specialized in such spatial statistics/graphics
questions.


Cheers,
Bert



Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Mon, May 21, 2018 at 10:02 AM, Simon, Heather <Simon.Heather at
epa.gov>
wrote:
> I have been using the "map" function in R and I was wondering if
there is
> a way to map multi-state regions just showing the outline of the region
> without interior state borders.  For instance, I am calculating aggregated
> statistics using 10 multi-state regions.  I would like to color-code
> individual states based on my dataset but then to create black outlines
> around each of these 10 regions so that the map shows the delineations of
> the various regions for which I am reporting aggregated statistics.
>
> When I use:
> map('state', region = "Idaho", "Washington",
"Oregon", add = TRUE, color > "black")
> I get a plot that includes interior boundaries between these 3 states
> instead of an exterior border around this region.
>
> Thanks,
> Heather
>
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>
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