[R] Blank certain areas of a contour plot

[Greg Snow]

After you have interpolated your data, replace the values in the areas of the ocean with NA, then filled.contour will not plot in those areas.

Hope this helps,

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Victor Homar
> Sent: Tuesday, September 16, 2008 9:54 AM
> To: r-help at r-project.org
> Subject: [R] Blank certain areas of a contour plot
>
> Hi,
>
> I'm interpolating a list of syncronous accumulated precipitation
> observations collected over a number of raingauge stations sited over
> land, over a regular lat/lon grid using akima's interp().
>
> Then, I plot and locate geographycally the resulting field with a
> filled.contour() and a call to map(). Everything is fine but I need to
> "blank" (in Golden Surfer nomenclature) the areas of my domain that lay
> over the sea, as I do not have observations there and structures are
> completely artificial.
>
> Is there any function out there that can use the mapsdata database to
> "blank" the sea areas of my plot?
> Otherwise, can anybody think of a shortcut to get a similar effect on
> the final map (not showing the interpolated precipitation areas over
> the
> sea?
>
> Thanks a lot in advance,
>
> Víctor.
>
> --
> -----------------------------------------------------------------------
> Víctor Homar Santaner
> Grup de Meteorologia
>
> Edif. Mateu Orfila                      Tel: +34 971 17 1376
> Universitat de les Illes Balears        Fax: +34 971 17 3426
> 07122 Palma de Mallorca (SPAIN)         Email: Victor.Homar at uib.es
>
>               Knowledge is contagious. Infect truth.
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