[R] Beginner plot and map questions

From: Web User <webuser_at_globe.gov>
Date: Sat 15 Oct 2005 - 05:57:55 EST


I have not been able to find answers to these questions in the FAQs, manuals, or R-help archives. If answers are available somewhere, please direct me to them.

1.) Is there a way to convert a table (e.g. represented as a data frame) to a function, specifying which columns are input and which column is output? It would seem that this would be useful for plotting experimental results, since e.g. contour(x, y, f) requires f to be a function.

2.) If x is longitude and y is latitude, then I would think that contour(x, y, f) could be used to create a contour map with equally spaced latitude and longitude. And I've seen that the "maps" and "mapproj" packages can be used to create maps in different projections. a.) Once a base map is created and experimental data is projected to fit the base map, how is it added onto the map? b.) Is there a way to combine the contouring and projection functionality to get contour maps in any of the supported projections?

3.) What algorithm is used by the contour() function? Are there any parameters that can be changed, such as radius of interest for a data point to affect a grid point?

Thanks for any help or references.

R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Oct 15 06:04:17 2005

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