find.shells {rice} | R Documentation |
Find nearby shell-derived dR values
Description
Find the shells closest to a chosen coordinate, and plot the dR values and feeding ecology. Uses the marine database downloaded (30 Aug 2024) from calib.org/marine. See Reimer PJ, Reimer RW, 2001. A marine reservoir correction database and on-line interface. Radiocarbon 43:461-3.
Usage
find.shells(
longitude,
latitude,
nearest = 50,
colour = "dR",
rainbow = FALSE,
size = 2,
mapsize = "large",
mincol = "yellow",
maxcol = "red",
symbol = "feeding",
symbol.legend = TRUE,
ocean.col = "aliceblue",
land.col = rgb(0, 0.5, 0, 0.6)
)
Arguments
longitude |
Longitude of the point. Can only deal with one point at a time. |
latitude |
Latitude of the point. Can only deal with one point at a time. |
nearest |
The number of shell values to be returned. Defaults to 50. |
colour |
The variable to be plotted as colour. Expects a continuous variable. Defaults to 'dR'. |
rainbow |
Whether or not to use a rainbow scale to plot the variable. |
size |
Size of the symbols. Defaults to 2. |
mapsize |
Resolution of the map. Can be "small", "medium" or "large". If the latter, a high-resolution dataset will have to be downloaded using the R package 'rnaturalearthhires'. Since this package is on github but not on CRAN, you will have to download it yourself (using the command devtools::install_github("ropensci/rnaturalearthhires")). Defaults to 'medium' if 'rnaturalearthhires' is not installed, and to 'high' if it is installed. |
mincol |
Colour for minimum values. |
maxcol |
Colour for maximum values. |
symbol |
The variable to be plotted as symbol. Expects a categoric variable. Defaults to 'feeding'. |
symbol.legend |
Whether or not to plot the legend for the symbols. |
ocean.col |
Colour for the oceans. Defaults to |
land.col |
Colour for the land. Defaults to semi-transparent darkgreen: |
Details
This function uses the 'rnaturalearth' package for country maps. If the high-resolution maps are desired, the 'rnaturalearthhires' package must be installed from GitHub.
Value
A dataset with the n nearest dR values, and a plot of their coordinates.
Examples
UK <- find.shells(0, 55, mapsize="medium")
mean(UK$dR)
Caribbean <- find.shells(-70, 20, 30, mapsize="medium")