get_itrdb

A Raster* or Spatial* object to serve 
as a template for selecting chronologies. If missing, 
all available global chronologies are returned.

template

A character string naming the study area.

label

A numeric vector of years over which reconstructions are needed; 
if missing, the union of all years in the available chronologies are given.

recon.years

A numeric vector of all required years---chronologies without these years will be discarded; 
if missing, all available chronologies are given.

calib.years

A character vector of 4-letter tree species identifiers; 
if missing, all available chronologies are given.

species

A character vector of measurement type identifiers. Options include:
<ul>
<li> "Total Ring Density"
</li>
<li> "Earlywood Width"
</li>
<li> "Earlywood Density"
</li>
<li> "Latewood Width"
</li>
<li> "Minimum Density"
</li>
<li> "Ring Width"
</li>
<li> "Latewood Density"
</li>
<li> "Maximum Density"
</li>
<li> "Latewood Percent"
</li>
</ul>if missing, all available chronologies are given.

measurement.type

A character vector of chronology type identifiers. Options include:
<ul>
<li> "ARSTND"
</li>
<li> "Low Pass Filter"
</li>
<li> "Residual"
</li>
<li> "Standard"
</li>
<li> "Re-Whitened Residual"
</li>
<li> "Measurements Only"
</li>
</ul>if missing, all available chronologies are given.

chronology.type

Should the metadata be presented as a SpatialPointsDataFrame? Defaults to FALSE.

makeSpatial

A character string indicating where raw downloaded files should be put.
The directory will be created if missing. Defaults to "./RAW/ITRDB/".

raw.dir

A character string indicating where the extracted and cropped ITRDB dataset should be put.
The directory will be created if missing. Defaults to "./EXTRACTIONS/ITRDB/".

extraction.dir

If an extraction already exists, should a new one be created? Defaults to FALSE.

force.redo

<code>get_itrdb</code> returns a named list of length 3: 
<ol>
<li> "metadata": A data.table or <code>SpatialPointsDataFrame</code> (if <code>makeSpatial==TRUE</code>) of the locations 
and names of extracted ITRDB chrononlogies,
</li>
<li> "widths": A matrix of tree-ring widths/densities given user selection, and
</li>
<li> "depths": A matrix of tree-ring sample depths.
</li>
</ol>

Functions to automate downloading geospatial data available from
several federated data sources (mainly sources maintained by the US Federal
government). Currently, the package allows for retrieval of five datasets:
The National Elevation Dataset digital elevation models (1 and 1/3 arc-second;
USGS); The National Hydrography Dataset (USGS); The Soil Survey Geographic
(SSURGO) database from the National Cooperative Soil Survey (NCSS), which is
led by the Natural Resources Conservation Service (NRCS) under the USDA; the
Global Historical Climatology Network (GHCN), coordinated by National Climatic
Data Center at NOAA; and the International Tree Ring Data Bank. Additional
data sources are in the works, including global DEM resources (ETOPO1, ETOPO5,
ETOPO30, SRTM), global soils (HWSD), MODIS satellite data products, the National
Atlas (US), Natural Earth, PRISM, and WorldClim.

get_itrdb: Download the latest version of the ITRDB, and extract given parameters.

Description

Usage

Arguments

Value