skel.plot {dplR}  R Documentation 
Skeleton Plot
Description
Automatically generates a skeleton plot of treering data.
Usage
skel.plot(rw.vec, yr.vec = NULL, sname = "", filt.weight = 9,
dat.out = FALSE, master = FALSE, plot = TRUE)
Arguments
rw.vec 
a 
yr.vec 
optional 
sname 
an optional 
filt.weight 
filter length for the Hanning filter, defaults to 9 
dat.out 

master 

plot 

Details
This makes a skeleton plot – a plot that gives the relative growth for
year t
relative to years t1
and
t+1
. Note that this plot is a standard plot in
dendrochronology and typically made by hand for visually crossdating
series. This type of plot might be confusing to those not accustomed
to visual crossdating. See references for more information. The
implementation is based on Meko’s (2002) skeleton plotting approach.
The skeleton plot is made by calculating departures from high
frequency growth for each year by comparing year t
to the
surrounding three years
(t1
,t
,t+1
). Low frequency
variation is removed using a hanning
filter. Relative
growth is scaled from one to ten but only values greater than three
are plotted. This function’s primary effect is to create plot with
absolute units that can be printed and compared to other plots. Here,
anomalous growth is plotted on a 2mm grid and up to 120 years are
plotted on a single row with a maximum of 7 rows (840 years). These
plots are designed to be plotted on standard paper using an
appropriate device
, e.g., postscript
with defaults or to
pdf
with plot width and height to accommodate a landscape plot,
e.g., width = 10
, height = 7.5
,
paper = "USr"
. These plots are designed to be printable
and cut into strips to align long series. Statistical crossdating is
possible if the data are output but more easily done using the functions
xskel.plot
and xskel.ccf.plot
.
Value
This function is invoked primarily for its side effect, which is to
produce a plot. If dat.out
is TRUE
then a
data.frame
is returned with the years and height of the
skeleton plot segments as columns.
Author(s)
Andy Bunn. Patched and improved by Mikko Korpela.
References
Stokes, M. A. and Smiley, T. L. (1968) An Introduction to TreeRing Dating. The University of Arizona Press. ISBN13: 9780816516803.
Sheppard, P. R. (2002) Crossdating Tree Rings Using Skeleton Plotting. https://www.ltrr.arizona.edu/skeletonplot/introcrossdate.htm.
Meko, D. (2002) TreeRing MATLAB Toolbox. https://www.mathworks.com/matlabcentral/.
See Also
Devices
, hanning
,
xskel.plot
, xskel.ccf.plot
Examples
library(utils)
data(co021)
x < co021[,33]
x.yrs < time(co021)
x.name < colnames(co021)[33]
## On a raw ring width series  undated
skel.plot(x)
## On a raw ring width series  dated with names
skel.plot(x, yr.vec = x.yrs, sname = x.name, master = TRUE)
## Not run:
library(grDevices)
## Try crossdating
y < co021[, 11]
y.yrs < time(co021)
y.name < colnames(co021)[11]
## send to postscript  3 pages total
fname1 < tempfile(fileext=".ps")
print(fname1) # tempfile used for PS output
postscript(fname1)
## "Master series" with correct calendar dates
skel.plot(x, yr.vec = x.yrs, sname = x.name, master = TRUE)
## Undated series, try to align with last plot
skel.plot(y)
## Here's the answer...
skel.plot(y, yr.vec = y.yrs, sname = y.name)
dev.off()
unlink(fname1) # remove the PS file
## alternatively send to pdf
fname2 < tempfile(fileext=".pdf")
print(fname2) # tempfile used for PDF output
pdf(fname2, width = 10, height = 7.5, paper = "USr")
skel.plot(x, yr.vec = x.yrs, sname = x.name, master = TRUE)
skel.plot(y)
skel.plot(y, yr.vec = y.yrs, sname = y.name)
dev.off()
unlink(fname2) # remove the PDF file
## End(Not run)