a univariate or multivariate time series, or a vector, or
a matrix with each column
representing a component series of a multivariate time series.
OPTIONAL ARGUMENTS:
lags:
maximum number of lags to be plotted.
layout:
a two-dimensional vector specifying the layout of the plots per page.
The first number gives the number of rows and the second is
the number of columns.
The default is one figure per page.
head:
character string for a running head.
This will be plotted as a title at the top of each page.
By default, the string "Lagged Scatterplots :" followed
by the name of the data object x is used.
ask:
logical flag: if TRUE, the user will have to hit the return key between pages.
When the graphics device does not stop automatically
between pages, this allows the user to inspect each graph.
SIDE EFFECTS:
lags lagged scatterplots are produced for each column of x.
For a univariate series, x[t] will be plotted against x[t-k]
for k=1,..., lags, producing lags different scatterplots.
These are useful in exploring the autodependence structure of a time series.
WARNING:
While this function is allowed to work for irregular (its) time series, lag plots may be misleading for irregularly spaced time series.