Converts the dataset x
to a line segment pattern
(an object of class "psp"
; see psp.object
for
an overview). This function is normally used to convert an existing line segment pattern
dataset, stored in another format, to the "psp"
format.
To create a new point pattern from raw data such as $x,y$
coordinates, it is normally easier to use the creator function
psp
.
The dataset x
may be:
- an object of class
"psp"
- a data frame with columns named
x0, y0, x1, y1
that will be interpreted as the coordinates of the endpoints
of the segments - a data frame or matrix with exactly 4 columns
that will be interpreted as the coordinates
x0, y0, x1, y1
of the endpoints of the segments - a data frame with columns named
xmid, ymid, length, angle
that will be interpreted as the coordinates of the segment
midpoints, the lengths of the segments, and the orientations of the
segments in radians - a structure with elements named
x0, y0, x1, y1
or elements namedxmid, ymid, length, angle
which will be interpreted as above.
The argument window
is converted to a window object
by the function as.owin
. The argument fatal
indicates what to do when
the data cannot be converted to a line segment pattern.
If fatal=TRUE
, a fatal error
will be generated; if fatal=FALSE
, the
value NULL
is returned.
The function as.psp
is generic, with methods for the
classes "psp"
, "data.frame"
, "matrix"
and a default method.
Point pattern datasets can also be created by the function
psp
.