a list, matrix or data-frame with xy-coordinates
of prediction points or a vector with x-coordinates.
y.coords
a vector with y-coordinates. Needed if
argument coords provides only x-coordinates.
...
arguments by or length.out
to be passed to the function rep.
These arguments are used for the x-coordinates and are
default optioons for y-coordinates.
y.by
Optional. by argument for rep to be
used with the y-coordinates.
y.length.out
Optional. length.out argument for
rep to be used with the y-coordinates.
y.along.with
Optional. along.with argument for rep to be
used with the y-coordinates.
Value
An two column data-frame which is on output of expand.grid.