This function is useful in creating dummy points for quadrature
schemes (see quadscheme
). Given the point pattern specified by the vectors
x
and y
, the function
creates a pattern of nrad * nper * length(x)
dummy points.
Around each data point (x[i],y[i])
there are
nrad * nper
dummy points, lying on nrad
radii
emanating from (x[i],y[i])
, with nper
dummy points
equally spaced along each radius.
The (equal) spacing of dummy points along each radius is
controlled by the factor fctr
.
The distance from a data point to the furthest of its associated
dummy points is fctr * M
where M
is the mean nearest neighbour distance
for the data points.
If the point pattern specified by x
and y
contains
only one point, the nearest neighbour distance is infinite,
so the value Mdefault
will be used in place of M
.