reads a vector map of points and writes the same points but
perturbs the eastings and northings by
adding either a uniform or normal delta value. Perturbation means that
a variating spatial deviation is added to the coordinates.
The uniform distribution is always centered about zero.
The associated parameter is constrained to be positive and
specifies the maximum of the distribution; the minimum is
the negation of that parameter. Do perturb into a ring around the
center, the minimum parameter can be used.
Usually, the mean (first parameter) of the normal
distribution is zero (i.e., the distribution is centered at
zero). The standard deviation (second parameter) is
naturally constrained to be positive.
Output vector points are not guaranteed to be contained within the
current geographic region.
James Darrell McCauley
when he was at:
Random number generators originally written in FORTRAN by Wes Peterson and
translated to C using f2c.
Last changed: $Date$