Martin Olney wrote:
> Is there any documentation for the LineSmoother Transformer?
This is from the interactive manual (F1)
LineSmoother
NEW!
Category: Manipulators
Smooths the feature's boundary lines by determining a new location for
each vertex.
Smoothing Algorithm:
The McMaster algorithm calculates a new location for each point by first
taking the average value of the x and y coordinates of the point and a
number of neighboring points. It then slides the averaged point towards
the original point according to a specified displacement value. The
overall effect is that each point will be pulled towards its neighboring
points. Note that for lines, the McMaster algorithm does not change the
first and last N points (where N is the number of neighbors), because
they don't have enough neighbors for the averaging calculations to work
with. A wrap-around is used with polygons, so each point in a polygon
will be changed. In the case of adjacent polygons, collinear portions of
their boundaries will be smoothed together. The remaining parts of their
boundaries will be smoothed as lines. This means that no wrap-around
will be used for adjacent polygons.
The McMaster Weighted Distance algorithm performs the same operations as
the McMaster algorithm only it uses inverse distance weighting to take
into account the distance from each neighbor to the point being moved.
The overall effect is that points further away will have less "pull"
than points close by. The McMaster Weighted Distance algorithm takes a
Weighting Power as an additional parameter. The Weighting Power is used
to determine the weight of each neighboring point.
The Number of Neighbors parameter specifies the number of neighbors to
consider for each point. For example, a value of 2 specifies that the 2
points to the left of each point, the point itself, and the 2 points to
the right will be considered.
The Displacement Percentage parameter specifies the location between the
original and average points to move the point. For example, a value of
50 will place the point at the halfway point between the averaged point
and the point's original location.
Alternatively, the AreaGeneralizer transformer can be used to simplify
area features without modifying each vertex's location.
--
Hans van der Maarel
Red Geographics
www.redgeographics.com / [EMAIL PROTECTED]
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