
Select properties for the vector overlay:
 Polar coordinates, or x and y compenents. The
appropriate option depends on the data set.
 Thin: if there are a lot of points close together, you can plot only
every nth record to make the map clearer. If this value is too
large, you may not see enough vectors to understand the patterns.
Larger values will also be faster to plot.
 Fields to use for direction and magnitude, or u and v components. The
direction is assumed to be the direction in which the vector points.
 Line width and color. Color only applies if you
select "Specified" for the color display.
 Line multiple. This will be multiplied by the value in the
magnitude field of the data base, and give the length in pixels of the line.
 Color by max speed: set this value, and the rainbow color range will
go from 0 to this value.
 Arrowhead on the vector. or not.
 Reverse arrows: for the direction of the vector for the arrowhead.
This is appropriate for winds, which are by convention given as the
direction from which the wind blows.
 Autospace: insures the min spacing in pixels
separates adjacent vectors. This should only be used for data sets
on a regular grid.
