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The Vector form ()
plots directed lines from the
data position given delta values for the coordinates.
The plotted markers are typically little arrows, but there are
other options.
In some cases such delta values may be the actual magnitude required
for the plot, but often the vector data represents a value which
has a different magnitude or is in different units to the positional data.
As a convenience for this case, the plotter can optionally
scale the magnitudes of all the vectors to make
them a sensible size (so the largest ones are a few tens of pixels long).
This scaling can be adjusted or turned off using the
Scale and Auto Scale options below.
Example XYVector plot
Vector form configuration panel
The configuration options are:

Shading Mode
 See Appendix A.4.6.

DeltaX, DeltaY, ...
 The coordinates of the changes in each coordinate which gives the
vector. The coordinates here match the coordinates of the plot.

Arrow
 Arrow shape selected from a range of options.

Scale
 Changes the factor by which all vector sizes are scaled.
If the arrows are too small, slide it right, if they are too big,
slide it left. The slider scale is logarithmic.
Alternatively, enter a fixed value in the text field.

Auto Scale
 If selected, this option will determine the default arrow scale size
from the data  it will fix it so that the largest arrows are a
few tens of pixels long by default.
That scaling can then be adjusted using the Scale slider.
If unselected, then the default position of the Scale slider corresponds
to the actual positions given by the submitted delta coordinates.
Next Previous Up Contents
Next: SkyVector Form
Up: Plot Forms
Previous: SizeXY Form
TOPCAT  Tool for OPerations on Catalogues And Tables
Starlink User Note253
TOPCAT web page:
http://www.starlink.ac.uk/topcat/
Author email:
m.b.taylor@bristol.ac.uk
Mailing list:
topcatuser@jiscmail.ac.uk