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All the plot windows are interactive, and you can navigate around
them using the mouse buttons. For most plot types the left and right
buttons and the mouse wheel do something;
in 3d plots the middle button is used as well.
The details of what mouse actions do what depend on which plot
window you are using, and they can also be configured to some extent
using the Navigation tab in the Axes
fixed control in the control stack.
However, as a rule, the actions when used on the body of the plot are these:
-
Left drag
- Drags the plot around. Where possible, the same plot position
stays under the cursor as you drag. In 2d this pans the plot
left/right/up/down, and in 3d it rotates it.
-
Right drag
- Stretch zoom.
Dragging up/down stretches/squashes the plot vertically, and
dragging left/right stretches/squashes it horizontally.
The zoom is centered on the position where you start the drag from,
so that data position stays in the same place on the screen.
In 3d, the zoom is along the two plot directions most closely
aligned with the plane of the screen.
-
Middle drag
- Frame zoom.
Dragging right-and-down or right-and-up drags out a frame;
when the button is released, the plot will be zoomed in
to cover area enclosed by the frame.
Dragging left (and up or down) does something like the opposite,
you can zoom out using a similar (though not quite the same) mechanism.
-
Mouse wheel
- Spinning the mouse wheel forwards/backwards will zoom in/out.
In 2d the zoom is around the current position of the mouse,
and in 3d it is (usually) around the center of the view cube.
-
Left click
- Identifies a point. If there is a plotted point near the cursor,
it will plot a marker on it and
activate it.
If you click on an empty bit of the plot, any existing activated point
will be removed, otherwise nothing will happen.
In the 2d plot types, you can pan or zoom in just one direction
by using the same actions outside of the plot itself.
If you do a pan/zoom action to the left of the Y axis, it will pan/zoom
only vertically, and if you do it below the X axis, it will do it only
horizontally.
Most of these actions give you some visual feedback on the screen,
showing a rectangle or some arrows to give you a clue what you're doing.
If you find that distracting, you can turn it off using the
Plot|Show Navigation Graphics () menu item.
Navigation help panel at the bottom of plot windows
In each plot window there is a row at the bottom of the window
giving hints on the currently available navigation actions.
The little icons are each supposed to represent either a
click () or a drag ()
with one of the three buttons pressed,
or a wheel spin (),
and are followed by a short description of what it will achieve.
Note these hints change according to where the mouse is currently
positioned on the screen.
Moving the button over this panel will give you some help on the help.
Clicking the button will make the line disappear,
and you can bring it back with the Window|Show Navigation Help
() menu item.
The button will bring up a help window specific to
the navigation in this window.
If you are using a mouse with fewer than three buttons or no wheel,
the following subsitute gestures can usually be used:
-
Left button
- If you only have one button, this is it.
-
Right button
- If you only have one button, you can use it with the CTRL key.
-
Middle button
- If you only have one button, you can use it with the SHIFT key.
If you have two buttons, sometimes pressing them both at once will work.
-
Wheel
- Often a wheel action can be simulated on a trackpad by moving
two fingers together up or down.
Next Previous Up Contents
Next: Table Data Layer Controls
Up: Plot Window Overview
Previous: Plot Window Overview
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:
topcat-user@jiscmail.ac.uk