Coords tab of plane Axes control

The Coords tab controls the axis coordinates. It has the following options:

X/Y Log

If selected, horizontal/vertical axis coordinates are logarithmic, otherwise they are linear.

X/Y Flip

If selected, horizontal/vertical axis coordinate axes run in the opposite direction to normal.

Aspect Lock

If selected, the number of pixels per unit is always the same on both axes, i.e. the unit square is always a square. Otherwise, there is no constraint on the relative sizes of the X and Y axis units.

Navigation tab of plane Axes control

The Navigation tab controls details of how the navigation works. It has the following options:

Pan/Zoom Axes

Normally, dragging with the left/right mouse buttons or using the mouse wheel on the main part of the plot will pan/zoom it in both X and Y directions. By unchecking the X or Y checkbox here, you can prevent pan/zoom in the corresponding direction, so if the Y box is unchecked, pan/zoom will only affect the vertical direction (note the same effect can be achieved by dragging to the left of the Y axis).

Anchor X/Y axis

Normally, zoom operations zoom around the position of the mouse at the start of the wheel/drag gesture. Checking these boxes fixes the X/Y reference coordinate for zooms to be the Y=0 or X=0 lines. This can be useful if you want the X or Y axis to stay put (e.g. at the edge of the plot) during zoom actions.

Zoom Factor

Controls the factor by which each zoom action zooms the plot. Moving this slider to the left/right makes the mouse more/less sensitive (one wheel click or dragging a fixed distance has more/less zoom effect).

Range tab of plane Axes control

The Range tab provides manual configuration of the visible range of the plot. Making changes to this tab will reset the visible plot range, but not vice versa - zooming and panning in the usual way will not change the settings of this panel.

Filling in the Minimum/Maximum fields for either or both axes will constrain the corresponding range of the visible data. The limits corresponding to any of those fields that are left blank will initially be worked out from the data. The Subrange double-sliders restrict the ranges within the (explicit or automatic) min/max ranges. Note you can move both sliders at once by grabbing a position between the two.

The Clear button resets all the fields.

Grid tab of plane Axes control

The Grid tab configures the appearance of the axis grid. It has the following options:

Draw Grid

If true, grid lines will be drawn across the plot for every tick mark.

Grid Colour

Selects the colour with which grid lines will be drawn.

Grid Transparency

Controls the transparency of the grid lines, which are drawn over the plot content.

Label Colour

Selects the colour in which axis label text will be written.

Minor Ticks

If set, minor (unlabelled) tick marks will be drawn between the major (labelled) ones.

Shadow Ticks

If set and no secondary axis is in use, then tick marks without numeric labels are painted along the axis opposite to the primary axis, so that tick marks are visible along all edges not just the ones with numeric labels. If a secondary axis is in use, this setting is ignored.

X/Y Tick Crowding

Use the slider to influence how many tick marks are draw on each axis.

Labels tab of plane Axes control

The Labels tab controls the text labels on the axes. If the Auto checkbox is set, the text will be taken from one of the data coordinates being plotted on that axis. To override those with your own axis labels, unset Auto and type text in to the Label fields.

Secondary tab of plane Axes control

The Secondary tab controls optional secondary X and Y axes at the top and right edges of the plot, to go with the standard (primary) X and Y axes at the bottom and left edges, so you can annotate a plot for instance with both magnitudes and fluxes, or both frequency and wavelength.

Secondary X/Y Axis f(x/y)

Defines the secondary axis in relation to the primary one by means of a supplied function that maps primary to secondary axis values, written using TOPCAT's expression language. For the Secondary X axis this is given as a function of the dummy variable x, and for the Secondary Y axis as a function of the dummy variable y. The function supplied should be monotonic and reasonably well-behaved, otherwise the secondary axis annotation may not work well. TOPCAT will attempt to make a sensible decision about whether to use linear or logarithmic tick marks.

Secondary X/Y Axis Label

Provides a textual annotation near the secondary axis. This can be supplied whether or not the axis mapping functions are actually present.

Font tab

The Font tab configures the font used for axis annotation. It also affects some other things like the legend.

Text Syntax

How to turn the text into characters on the screen. Plain and Antialias both take the text at face value, but Antialias smooths the characters. Antialiased text usually looks nicer, but can be perceptibly slower to plot. At time of writing, on MacOS antialiased text seems to be required to stop the writing coming out upside-down for non-horizontal text. LaTeX interprets the text as LaTeX source code and typesets it accordingly.

Font Size

Size of the font in points.

Font Style

Style of the font.

Font Weight

Whether the font is plain, bold or italic.