Labels
Edit any graph label with MathText — full control over axis, title, and line labels, including Greek symbols, sub/superscripts, and maths.
01Opening the Label Editor
Open it two ways:
- From the File menu — choose Label Editor.
- By clicking directly on the plot — click the label you wish to edit. If a label is blank, click where it would normally appear, near the centre of the corresponding axis or title area.
02Selecting and editing a label
The window has tabs for each label type (axes, title, legend, and line labels).
- Click the tab for the label category you want.
- Select the specific label name from the list.
- The current MathText code appears in the edit box (top left); the formatted result appears in the output box (top right).
Make changes in the edit box — the output preview updates automatically, so you can check your syntax and layout before writing the label back to the plot.
03Using MathText
MathText expressions are enclosed between pairs of $ symbols. Everything inside a $…$ pair is rendered in a mathematical font; text outside is shown in the normal label font.
For example, $\omega$ inserts the lowercase Greek omega (ω). You can combine text and symbols — Amplitude $A_0 \ (mV)$ produces “Amplitude A₀ (mV)“.
04Common symbols and functions
The editor provides quick-insert buttons for common Greek letters, frequently used functions (sin, cos, exp, log, …), and a maths space for spacing within equations. You can also type any symbol or function supported by Matplotlib’s MathText — a full list is on the official MathText reference page.
05Live preview and syntax checking
The output window updates as you type. If the preview doesn’t update correctly, check that:
- Each $ has a matching closing $.
- Function and symbol names are spelled correctly and preceded by a backslash \.
06Line labels and legend entries
You can edit each line label individually. Tick boxes beside each entry control whether that line’s label appears in the legend — so you can selectively show or hide lines in the legend without removing them from the plot.
07Undo and redo
The editor has standard undo and redo — the Undo and Redo buttons, or Ctrl+Z / Ctrl+Y. Each label keeps its own history: undo affects only the label you are editing, and inserting a Greek symbol or function undoes as a single step. Switching to another label and back preserves that label’s history for the session.
08Applying changes
When you finish editing:
- Click Write to apply the change immediately, or
- Simply click another label — the current one is written automatically before switching.
Tip. Always confirm the output preview looks correct before writing — this prevents accidental blank or malformed labels.
09MathText quick examples
| Expression | Renders as | Meaning |
|---|---|---|
| $\alpha, \beta, \gamma$ | α, β, γ | Greek letters |
| $x^2$ or $x^{2a}$ | x², x²ᵃ | Superscript |
| $E_0$ or $E_{ch}$ | E₀, E_ch | Subscript |
| $\frac{a}{b}$ | a ⁄ b | Fraction |
| $\sqrt{x}$ | √x | Square root |
| $\sin(\omega t)$ | sin(ωt) | Function form |
Combine plain text and MathText freely — for example, Intensity $I/I_0$ → “Intensity I / I₀”.
