Toolbar
The plot toolbar runs along the bottom of the graph — quick access to formatting, navigation and export. It is based on the standard Matplotlib toolbar, with several CFTool-specific controls added.
01Display controls
The left-hand CFTool controls adjust how the plot is drawn:
- Font Size slider — scales all plot fonts together (axis labels, legend and title), keeping the proportions defined in the Settings dialog. Handy for scaling text for presentations or print without touching individual font settings.
- Line Width slider — changes the thickness of all plotted lines by the same relative amount; the proportions between datasets and fit curves stay fixed. (That ratio is not adjustable yet, but may be in future versions.)
- Legend checkbox — shows or hides the plot legend. With it off, the freed space lets the plot expand slightly.
02The Extend Fit / Fit to Data button
This CFTool control decides whether a line’s fitted curve is drawn only across its data or extended beyond it. It is an action button — its label tells you what a press will do, not the current state:
| Button reads | Current state | A press will… |
|---|---|---|
| Extend Fit | Fit drawn only over the data range | Extend the fitted curve beyond the data |
| Fit to Data | Fit extended beyond the data | Pull the fit back to the data range |
The mode is per line — each line remembers its own setting, so you can extend the primary fit while keeping the secondary one tight — and it is saved with the .cfp project.
Disabled in Full Graph. Because the extension is a per-line property, the button is disabled in Full Graph view (it would affect both lines at once). Switch to Primary Line or Secondary Line to change that line; Full Graph then shows each line in its own mode.
03The Fit Extension dialog
The button’s menu arrow opens Edit Primary Line Extension… (or Secondary Line), which sets how far that line’s fit extends. The extension is a per-line value edited here.
The dialog (titled Fit Extension: <line>) has two fields:
- Left multiplier — how far the fit extends to the left of the data.
- Right multiplier — how far it extends to the right.
Each value is a multiplier of the fitted x-range — bigger means more extension:
| Value | Extension |
|---|---|
| 0.0 | 0% — no extension (fit stops at the data) |
| 0.1 | 10% of the fitted x-range |
| 1.0 | 100% of the fitted x-range |
| 2.0 | 200% of the fitted x-range |
Reset to Default restores the standard extension for both sides.
Menu wording. In Full Graph the menu item is disabled and reads “Edit extension in single-line view.” For a Function Line that tracks the primary, it reads “Function Line follows Primary Line extension” — the function line uses the primary line’s extension rather than one of its own.
04Navigation tools
- Home — restores the plot to its default zoom and pan state.
- Back / Forward — step through previous pan or zoom operations.
- Pan — mouse-drag navigation: left-click drag pans, right-click drag zooms.
- Zoom — drag a box to magnify that region.
Right-click menu. While the Pan or Zoom tool is active, the main-graph right-click context menu is disabled — deactivate the tool to restore it.
05Borders and Spacing
Opens a dialog for fine-tuning the plot layout — margins, spacing and figure balance.
06Plot Settings
Opens the Plot Settings dialog, where you can modify axis limits, line formatting (colours and symbols), and axis labels and tick marks. A small box is provided for the title; for more complex titles or formatted labels, use the Label Editor (which supports MathText, a lightweight LaTeX-style markup).
07Save / Print
Opens the plot in a new window for printing or image export — send it to a printer, or save as PDF, SVG, PNG, EPS and other formats. The window includes sliders for axis formatting, and the exported image adopts that window’s aspect ratio, so resize it to your preferred shape before saving. By default the graph uses an A4 landscape ratio.
08Mouse-position indicator
At the far right of the toolbar, this shows the current cursor coordinates within the plot area — useful for reading off data values or checking fit limits interactively.
Tip. A single click on Home resets both axes to their default full-range view — a quick way to recover from several zoom or pan operations.
