Adding and editing points#

Before adding points#

GraphX needs a valid calibration and an active dataset before Add/edit points is available. Check that the intended dataset is active in Datasets or Data points: every new point goes there. If the source is detailed or low resolution, enable Precision magnifier from Display before placing points. If you are sampling prescribed X or Y values, configure Axis lock first.

Adding a point#

1. Choose Add/edit points in the graph toolbar.
2. Move the pointer over the source graph. The coordinate overlay shows the intrinsic image location and, once calibrated, the corresponding graph values.
3. Click the position that represents the data value.
4. GraphX adds the point to the active dataset and updates its Data points table.

The click is recorded as a position on the original source image, then converted through the current calibration into graph coordinates. This is why marker placement matters even when the displayed value looks plausible. Use the mouse wheel to zoom around the pointer, Fit image to regain an overview, and middle-mouse drag to pan temporarily without leaving Add/edit points mode.

Editing a point visually#

Click an existing active-dataset marker to enter point-edit mode. GraphX highlights that point, changes the canvas instruction to request its replacement position, and reveals the relevant row in Data points when necessary. Click a new source-image position to move it; GraphX recalculates the graph coordinates and returns to Add/edit points mode.

Escape leaves point-edit mode without moving the point. Delete or Backspace while editing deletes that point. Selecting another dataset also ends point-edit mode, because editing always belongs to the active dataset.

Enter coordinates directly#

While a point is in point-edit mode, its X and Y cells in Data points become editable fields. Their initial values are the full stored coordinates, not the dataset’s formatted display strings. Enter a complete X and Y pair, then press Enter to commit it. Tab follows the normal table field order, and Escape discards the draft and leaves point-edit mode.

GraphX accepts finite numeric input, including scientific notation. It rejects invalid combinations for the current calibration; for example, a logarithmic axis cannot use a non-positive value. The error is shown with the point row so you can correct the draft.

When direct graph coordinates are accepted, GraphX preserves those graph values and calculates the corresponding source-image position through the calibration. Dataset Precision does not round the input. If you recalibrate later, GraphX uses the saved image position as the authoritative location and recalculates the graph coordinates under the new calibration; review directly edited points after recalibration.

Selecting several points#

Selection is limited to the active dataset. Shift-click a marker to toggle that one point. Shift-drag from empty graph space to add every enclosed active-dataset point to the existing selection; this is an additive marquee rather than a replacement selection. A Shift-click on empty graph space clears the current selection.

Selected markers use a compact selection ring so they remain distinguishable without hiding nearby graph content. Use Delete selected, Delete, or Backspace to remove the selected points together. Ordinary clicks on a marker without Shift still enter point-edit mode rather than changing selection.

Deleting points#

The Delete action in a Data points row removes that individual point immediately. Delete/Backspace removes the point currently being edited, while Delete selected and its keyboard shortcuts remove the current selection. Clear all points removes every point in the active dataset only after confirmation.

For points outside the calibrated range, Delete extrapolated offers targeted cleanup rather than requiring manual deletion one row at a time.

Undo and redo#

Undo and Redo in Data points restore point changes in the active workflow, including additions, visual moves, direct coordinate edits, individual and selected-point deletion, clearing, accepted traces, sorting, and extrapolated-point cleanup. This makes it practical to inspect a change on the graph and table before deciding whether to keep it.

Extrapolated points#

A point is extrapolated when its source position lies outside the calibrated X range, Y range, or both. GraphX can still calculate a coordinate there, but the value depends on extending the calibration beyond the reference range and should be treated more cautiously. Extrapolated values have table and marker indications.

Delete extrapolated provides four criteria:

• Outside X removes points beyond the calibrated X range.
• Outside Y removes points beyond the calibrated Y range.
• Outside X or Y removes a point if either coordinate is beyond its range. For example, a point outside X but inside Y is removed.
• Outside X and Y removes only points beyond both ranges. That same point outside X but inside Y is retained.

See Calibration overview for the calibration references that define these ranges.