Plots created in Waveform Viewer can be annotated with labels to indicate features of interest or to otherwise convey information to human readers.

Note that you can see and work with labels only if their display is switched on, which is indicated by the activated state of the Show/Hide Labels toolbar button: . If the button is not activated (), click it to show labels before you work with them. (This does not affect axis labels, which are always visible.)

Note, too, that standard and point labels can only be added to the selected plot. Select the desired plot before using either of these tools.

Standard labels

Standard labels are similar to Post-it notes that you can pin on a plot. They are anchored to a spot on the plot where you click the tool and are scrolled with the plot. If the plot is zoomed, they remain the same size. If the plot is deleted, the label is also deleted.

To add a label to the selected plot, make sure that labels are displayed (see above) and click the toolbar button. This opens the Label dialog in which you can enter the text that you want to display. You can also specify the font and background color of the label, as well as its orientation and the alignment of the text within the label. When you click OK in the dialog, the mouse pointer indicates you note text, and clicking in the selected plot positions the label there.

To reposition an existing label, drag it around with the mouse.

To edit the text or style of a note, double-click it. This opens the Label dialog in which you can make changes as desired.

To delete a label, select it and click in the toolbar.

Point labels

Point labels are very similar to standard labels, and most of the information given above also applies to them. The main difference is that point labels include a line which is anchored to a point of the plot. They also add a box around the label text.

Therefore you click twice when creating a point label: The first click positions the anchor point where the line starts, and the second click positions the box with the text.

When repositioning point labels, dragging the text repositions it but leaves the anchor point where it is, and dragging the point leaves the text where it is. Dragging the connecting line repositions all elements together.

Annotating axes

While labels cannot be attached to axes with the label tools, you can add titles or other descriptive text in the axis settings.

To do so, select the axis that you want to label and choose Tools > Axis Settings or click in the toolbar. (For details on selecting an axis, see Working with axes .) In the Axis Settings dialog that opens, check the Custom option in the X Axis Label or Y Axis Label section, respectively, and enter the text in the text field. If you want to show the custom text in place of (as opposed to in addition to) the standard axis label, uncheck the Standard option.