Change the scale of graphed data

In the Graph Plots view, you can control the x- and y-scale of the data plotted by selecting options on the toolbar, in context (right-click) menus, and by dragging with the mouse.

Use the toolbar options for scaling

In the Graph Plots view, the graph plot scaling options in the toolbar enable you to control the type of scaling that is possible and whether or not it is locked to prevent further changes.

	To prevent any changes to the x-axis (deactivates pan/zoom and fit), select the Lock x-axis button.
	When you select the Scale to fit x axis button, the axis range is automatically adjusted to fit the data currently stored in the channel cache (see Graph Plots terminology ). When auto-fit is on, the mouse pan/zoom is turned off. Fits to min/max of data range. Tip : Change the channel cache by changing the Live data range field in the bottom right corner of the Graph Plot view. This changes the amount of live data to keep in the memory.
	To prevent any changes to the y-axis (deactivates pan/zoom and fit), select the Lock y-axis button.
	When you select the Scale to fit y axis button, the axis range is automatically adjusted to fit the data currently stored in the channel cache (see Graph Plots terminology ). When auto-fit is on, the mouse pan/zoom is turned off. Fits to min/max of data range + 5% padding

Note
When either of the Scale to fit modes is disabled, the graph axes revert back to their previous (non-fitted) state. This may result in a graph that is not properly scaled and you may need to manually scale or use the context menu to visualize your data again.

An additional option at the bottom right of the Graph Plots view enables you to specify the Live data range. This changes the amount of live data to keep in the memory and essentially controls the size of the channel cache.

The Live data range list enables you to choose the default time axis range (ie, x-axis) and, as a result, the amount of data stored in the channel cache (see Graph Plots terminology).

Note that if the duration of the Pause Buffer Size (Advanced parameter in Processing panel > Output section) is less than the Live data range, selecting a new channel source to create an active channel only displays data initially for the duration of the Pause Buffer Size.

Use the context menu for scaling

In a Graph Plots view, you can right-click to display a context menu.

The context menu options depend on where the right-click occurred:

Graph Plot

Y-axis

X-axis

This table describes the function of each of the options:

Option	Function
Pin Channel	Pins a channel from the current subplot. See Manage channels.
Reset X-Axis	Resets the range of the time axis. This affects the x-axis range for all plots.
Reset Y-Axis	Resets the range of the y-axis of the current subplot
Reset All Y-Axes	Resets the range of all y-axes within the Graph Plot view
Reset All Axes	Resets the range of both the x-axis and y-axis for all subplots within the Graph Plot view.
Relative Time Display	The default time index is always relative to the current frame. Clearing this option displays the time relative to the beginning of the current session.

Use the mouse for scaling

Graph plots have a range setting (where range is the minimum and maximum value on the axis). Zooming changes the length of the range; panning changes the central point of the range.

The following table describes the mouse actions required to zoom or pan a graph plot. For a full list of mouse actions, see Graph Plots mouse actions.

Required zoom or pan	Mouse action
Zoom on a single axis only	Right-click and drag on the required axis.
Zoom on both the x- and y-axis	Right-click within the subplot window and drag the subplot.
Pan on a single axis only	Middle-click and drag on the required axis.
Pan on both the x- and y-axis	Middle-click within the subplot window and drag the subplot. Note that the middle-click can be substituted by the wheel button or by simultaneously pressing both the left and right mouse buttons.

When you zoom or pan, a bold circle is displayed, representing the deadzone. If the mouse pointer is within the deadzone, no zoom or pan change occurs. A faint circle is drawn when the mouse pointer is outside the deadzone, highlighting the current pointer position.

Zoom indicator

Pan indicator

When multiple x-axes are present, zooming or panning one affects all the x-axes (they are linked).

Note
For zooming and panning to work in this way, ensure that neither axis is locked or auto-scaling.
To check, verify that:

The Lock axis buttons and the Scale to fit buttons, both horizontal and vertical ), are not selected.
Show pan/scale overlay graphics is enabled in Preferences (see Live - Set preferences).