You view and manipulate various values of one or more selected items (such as the x, y, and z components of a marker trajectory) against time.
The Graph view pane contains the following components.
Graph view pane tool bar
You manage the display of graph data in the workspace with the following controls and buttons on the Graph view pane tool bar at the top of the view pane. The Graph view pane tool bar is designed to lead you left to right through the normal flow of operations required to plot a graph for the selected elements.
You select the type of graph to be displayed in the workspace from under the categories in this drop-down list (graph types that are not available for the current selection are dimmed):
Components – Displays graphs for the components of analog signals from force plates, or other analog devices, such as EMG devices or accelerometers.
Quality – The RMS error of a rigid body compared to its model (VSK).
Differentiate the Graph
You specify for the displayed graph the current variable, its first derivative (velocity or angular velocity), or its second derivative (acceleration or angular acceleration) by selecting the desired options from this drop-down list:
You specify the components of the selected graph type to be plotted in the active Graph view pane by selecting the required options from this drop-down list (only components that you have selected for graph view are available):
If you select an object on the Object tab in the Resources pane, you can select Global Angle from the Graph view tool bar. This enables the Rotation Order button. Clicking on the Rotation Order button lists the angle convention choices of Helical (default), XYZ, XZY, etc. This enables you to choose either a Helical or an Euler angle convention. The Euler angle convention itself has multiple rotation order conventions represented by XYZ, XZY, etc.
This button allows you to show a legend to the right of the graph trace for each component being plotted.
You manage the scale of the graph (to ensure that the desired portions of the selected traces are visible) with these buttons:
Zoom out the x-axis to show the complete range of the trace for 100 frames. This is useful if you have zoomed in a long way and now want to quickly see the entire graph again.
Lock Horizontal Axis
Lock the horizontal graph axis so that the current zoom level is maintained.
Scale the y-axis so that all the data in selected traces for the currently visible x-axis is visible. If there are multiple traces in the selected components, they are all set to the same range required to show all the data for all traces.
Lock Vertical Axis
Lock the vertical graph axis so that the current zoom level is maintained.
Fit Both Horizontally & Vertically
Scale the x and y axes simultaneously to fit the horizontal and vertical ranges of data.
Lock/Unlock Selection Set
Lock the current Graph view pane, so that it is effectively detached from the selection set and is not affected by any subsequent selections in other open view panes. This is useful for displaying different elements in multiple Graph view panes.
Graph view pane workspace
You view and manipulate graph data in the workspace.
The workspace contains rulers and axes along the right and bottom edges and graph traces for the item being plotted.
The y-axis vertical ruler is on the right side of the graph and the x-axis horizontal ruler is below the graph. The y-axis represents the selected component. The x-axis represents the time (in frames). It starts on the right side, which is labeled 0 (current frame) and is labeled from right to left with decreasing negative values to reflect the number of frames away from the live frame.
Viewing data in Graph view
You can display graphs of motion capture data in the Graph view pane.
The Graph view pane displays graphs for the types of data that can be produced in a motion capture trial.
Graphs of trajectories data display three graphs of the X, Y, and Z components of trajectories for two or more selected 3D markers, or a single graph of the trajectory count for all 3D marker trajectories, against time. This is useful for analyzing 3D marker trajectories and identifying gaps to be filled.
To view 3D trajectories in a graph:
- Stream live camera data.
- Select the markers to be graphed in either of the following ways. (The number of markers you select depends on the type of graph you want to view, as described in step 3 below.)
- On the Objects tab in the Resources pane, expand the required Object node, expand the Markers node, and then select one or more markers; or
- In a 3D Perspective view pane, select one or more markers.
From the view pane tool bar, select Graph. A single Graph view pane is displayed with the default Components graph type plotting the X, Y, and Z components of each selected marker.
When you have displayed a Graph view pane, you can select additional markers to add to the Graph view pane. Each trajectory is displayed in a different color trace. To identify the color trace used for each trajectory, click the Show Legend button(or hover the mouse pointer over it) in the Graph view pane tool bar. If the trace for any additional markers is not visible, use the Fit Horizontally, Fit Vertically, or Fit Both Horizontally and Vertically buttons.
- From the Graph Type list in the Graph view pane tool bar, select another option under the Trajectories section to plot the selected marker trajectories in a different type of graph:
- Distance From Origin: Plots the distance from the capture volume origin to each selected marker. This is useful for later plotting velocity or acceleration of markers.
- Distance Between: Plots the absolute distance between two selected markers. This is useful, for example, for seeing how the distance between two markers that are assumed to have a rigid relationship, changes over time.
- Angle Between: Plots the angle between the two vectors formed by three selected markers. This is useful for seeing how the group of markers move over time.
- Trajectory Count: Plots the total number of trajectories over time visible to the Vicon cameras (if streaming Live data in real time) or processed in trial (if viewing previously captured data in a file).
- If you want to save a particular graph view (for example, specific trajectories that you have selected), save your configuration using the view pane configuration management controls.