Introduction to Graphs

Source file: graphs.htm

A graph in Sentry plots data of a specific type over the total scanning time interval. The screenshot below shows the elements of a zone-based graph; in this case, Displacement:

• The graph type selector is used to choose the type of graph to display. A single graph view can only display one type of data at a time.

• Plot lines graph the data for each selected zone. Each plot line has the colour of its associated zone. Some graph types, such as Inverse Velocity, plot data as points rather than lines.

• Grid lines provide a sense of the scale of data in each dimension. The spacing between grid lines changes dynamically whenever the graph view window is scaled. Each grid line is labelled according to its range and units:

  • Time axis labels: Vertical grid lines are labelled with the time they represent along the bottom of the graph, and with a minor day label at the top of the graph wherever a new day starts.

  • Vertical axis labels: Horizontal grid lines are labelled with the value of the line at that point on the vertical axis and a unit appropriate to the graph type.

• The graph view date displays the date of the left-most point of the graph.

• The time slider is a vertical red line that indicates the time of the current scan. This corresponds to the scan displayed in the scene viewer. Drag the time slider to change the current scan to a new time.

• The measurement base indicator is a green line that shows the position in time of the measurement base (see Configuring).

Graphs in Sentry are classified as either zone-based graphs or general graphs.