Property Time-series Graph

The property time-series graph widget displays a sequence of values for a specific thing property as it has changed over time.


Field	Description
Property time-series graph	The name of the widget, shown at the top of the widget.
Thing key	The thing key this widget should respond to. If left blank, the widget will inherit the thing key from the dashboard.
Thing property (mandatory)	The property of the thing to be shown by the widget.
Thing alarm	The key of the alarm that to overlay on the graph. At the point in time when the thing changes alarm state, a vertical line with the alarm state's color will be drawn on the graph.
Graph type	Specifies how the property graph should be presented. Line will show the property as straight lines connecting points. Spline will show the property as a curved line connecting points. Step will show the property as a series of lines forming steps between points. Area will show the property as a line with a shaded portion of the graph. Area-spline will show the property as a curved line with a shaded portion of the graph. Area-step will show the property as a series of lines forming steps between points with a shaded portion of the graph.
Show points	If the points on the graph should have dots on the specific property points on the graph.
Show average	If the graph should show a line for the average property value.
Y axis max	The upper bound of values that should be shown on the graph. The property may have values that exceed this boundary and those values will not be visible on the graph.
Y axis min	The lower bound of values that should be shown on the graph. The property may have values that are lower than this boundary and will not be visible on the graph.
Unit	The unit of the property. Displayed in the upper right hand corner of the widget.
Line/area color	The color of the line/area representing the property value.
Show legend	If a legend should be displayed at the bottom of the pie chart. Clicking the color in the legend will toggle if that series is displayed in the graph.
Show border	If the widget should have a border around it.

If you are displaying the legend, moving the mouse pointer over the legend highlights the property on the graph. Clicking the color in the legend switches the line on and off in the chart.
Moving the mouse pointer over a point on the line displays the date-time, color, property, and value of that point.
Moving the mouse pointer over an alarm vertical line displays the date-time, color, and alarm state.

Data Bracketing Algorithm

Graph widgets are subject to a data bracketing algorithm. This is done to alleviate excessive white space in the graph as a result of data gaps between the start of the time series and the first data point and between the last data point and the end of the time series.

The average time interval is calculated for the number of points in the date range and then a 1.5 multiplier is applied to define an acceptable margin.
If the first reported point occurs later than the graph's start date by an amount greater than the acceptable margin, an extra data point with the same first value will be inserted at the start of the time-series.
If the last reported point occurs earlier than the graph's end date by an amount greater than the acceptable margin, an extra data point with the same last value will be inserted at the end of the time-series.

These extra data points are only inserted for the purpose of the display. On refresh of the graph, these extra data points are not retained. The data bracketing algorithm is applied again on the new time-series data set to determine if extra data points are required.