We come back to the PmaTrendGroup object in the editor of Pma objects. Any PmaTrendGroup object can read and evaluate the data either from databases created by the PROMOTIC system or from databases created by any other system, by the 3rd party in the "read only" mode. This possibility can be configured by setting the option PmaTrendGroup > Trend > Read only (new records cannot be written).
The PmgTrendViewer object can be used even as a common stand-alone viewer of 2-dimensional function f(x) (i.e. there needn't be presented only the process of the time on the x-axis).
This view type can be set by the PmgTrendViewer.TimeType property, then all methods of the tvPoints object take real values instead of time parameters and they return real values instead of time values, for example the tvPoints.AddPoints method in the vTimes parameter takes the real value array instead of the time array.
By the PmgTrendViewer object it is possible, by clicking the mouse, to define a trend process (i.e. add new points or delete existing ones) or a graph of 2-dimensional function f(x) (according to setting the PmgTrendViewer.TimeType property), namely by definition in the script in the PmgTrendViewer.onMouseArea event. By the methods tvPoints.AddPoints, tvPoints.RemovePoints it is possible to place a new point on the position where the mouse was clicked, or to remove the point(s)from it, see the example in the onMouseArea event.