DPlot

I have an application that draws a bubble plot in real time, ie single values are plotted as they are generated by the application using the following commands:

ret = DPlot_AddData(graph_number, %DATA_XYXY, 1, 1, x, y)
ret = DPlot_AddData(graph_number, %DATA_XYXY, 1, 2, x, z)

This works fine, except that it is incredibly slow. The reason seems to be that adding each new point forces the whole graph to be re-drawn (with a lot of flickering).

When setting up the graph, I made sure that it was manually scaled with the ret = DPlot_command(graph_number,"[ManualScale(..etc...)]" command. This presumably stays active during later data additions. I have also tried:

ret = DPlot_command(graph_number, "[MenuUpdates(0)]")

but no effect. Is there any way to stop the re-drawing process when adding data for this graph type, or am I doing something wrong?

Thanks

Peter

See the notes at the bottom of
http://www.dplot.com/lib/index.htm?dplot_adddata.htm

In particular, you'll want to turn off antialiasing ([GeneralOptions(32,0)]) and you might also want to use DeferMinMaxCheck.

If it is still slow then my best suggestion is to accumulate points and send 100 or so at a time.

PS: Whether using ManualScale or not, you shouldn't be seeing a lot of flickering. There should never be a blank screen between plot updates, unless you're using a fairly old version. It should appear that your symbols are being drawn directly on the existing plot, w/o erasing the display between updates. If that isn't what you're seeing, you likely need an update. If you are already using a recent version then I've overlooked something. In that case please let me know what version you're using and what development environment your program is using.

I'm using version 2.2.9.3 of DPlot Jnr. I am calling the DLL from PowerBasic console compiler in Windows NT SP3.

The plotted points seem to disappear and re-appear every time a new point is added which looks as though they are all being replotted.

I've just written a subroutine to spool points into 100s or 1000s before plotting which completely solves the problem.

Just a note, the declaration of the DPlot_Disconnect function was missing in the Powerbasic INC file (and in the equivalent files for some of the other program languages. Easily fixed by adding:
Thanks for your help

Peter

Thanks for the PB information.

I'm glad you got this working to your satisfaction, but: the plot should not be redrawn at every call unless the plot extents are changed by the addition of a point. That's the most likely cause. Another is that you're calling ViewRedraw after every point, but I'd have thought you'd have noticed that.