Re: Redrawing XY and transparent Graphs (long)
wayne galbraith [EMAIL PROTECTED] wrote (in part): I'm guessing that, that is what most people are after and as such would require a buffer of some description to be kept. It is a bit of a pity NI couldn't have written this as I'm sure their s.ware engineers could write it much more efficiently than the rest of us. Basically - shove the data in one end with a buffer size limit and then allow you to plot any point against any other appending data only as you go. Then if the X-axis on the plot has altered then redraw the whole plot. This I'm guessing is what most of us have implemented on our own - just not as efficiently as NI may have written it. wayne === I use the XY graph regularly to display time stamped data where the timestamps do not occur at regular intervals. I have developed a few subVIs to support this. There are examples of this approach on the Process Automation Corporation website. If you want to download an example of this go to: http://www.processauto.com/Downloads.htm and look for the following text: Download a LabVIEW v6.0.2 program (133 Kbytes *.exe file) that shows how to create a plot that changes colors when high and low alarm limits are exceeded. It also demonstrates how time stamped data [i.e. (y,t) points] can be buffered and displayed on LabVIEW XY graphs. Lewis Drake Process Automation Corporation Belle Mead, NJ 908 359-1011 www.processauto.com
Re: Redrawing XY and transparent Graphs (long)
wayne galbraith wrote: This is something that we have all had to put up with for many years and I don't see NI solving it in the future. Surely the most popular plotting technique is with an XY graph as we all don't simply plot against time. I am guessing there is a fundamental problem with only adding one extra point at a time - although maybe Greg Mc will let us in on the secret. Since the Measurement Studio ActiveX graph control has YDataAppend and XYDataAppend on a per-plot and per-graph basis, there doesn't seem a fundamental reason. And since it looks very like the LV graph, you can use it as a drop-in replacement on the panel, though of course it's not as easy in the code. -- Dr. Craig Graham, Software Engineer Advanced Analysis and Integration Limited, UK. http://www.aail.co.uk/
Re: Redrawing XY and transparent Graphs (long)
Craig The only problem that I could see here is changing your X axis during displaying of data. Does the Active X control keep any kind of buffer?? I'm guessing that, that is what most people are after and as such would require a buffer of some description to be kept. It is a bit of a pity NI couldn't have written this as I'm sure their s.ware engineers could write it much more efficiently than the rest of us. Basically - shove the data in one end with a buffer size limit and then allow you to plot any point against any other appending data only as you go. Then if the X-axis on the plot has altered then redraw the whole plot. This I'm guessing is what most of us have implemented on our own - just not as efficiently as NI may have written it. wayne At 08:47 AM 12/05/2004 +0100, you wrote: wayne galbraith wrote: This is something that we have all had to put up with for many years and I don't see NI solving it in the future. Surely the most popular plotting technique is with an XY graph as we all don't simply plot against time. I am guessing there is a fundamental problem with only adding one extra point at a time - although maybe Greg Mc will let us in on the secret. Since the Measurement Studio ActiveX graph control has YDataAppend and XYDataAppend on a per-plot and per-graph basis, there doesn't seem a fundamental reason. And since it looks very like the LV graph, you can use it as a drop-in replacement on the panel, though of course it's not as easy in the code. -- Dr. Craig Graham, Software Engineer Advanced Analysis and Integration Limited, UK. http://www.aail.co.uk/ -- Wayne Galbraith School of Civil and Resource Engineering The University of Western Australia 35 Stirling Highway Crawley 6009 Tel - (08) 6488 3788 email - [EMAIL PROTECTED] www.civil.uwa.edu.au/nata --
Re: Redrawing XY and transparent Graphs (long)
wayne galbraith wrote: Craig The only problem that I could see here is changing your X axis during displaying of data. Does the Active X control keep any kind of buffer?? Yes, it definitely buffers because one of my (VB) apps pans, zooms and scrolls without reloading the data. The X axis can be set manually. Obviously changing the X axis causes a redraw. -- Dr. Craig Graham, Software Engineer Advanced Analysis and Integration Limited, UK. http://www.aail.co.uk/
