09-28-2009 12:46 PM
Hello-
I currently have a VI that reads in information through the DAQ Assistant into two waveform charts (load vs. time and displacement vs. time). I would like to be able to take this information and plot another chart (load vs. displacement). I have converted the dynamic data sets from the waveform charts into two arrays (load and displacement), and then bundled them into an array of clusters. I have tried adding a waveform chart to the array of clusters, however it does not appear to be plot. (This is all located in a loop so that it should constantly update as the test is being performed.)
I would appeciate any help you may have. Please let me know if you have any questions.
Thank you for your time.
Solved! Go to Solution.
09-28-2009 01:07 PM
09-28-2009 01:13 PM
A chart is just wrong if you want to plot one array against another. That is what an XY Graph is for. Just take your existing arrays and bundle them together. If you turn on Context Help (and it really should be on all of the time) on the block diagram and move your mouse over the graph, it shows you exactly how to wire the data. Since a graph has no history, you will have to implement that if necessary. There's an example called XY chart or simply search the board. Numerous examples that use a couple of shift registers. The Express XY Graph can be used as well.
Don't know why you want this in a separate loop. Placing it next to your chart writes would make as much sense.
09-28-2009 01:20 PM
and just for your reference to use the chart you need to have a cluster of dbl not and array of cluster of dbl.... but dennis is correct if you want to plot one array against another
here is an example of xy-graph.
09-28-2009 01:23 PM
Thank you for your help.
Would you please direct me to the "XY Graph" function? When I search the functions palette, all I can find is "Plot XY" and "Plot Multi-XY." (Both are picture plots.)
09-28-2009 01:28 PM
Be sure you're using the correct terms. In LabVIEW, a CHART is different from a GRAPH.
A CHART has its own history buffer and can construct a plot (or several) from feeding it one point (or several) at a time.
A GRAPH has no such history; when you feed it new data, the old data is forgotten.
There is no such thing as an X-Y chart.
The X-Y graph is polymorphic; meaning it can accept different kinds of data.
For details; use the EXAMPLE FINDER to open FUNDAMENTALS - GRAPHS AND CHARTS - XY GRAPH.vi
There you can see four ways to connect data to an X-Y graph.
Blog for (mostly LabVIEW) programmers: Tips And Tricks
09-28-2009 01:36 PM
09-28-2009 01:43 PM
Thank you all for your help. I looked at the example posted in this thread (as well as the ones on the forum and in the Labview Examples) however, I do not appear to have access to "XY Graph." Is there another way of approaching this problem?
09-28-2009 01:44 PM
Blog for (mostly LabVIEW) programmers: Tips And Tricks
09-28-2009 01:47 PM
Functions palette?
It's on the controls palette. Right next to the chart, and waveform graph.