LabVIEW
Engine Data Acquisition System
Could be? Something to bear in mind is that if the pressure is not a single-valued function of angle, then you won't get a very nice graph - eventually it will probably just be a big block of white (if they don't share some common factor in terms of repeating).
You'll also note there are lines from the "last" point at ~360deg (although yours looks earlier?) to the next "first" point at ~0deg - if you want to remove these joining lines you can append "NaN" to both arrays each time angle has a negative slope (e.g. from 360 -> 0), where normally it's positive (e.g. 10 -> 10.5 -> 11). You could also create a new plot each time this happened, but that will be really slow if you have more than a few repetitions.
If your graph with real input (i.e. engine) nicely lines up each rotation, you can choose to do nothing, or perhaps plot an average value per angle. That would be something like the splitting to new plots, but not actually plotting - instead, averaging over all 0-360 deg segments at each angle (you might need to bin to each 1 deg or similar given currently you're using the time as the clock, not the angle) and plotting that.
Fantastic, looks very nice.
@JerryD4299 wrote:
Thanks for your help man. I finally got the graph I was longing for.
Just a question here. Whenever my encoder finishes 360 degrees, it resets back to zero, and on my graph I see a line going back. How can I tell lab-view to reset after 720 degrees instead of 360 and also how to remove that return line if possible? I'm uploading my VI and the image.
TIA
See the previous post re breaking the line. To make the graph 720 degrees wide, add 360 degrees the first time you detect negative slope, and reset the second time.
Consider a shift register with boolean (needs reset) or just checking =360, and a SR containing the degrees to add (0 or 360) depending on where in the 720 degrees you are.
More detail can be found in my previous post for most of this.
Here's a possible pointer showing the addition of NaN elements for a set of data every 720 elements. You can see the use of two Shift Registers to track the relative additions and so on (the data source is between 0 and 359).
This might not directly solve your problem but should be close enough that you can use this if you wanted to remove the lines (as I previously explained) between "last" and "first" points whilst extending, in this case, to 720 degrees plotting.
It's worth noting that by using the Select node in the True case with an array of values, the True being a one element array containing NaN (not a number) and the false being empty, that I can avoid modifying the data in the False case. If I used a scalar value, with NaN the output would be the same, but there's no "empty" scalar value.
