Adding the 'red' bullet to the start of an XY orbit plot

[Coryman]

I have a request from one of my shops to build a simple vi to monitor and plot orbits from proximity probes.  I have the orbit well defined in a simple XY graph, but can't figure how to put the 'red' bullet on the leading point of the orbit.  Is this task better tackled using a Polar Plot?

[deceased]

Easiest way I suspect will be to add a second plot to your XY graph.

Make this plot consist only a single X,Y point (of the starting position).

Then you can set the point size and plot colour of this plot to whatever you need.

0xDEAD

[billko]

You could use the plot cursor by placing it wherever on the plot you wanted to put it.

[Coryman]

I would really like it to be automatic.  I believe my best bet is to append it to the time data streams being fed into the 'Build Graph' vi.  But this feed is continuous.  How do I put it at the beginning of the orbit?  It sounds like it might be best to build the array from a set of points, plot it and then repeat.  Again, I am not real saavy on building arrays, let alone adding just one point and that point I want to be a red dot.

[RamonG · Accepted solution]

Example of deceased's post:

[Coryman]

Thank You!!!!!  I now have a 'red' open square riding my data orbit at the key phasor position!  Now I just have to trim down the number of points in my filtered orbit.  It overpowers the small red square.  But I can handle that!

Cheers,

Ron

[Coryman]

I guess I spoke too soon.  The 'red' open square is on the end of the orbit, not the beginning, or the trigger point.  If cut down the samples in my orbit, e the square follows the end of the trace and doesn't stay on the fixed end of the orbit.  In other words, as I cut down on the samples, the red square follows the end point of the truncated orbit.  It should stay with the lead point, no?

[RamonG · Accepted solution]

My apologies, I misread.

Not setting the indexes will give you the first coordinate. Changing the order of the graphs should leave the bullet on top.

[Coryman]

YES!!!!  Thanks again!