subdivision in scale XY graph

[Alain_S]

Hi there,

I wonder why LV 8.6 (yes, I still use that version) sometimes return only the extremes and center points (-5, 0 and +5) and sometimes all integers in between on the X scale. See attached picture.

What property should I change to always have all integers on the X scale?

Unfortunately I can't post the vi since the graph is made of about 280.000 data points.

Strangest of all when I decimate the data set (use only 1 data point out of 9), then all integers appear in the X-axis ?!!?

Thanks for any reaction.

[GerdW]

Hi Alain,

your graph is too busy to draw all your data points so it can't afford to draw those integers on the axis...

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I can't post the vi since the graph is made of about 280.000 data points.

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What's the reason to show ~300k samples on a graph that is only ~250 pixels wide?

Is there any good explanation why you represent ~1000 samples by just one pixel?

Decimate your data to a reasonable array size: 500 samples should be more than enough for your graph. As you already noted everything else will work then 😄

[DFGray]

I certainly agree with GerdW that you should decimate your data for display, but I suspect there is something else going on in your code.  Normally, you can put a million points or more in a graph with no real issues, although your memory usage and time-to-display will suffer.  You can post your code if you right click the graph of the VI and select Data Operations»Clear Graph.  This will remove all data from the graph and should make your VI small enough to post.  If that does not work, put it in a ZIP file and post that (VIs compress well).

Note that decimation for display for an XY graph is quite a bit more complicated that decimation for display for a time graph or chart.  We can get into that if we need to.