Cannot draw logarithmic graph in Plot Multi-XY vi

[jmburns]

Hello All,

I'm trying to use the Plot Multi-XY vi in the picture controls to dynamically draw an X-Y grid on a picture control.  I need the grid to be logarithmically scaled, but when I check the "x log?" and "y log" booleans in the cartesian axis attributes to True, nothing at all shows up in the picture.  If I un-check those options, I get a nice linear grid.  Any help would be greatly appreciated!

Thanks,
Jason

[RavensFan]

Can you attach a VI or screenshot so we can see what you are talking about?

[jmburns]

Hi Ravens Fan,

Here's the VI (taken from an NI Example with just the Cartesian Axis Attributes added and the x and y logs turned to true.  If you switch them to false you get a nice graph, but when set to true nothing shows up at all.

Thanks,
Jason

[RavensFan]

I dug down deep to see where the log axis boolean came into play.  There are mulitple levels of  hierarchy that makes it hard to understand exactly what is going on.

But I think the problem is related to this.  The plots that are generated are sine and cosine based, which means they go to the negative side of the axis which are things you can't plot on a log scale.

[jmburns]

Wow.  You're right.  Thanks for getting back to me so quickly, and sorry for wasting your time on this one!

[RavensFan]

No problem.  Answering that question helped wake up my mind this morning.

[jmburns]

Apparently mine hasn't quite woken up yet.  Time for more coffee - hopefully that will help.  Thanks again!