Turn around a log graph

[Christie]

Hello all,

I need a strange graph.  It has to be logarithmic, but I need the time axis markers to be spaced so that the first values are denser than the last values.  In other words, I need the same physical space between 0 and 100, and between 100 and 110.  Is there an easy way to do this?

Thanks

Christie

[Paul Champion]

I can't make it look pretty, but I can get the functionality, I think.

I used a regular x-y graph with the x-axis set to logarithmic scale. I then set the XScale.Multiplier and XScale.Offset to -1 and 111.1111111... (1000 / 9, which is the upper limit of your scale), respectively. The big issue with this is you must compensate all of your x-values for this by reversing the calculation (i.e. subtracting 1000/9 and negating) before feeding it to the graph. Also, the graph tends to become ugly at values closer to zero.

Does anyone else have an easier (prettier) solution?

[Christie]

Hi Paul,

Thanks for the good idea.  I haven't got Labview 8, but from your description I created a LV7 VI that formats a graph.  It does the trick.  Attached is the VI for whoever wants to do the same.  Just remember to set autoscale to false.

Thanks

Christie

[Christie]

Hi all.

I have come across a problem with this inverted log graph.  I configure the graph in this order: Multiplier, Maximum and then Flipped.  I found that the moment the Flipped flag is set, Labview changes the Maximum.  If I first set the Flipped flag and then change the Maximum, the Flipped flag is changed.  Why does Labview change the Maximum value and how can I avoid this?

Thanks

Christie

[AdnanZ]

Hi Christie,

I hope you are doing well today! I am not able to replicate the behavior over here. The function of the Flipped property is that If TRUE, it reverses the positions of the minimum and maximum values on the scale. So, LabVIEW changes the value of maximum to minimum. I am not sure why Flipped switches to False if you change the value of maximum. Can you attach a simple program that has a graph and a property node and can replicate the behavior you are seeing? Have a great day!

[Christie]

Hi there.

I have solved the problem.  If I add 1 to Offset, Maximum is correct.  I forgot that the offset affects the maximum.  I have attached a little example that shows how the Flipped flag is changed automatically.

Cheers

Christie

[AdnanZ]

Christie,

I still don't see the Flipped property being changed to True. This is after I removed the second from last Flipped property. The indicator remains false. Were you trying to communicate something else?

[Christie]

That is odd indeed.  When I run the VI as it is (I downloaded it again), the Flipped indicator goes true.  Could this be a change between Labview versions perhaps?

Christie