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Benjie

Logarithmic waveform-type and limit testing.

Status: Declined

Any idea that has received less than 2 kudos within 2 years after posting will be automatically declined.

In audio industry I always use logorathmic frequency (X) axis and often also logarithmic Y-axis. Like from 20 to 20kHz but not linear as in Labview but logarithmic as in Bode-diagram.

 

Today, labview doesn't understand these. They can show them if you select that your graph-window to have logarithmic axis. But the waveform-type itself doesn't. In the waveform type you have f0, df and Y. But df is not a constant if you have log axis.

Also, the limit-testing methods doesn't understand logarithmic axis either.

 

I would appreciate it if in a future version of Labview it will allow the use of logarithmic axis.

3 Comments
RavensFan
Knight of NI

Waveforms have a t0, dt, and a Y array.  It is t because that means time, and most waveforms mean something varying in time.  But those don't have to be time, but could be anything that your X axis represents.  It is actually X0, dx, and a Y array.

 

You say df in your case is not constant.  What is your df then?  The waveform datatype is based on the X value having constant spacing no matter whether it is time, frequency, distance, ....  What you are asking for with variable spacing X values means you actually need the XY graph and not any type of waveform graph.

Benjie
Member

If you have a logarithmic axis there is no dx, since dx increase exponentially for each step.

Yes, I tried using XY-graph, but then I can't use the methods "limit testing" which require a waveform as input-parameter.

Darren
Proven Zealot
Status changed to: Declined

Any idea that has received less than 2 kudos within 2 years after posting will be automatically declined.