scaling

[gareth1983]

Hi all,

I'm trying to work out some programs with reference to http://zone.ni.com/devzone/cda/tut/p/id/4541, as recommended for FFT analysis.

While trying to draw out figure 8, to display a double sided output format, I realise I couldn't linked the paths to the waveform graphs.

The error is due to some sort of different arrays, which I had changed. Can someone explain to me where had gone wrong again?

Message Edited by gareth1983 on 03-16-2009 06:53 PM

[gareth1983]

I'd corrected the real part, but when I applied the same method to the imaginery part, it's still not working.

[Coq_Rouge]

I think you should stick with the Single-Sided Output. I think showing frequency's above the Nyquist frequency in a spectrum plot is wrong. The information value is zero.

http://en.wikipedia.org/wiki/Nyquist_frequency

[STTLLER]

Hi friends

I am Joseph from London. I am trying to find the answer of your question so can you send more detail of the above question.

Joseph

[Coq_Rouge]

Just to explain your problem. I am doing it because the help is pretty useless on this topic. You have a problem because your cluster order is wrong. To use a waveform graph you should built your cluster this way

1. Element=X0

2. Element=delta x(interval between elements on x axis)

3. Element=data set (data array)

Now you can place a waveform graph on your block diagram and wire it to the cluster output

More here .....\examples\general\graphs\gengraph.llb\Waveform Graph.vi

[gareth1983]

thanks for the guidelines. I'm now able to connect the different outputs to a single graph for the above example.

I'm working on something else right now but I encountered a different situation this time round. I'm supposed to connect 2 different outputs with 1 output being signal before DTFT, and another being after DTFT.

I'd tried changing color scheme, to make sure they don't overlap. I even had tried having 2 individual graphs to show the 2 types of output to prove that the waveform is working. However when I want to connect them to the same graph, I can only see 1 waveform.

You may want to take a look at the attached files.

[RavensFan]

The screenshots of the front panel are nice, but can't help us figure out what is wrong.  Perhaps you could attach the latest version of your VI?

[gareth1983]

Hi,

attached is my latest version of the vi which I had done. now i cannot connect the output (at the extreme right) to the waveform chart labelled Real as well.

Message Edited by gareth1983 on 03-20-2009 11:54 AM

[RavensFan]

Exactly what are you trying to do over there?  You have two very odd pieces of code.

1.  You take an array, split it at some index, then put it back together.  What comes out is identical to what you put in.

2.  What are you bundling into a cluster?  You have an array, but you are also bundling in an integer 1 and a double numeric value.   What are the 1 and the double supposed to mean?

Are you actually trying to build a waveform?  If so, you should be using the Build Waveform function on the waveform palette.

[RavensFan]

I took another look at our VI and saw that your graph is actually an odd cluster of a double, integer, and double array (in that order).  How did you create that?  And why?

The reason your bundle cluster won't connect with it is that you bundled your cluster in the opposite order (array, integer, then double).

Reverse the order of your bundle cluster then you'll be able to connect the wire to the Real "waveform graph".  But that still doesn't explain why that graph is an odd cluster.