Help: Cannot filter a text based graph

[monkaren]

Hello everyone,

I have a text file which I am using to generate a graph and it works well. However, when I try to wire this array to a Build Waveform it shows a broken wire (as shown in the image below).

I added the Build Waveform because it didn't let me filter the signal directly from the array. I found that solution here http://goo.gl/wjacvO

How could I filter my signal using this function? Thanks in advance.

[Dennis_Knutson]

You can't wire a 2D array to the Build Waveform or to the filter function. You need to use the Index Array to get a specific row.

[altenbach]

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@monkaren wrote:

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And please don't copy my code in the upper right. 😄

(If you don't understand what I mean, look here.) 😄

[monkaren]

I tried that, but then the error Analysis:  The following conditions must be met:  0 < f_low <= f_high <= fs/2. appears and it's not filtering anything. I already added t and dt, so it is supossed to be working well, right?

[monkaren]

guilty! haha I'm a total beginner here, please bear with me. Great cartoons!

[James.M]

You code doesn't have a t0 value written.

Your error has something to do with your filter settings. Right-click the filter to see what the settings are.

Supply us with some data so we can help more. Add another waveform graph to the output of the Filter express VI so you can see the filtered signal.

[Dennis_Knutson]

You have not attached your data file so it's impossible to say what might be wrong. Instead of the first row, you may need to index a specific column.

[monkaren]

I'm sending both the .vi and the text file I'm using.

Thanks guys.

[James.M · Accepted solution]

FYI, you should set default values to where you have them working when you're sharing code. Your delimiter is "\s" and I have no idea what your dt value is.

You need to play with your cutoff filter to match your data rate. It was set to 100.

I made it work with 0.1 dt and 0.5 cutoff:

[monkaren]

It works nicely! Thank you for your help James.

All I have to do now is to figure out why it works under these parameters.

Best regards.