Plot data

[celynn]

Hi can anyone advise me on how to plot my data back on to the graph.

Say i perform some signals analysis like power spectrum to my time signals and i am able to plot out the power spectrum of each signals easily and after doing some maths (like multiple and divde) to the calculated spectrum, i am able to obtain the values but how do i plot these values back against the frequency?    

[alkazaa]

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@celynn wrote:

Hi can anyone advise me on how to plot my data back on to the graph.

Say i perform some signals analysis like power spectrum to my time signals and i am able to plot out the power spectrum of each signals easily and after doing some maths (like multiple and divde) to the calculated spectrum, i am able to obtain the values but how do i plot these values back against the frequency?    

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It is not clear to me what you mean by 'plot these values back against the frequency'. Could you provide some more information, or some VI showing what you attempt? (Please post for LV version 7.0 or post a screen print)

-Franz

[celynn]

Say some maths are done in the loop like multiple or divide. i was able to get the values in the array but not able to plot the values out.

Any idea why?

[alkazaa]

The example shown in the bitmap cannot work: you will not be able to connect any input coming into the left side of the FOR loop to the output on the righ side, since 'Array' is a control. Make 'Array' an indicator and it should work.

You can try to downconvert your VI for posting it by using from the menu 'File->Save with Options->Save for previous' and then select Labview 7.0

-Franz

[celynn]

After i change my "array" to indicator the plot does not work either. It looks to me that i need to plot my array values (y-axis) against the frequency( x-axis). i have my array values but no idea how to plot them against its frequency(y-axis). As you can see that the psd magnitude values are at its own frequency already. What i did was to do some maths in the loop and plot the output.

Do you get what i mean? 

[alkazaa]

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@celynn wrote:

After i change my "array" to indicator the plot does not work either. It looks to me that i need to plot my array values (y-axis) against the frequency( x-axis). i have my array values but no idea how to plot them against its frequency(y-axis). As you can see that the psd magnitude values are at its own frequency already. What i did was to do some maths in the loop and plot the output.

Do you get what i mean? 

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Sorry, I was a bit stupid the first time...
You should use 'bundle by name' (found in the clusters function pallette) to get that start frequency f0 and the freqeuncy step df information. See attached picture.


-Franz

[celynn]

Many Thanks.

Can you advise me further on how to change the y-axis from decimal (0.4) to 400?

If i change the SI notation i will get 400m ?

[DFGray]

Use a graph property node and set the scaling on the axis.  Make sure you update your label accordingly.  You can then use SI units.