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How to create a amplitude against freq graph?

Hi, Iam new in labview. I measured amplitude from my DMM connected through GPIB. I also measured is freq result. How can i plot a graph of amplitude against freq plot?(something like a freq response plot). I do not know how to change the the x-axis of the waveform provided in labview into freq. Thank You.
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Message 1 of 24
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Hi

find attached a small vi, where "old" Data are shown
in XY-Graph versus frequency. The old style graph
is made in double logarithmic way.

You only need to create an array of frequency and Amplitude-Data, then feed the graph -that's it.

Hope this helps.

regards
Werner
Message 2 of 24
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> Hi, Iam new in labview. I measured amplitude from my DMM connected
> through GPIB. I also measured is freq result. How can i plot a graph
> of amplitude against freq plot?(something like a freq response plot).
> I do not know how to change the the x-axis of the waveform provided in
> labview into freq. Thank You.

If you are plotting an array of amplitudes sampled at various
frequencies to a waveform graph, you are pretty close. The scale will
default to being labeled by index -- first amplitude plotted against
zero, second against one, etc. You can programmatically or
interactively add a linear transform from index to displayed number. In
otherwords, you define an M and B to define what zero maps to, what one
maps to, etc. And you can also use t
he labeling tool to change the
scale label to read frequency or whatever you like.

If your frequencies aren't in a linear progression, or if you just think
it is simpler, use an XY graph instead, and put the frequency with each
amplitude in a cluster. Make an array of these XY paired clusters.
Then change the scale label.

Greg McKaskle
Message 3 of 24
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i have an array of frequencies and amplitudes . i need these values to be displayed on x-axis frequency values and y axis amplitude values . one fixed default plot should be continuously visible in this graph and then i wish to mark few user defined points in the same graph, save them and then take a print out of the graph.

Kindly help this is regarding my master of engineering project where i am trying to biuld an audiometer (for testing hearing sensitivity) and i am going to interface labview with ardiuno micrcontroller and my hardware devices.

so kindly help.

thank you.

vanashree.

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Message 4 of 24
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Use an XY graph.  With your data in individual 1D arrays (1 for X and 1 for Y having the same number of elements) create a cluster using the Bundle operation.

Wiring this cluster to a XY graph will create a plot.  You can add additional plots by creating an Array of Clusters.  Each Array element will be a XY cluster which represents one plot on the graph.

 

So, to you your fixed data, place it in element zero of an array.  Any additional data can be added or removed from the array as you see fit (adding multiple plots or replacing them).

Message 5 of 24
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hey...

m really glad to recieve this..thanks for ur quick reply..i will definitely try this and let u know..thanku..

🙂

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Message 6 of 24
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hey..

i wish to place two separate constant graphs (with x axis frequency array and y axis intensity array) in a single x-y graph.then i wish to plot in running v.i. third graph where x axis and y axis values will be user defined.i am new in labview kindly elaborate your explanation.

i have already placed one fixed plot in a x-y graph.kindly go through the attachment.kindly help.

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Message 7 of 24
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i have used bundle function and made the fixed plot but i am not able to place more than one plot on a single graph using array of cluster as discussed.kindly elaborate..kindly help.

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Message 8 of 24
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Here's a quick little vi to demonstrate.  The inner for loop creates an XY pair, the outer for loop bundles the results and places into an array.  The result is a 1D array of Clusters (2 elements of 1D arrays: XY).

Message 9 of 24
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sad...i have labview 7.1 so..m not able to view this as its in labview 9

can u save me??i m stuck......

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Message 10 of 24
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