How to normalize the data?

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Ara
Ara on 14 Mar 2013
Commented: Ara on 14 Jun 2014
Hi Everybody,
I have to normalize this data to 0 to have signal intensity in dB. I do not know how to write the code and then plot it.Could you please help me?
L1 CNo (dB-Hz)
55.15
45.59
45
45.33
53.91
41.5
51.1
47.1
48.04
56
46.68
45.31
45.54
54.67
42.23
51.28
48.23
48.01
55.76
  2 Comments
Sifiso
Sifiso on 13 Jun 2014
Edited: Sifiso on 13 Jun 2014
Why don't you first normalize the data as is in absolute units, such that your maximum value from your data will now have maximum value = 1. And the rest will be a fraction of 1. i.e Norm_abs = abs( L1 CNo)./max(abs(L1 CNo))
Then you may convert this to dB. 10*log (Norm_abs). All will now be relative to 0 dB and lie below 0dB.
Ara
Ara on 14 Jun 2014
Thank you very much for your useful suggestion.

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Answers (1)

Honglei Chen
Honglei Chen on 14 Mar 2013
Edited: Honglei Chen on 14 Mar 2013
If I understand you correctly, say your data is x, you basically want
10*log10(x/max(x))
However, it also looks like your data is already in dB since in the first row it says dB-Hz. In this case, if you want to normalize to 0 dB, you should do
x-max(x)
  2 Comments
Ara
Ara on 14 Mar 2013
Edited: Ara on 14 Mar 2013
Thanks for your help. Here is the link that show the plot I wish. http://www.sendspace.com/file/78hxof Your code is good but still not set to zero. I tried
x-max(x)
but still not set to zero, actually I want to see the fluctuation by normalize "x" to 0.
Jan
Jan on 14 Mar 2013
What should be set to zero?

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