Why I am getting nans when calculating the PSD for a sequence of numbers?!!
13 ビュー (過去 30 日間)
古いコメントを表示
Hey all,
I have a sequence of data saved in a column vector. I know that Fs = 400 Hz for the data when it was collected in time domain. I want to see the frequency component and calculate the power spectrum density. I used [Pxx,w] = pwelch(x) and all hat i'm getting is Nans in complex and real format!! x is my column vector. Where did I go wrong?!
0 件のコメント
回答 (1 件)
Wayne King
2012 年 11 月 26 日
編集済み: Wayne King
2012 年 11 月 26 日
Is there a NaN in your data?
If you have a NaN in your data, that will create the output you describe. For example:
x = randn(1000,1);
x(100) = NaN;
[Pxx,W] = pwelch(x);
You can check for NaNs with isnan()
3 件のコメント
Wayne King
2012 年 11 月 26 日
Yes you should, the question is what is a meaningful thing to do because the PSD estimate assumes that the data is uniformly sampled. If you just remove the NaNs that is no longer the case.
参考
カテゴリ
Help Center および File Exchange で Parametric Spectral Estimation についてさらに検索
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!