![]() If you don't specify fs, the frequency range is [0, 2 ).If you specify fs as the empty vector,, the frequency range is [0,1).This is the default for determining the frequency range for complex-valued x. 'whole': Compute the pseudospectrum over the frequency range [0,fs).Specifies the range of frequency values to include in f or w. The arguments nwin and noverlap are ignored when you include the string ' corr ' in the syntax. See the Table , Eigenvector Length Depending on Input Data and Syntax below for related information on this syntax. Length(nwin) must be the same as the column length of x, and noverlap is not used. Comments on the resulting windowed segments are described in the following table. The segmentation of the data depends on nwin, noverlap, and the form of x. With this syntax, the input data x is segmented and windowed before the matrix used to estimate the correlation matrix eigenvalues is formulated. The default value for nwin is 2*p(1) and noverlap is nwin-1. Use the scalar integer noverlap in conjunction with nwin to specify the number of input sample points by which successive windows overlap. For this syntax x must be a square matrix, and all of its eigenvalues must be nonnegative.Īllows you to specify nwin, a scalar integer indicating a rectangular window length, or a real-valued vector specifying window coefficients. S and Frequency Vector Characteristics with fs Specifiedįorces the input argument x to be interpreted as a correlation matrix rather than matrix of signal data. The following table indicates the frequency range for f for this syntax. The length of S (and f) is the same as in the Table , S and Frequency Vector Characteristics above. The frequency range for f depends on nfft, fs, and the values of the input x. If you specify fs with the empty vector, the sampling frequency defaults to 1 Hz. You supply the sampling frequency fs in Hz. Returns the pseudospectrum in the vector S evaluated at the corresponding vector of frequencies f (in Hz). The following table indicates the length of S and w, and the frequency range for w for this syntax. The default value for nfft (entered as an empty vector ) is 256. Specifies the length of the FFT used to estimate the pseudospectrum with the integer nfft. Range of the Corresponding Normalized Frequencies S Characteristics for an FFT Length of 256 (Default) The following table indicates the length of S (and w) and the range of the corresponding normalized frequencies for this syntax. In general, the length of the FFT and the values of the input x determine the length of the computed S and the range of the corresponding normalized frequencies. The extra threshold parameter in the second entry in p provides you more flexibility and control in assigning the noise and signal subspaces. In this case, p(1) specifies the maximum dimension of the signal subspace. Eigenvalues below the threshold min *p(2) are assigned to the noise subspace. In this case, p(2), the second element of p, represents a threshold that is multiplied by min, the smallest estimated eigenvalue of the signal's correlation matrix. ![]() In this case, the signal subspace dimension is p. ![]() ![]() You can specify the second input argument p as either: You can use the output of corrmtx to generate such an array x. A rectangular array for which each row of x represents a separate observation of the signal (for example, each row is one output of an array of sensors, as in array processing), such that x'*x is an estimate of the correlation matrix.A row or column vector representing one observation of the signal.The pseudospectrum is calculated using estimates of the eigenvectors of a correlation matrix associated with the input data x, where x is specified as either: Implements the eigenvector spectral estimation method and returns S, the pseudospectrum estimate of the input signal x, and w, a vector of normalized frequencies (in rad/sample) at which the pseudospectrum is evaluated. Peig (Signal Processing Toolbox) Signal Processing ToolboxĮstimate the pseudospectrum using the eigenvector method
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