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# rooteig() - Signal Processing

### Syntax

### Example

### Output / Return Value

### Limitations

### Alternatives / See Also

### Reference

[w,pow] = rooteig(x,p) estimates the frequency content in the time samples of a signal x, and returns w, a vector of frequencies in rad/sample, and the corresponding signal power in the vector pow in units of power, such as volts^2. The input signal x is specified either as:A row or column vector representing one observation of the signalA 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 Note You can use the output of corrmtx to generate such an array x.You can specify the second input argument p as either:A scalar integer. In this case, the signal subspace dimension is p.A two-element vector. In this case, p(2), the second element of p, represents a threshold that is multiplied by λmin, the smallest estimated eigenvalue of the signal's correlation matrix. Eigenvalues below the threshold λmin*p(2) are assigned to the noise subspace. In this case, p(1) specifies the maximum dimension of the signal subspace.The extra threshold parameter in the second entry in p provides you more flexibility and control in assigning the noise and signal subspaces. The length of the vector w is the computed dimension of the signal subspace. For real-valued input data x, the length of the corresponding power vector pow is given by length(pow) = 0.5*length(w) For complex-valued input data x, pow and w have the same length.[f,pow] = rooteig(...,fs) returns the vector of frequencies f calculated in Hz. You supply the sampling frequency fs in Hz. If you specify fs with the empty vector [], the sampling frequency defaults to 1 Hz.[w,pow] = rooteig(...,'corr') forces the input argument x to be interpreted as a correlation matrix rather than a matrix of signal data. For this syntax, you must supply a square matrix for x, and all of its eigenvalues must be nonnegative. Note You can place the string 'corr' anywhere after p.

[w,pow] = rooteig(x,p)[f,pow] = rooteig(...,fs)[w,pow] = rooteig(...,'corr')

length(pow) = 0.5*length(w)