wecopttool.core.real_to_complex

real_to_complex(fd, zero_freq=True)[source]

Convert from two real amplitudes to one complex amplitude per frequency.

The input is a real 2D array with each column containing the real and imaginary components of the Fourier coefficients for some response, excluding the imaginary component of the highest frequency (2-point wave). The column length is 2*nfreq. The entries of a column representing a response x are x=[X0, Re(X1), Im(X1), ..., Re(Xn)].

Returns a complex 2D array with each column containing the complex Fourier coefficients. Columns are length nfreq+1, and the first row corresponds to the real-valued zero-frequency (mean, DC) components. The entries of a column representing a response x are x=[X0, X1, ..., Xn].

If zero_freq = False, the mean (DC) component X0 is excluded, and the column length is reduced by 1.

Parameters:

fd (ArrayLike) – Array containing the real and imaginary components of the Fourier coefficients.
zero_freq (bool | None) – Whether the mean (DC) component is included.

Return type:

ndarray