mathFunctions (`skrf.mathFunctions`)

Provides commonly used mathematical functions.

Mathematical Constants

Some convenient constants are defined in the skrf.constants module.

`complex_2_reim`(z)	Return real and imaginary parts of a complex number.
`complex_2_magnitude`(z)	Return the magnitude of the complex argument.
`complex_2_db`(z)	Return the magnitude in dB of a complex number (as \(20\log_{10}(\|z\|)\))..
`complex_2_db10`(z)	Return the magnitude in dB of a complex number (as \(10\log_{10}(\|z\|)\)).
`complex_2_radian`(z)	Return the angle complex argument in radian.
`complex_2_degree`(z)	Returns the angle complex argument in degree.
`complex_2_magnitude`(z)	Return the magnitude of the complex argument.
`complex_2_quadrature`(z)	Take a complex number and returns quadrature, which is (length, arc-length from real axis)
`complex_components`(z)	Break up a complex array into all possible scalar components.

`magnitude_2_db`(z[, zero_nan])	Convert linear magnitude to dB.
`mag_2_db`(z[, zero_nan])	Convert linear magnitude to dB.
`mag_2_db10`(z[, zero_nan])	Convert linear magnitude to dB.
`db_2_magnitude`(z)	Convert dB to linear magnitude.
`db_2_mag`(z)	Convert dB to linear magnitude.
`db10_2_mag`(z)	Convert dB to linear magnitude.

`unwrap_rad`(phi)	Unwraps a phase given in radians.
`sqrt_phase_unwrap`(z)	Take the square root of a complex number with unwrapped phase.

`radian_2_degree`(rad)	Convert angles from radians to degrees.
`degree_2_radian`(deg)	Convert angles from degrees to radians.
`np_2_db`(x)	Converts a value in Nepers (Np) to decibel (dB).
`db_2_np`(db)	Converts a value in decibel (dB) to neper (Np).
`feet_2_meter`([feet])	Convert length in feet to meter.
`meter_2_feet`([meter])	Convert length in meter to feet.
`db_per_100feet_2_db_per_100meter`([...])	Convert attenuation values given in dB/100ft to dB/100m.

These conversions are useful for wrapping other functions that don’t support complex numbers.

`complex2Scalar`(z)	Serialize a list/array of complex numbers
`scalar2Complex`(s)	Unserialize a list/array of real and imag numbers into a complex array.

`dirac_delta`(x)	Calculate Dirac function.
`neuman`(x)	Calculate Neumans number.
`null`(A[, eps])	Calculate the null space of matrix A.
`cross_ratio`(a, b, c, d)	Calculate the cross ratio of a quadruple of distinct points on the real line.

`set_rand_rng`(rng)	Set the global `numpy` random number generator instance for generating random numbers in scikit-rf.
`rand_rng`()	Obtain the global `numpy` random number generator instance.
`rand_c`(*size[, rng])	Creates a complex random array of shape s.

`psd2TimeDomain`(f, y[, windowType])	Convert a one sided complex spectrum into a real time-signal.
`rational_interp`(x, y[, d, epsilon, axis, ...])	Interpolates function using rational polynomials of degree d.
`ifft`(x)	Transforms S-parameters to time-domain bandpass.
`irfft`(x[, n])	Transforms S-parameters to time-domain, assuming complex conjugates for values corresponding to negative frequencies.
`is_square`(mat)	Tests whether mat is a square matrix.
`is_symmetric`(mat[, tol])	Tests mat for symmetry.
`is_Hermitian`(mat[, tol])	Tests whether mat is Hermitian.
`is_positive_definite`(mat[, tol])	Tests mat for positive definiteness.
`is_positive_semidefinite`(mat[, tol])	Tests mat for positive semidefiniteness.
`get_Hermitian_transpose`(mat)	Returns the conjugate transpose of mat.
`sqrt_known_sign`(z_squared, z_approx)	Return the square root of a complex number, with sign chosen to match z_approx.
`find_correct_sign`(z1, z2, z_approx)	Create new vector from z1, z2 choosing elements with sign matching z_approx.
`find_closest`(z1, z2, z_approx)	Return z1 or z2 depending on which is closer to z_approx.
`inf_to_num`(x)	Convert inf and -inf's to large numbers.
`rsolve`(A, B)	Solves x @ A = B.
`nudge_eig`(mat[, cond, min_eig])	Nudge eigenvalues with absolute value smaller than max(cond * max(eigenvalue), min_eig) to that value.