pfapack.ctypes module

pfapack.ctypes.from_exp(x, exp)

Convert pfapack overflow-safe representation (x, exponent) scalar number.

Overflows are converted to infinities.

pfapack.ctypes.pfaffian(matrix: ndarray, uplo: str = 'U', method: str = 'P', avoid_overflow: bool = False) → float | complex

Compute Pfaffian.

Parameters:

• matrix (numpy.ndarray) – Square skew-symmetric matrix.

• uplo (str) – If ‘U’ (‘L’), the upper (lower) triangle of the matrix is used.

• method (str) – If ‘P’ (‘H’), the Parley-Reid (Householder) algorithm is used.

• avoid_overflow (bool) – If True, take special care to avoid numerical under- or overflow (at the cost of possible additional round-off errors).

Returns:

The Pfaffian of the matrix.

Return type:

float | complex

Raises:

• InvalidDimensionError – If the matrix is not square or has odd dimensions.

• InvalidParameterError – If uplo or method parameters are invalid.

• ComputationError – If the computation fails.