Symmetric matrices are often used to represent quadratic forms.
NMath provides symmetric matrix classes for single- and double-precision floating point numbers. The classnames are FloatSymmetricMatrix and DoubleSymmetricMatrix. Hermitian matrices are a generalization of symmetric matrices for complex types (Section 17.4).
For efficiency, only the upper triangle is stored. The storage scheme is the same as for an upper triangular matrix (Section 17.2).