Linearly combine the gram matrices. If no weights are given, an unweighted combination is computed.
gram = combine(gramObj, optList)
|optList||-||list of NAME,VALUE option pairs|
|'Weights'||-||Vector of weights for linear combination. To guarantee positive semidefiniteness, non-negative weights can be used. Alternatively, weights can be determined using SDP.|
|'Kernels'||-||A permutation of that indicates the mapping of weights to kernels.|