on the case where the function is represented in terms of large‐scale matrix‐valued factors.
We propose a subspace projection method to obtain reduced approximations of this function
by interpolation techniques. The ℒ∞‐norms are computed for the resulting reduced
functions, then the subspaces are refined by means of the optimizer of the ℒ∞‐norm of the
reduced function. In this way we obtain much better performance compared to existing …