The problem of optimal recovering high-order mixed derivatives of bivariate functions with finite smoothness is studied. On the basis of the truncation method, an algorithm for numerical differentiation is constructed, which is order-optimal both in the sense of accuracy and in terms of the amount of involved Galerkin information.

翻译：研究了有限光滑二元函数的高阶混合导数最优恢复问题。基于截断方法，构造了一种数值微分算法，该算法在精度和所涉及的Galerkin信息量意义上均达到了阶最优。