mean-power approximation

Chebyshev approximation by the exponent from a rational expression

A method for constructing Chebyshev approximation with relative error of the exponential from a rational expression is proposed.  It implies constructing an intermediate Chebyshev approximation with absolute error by a rational expression of the logarithm of the function being approximated.  The approximation by a rational expression is calculated as the boundary mean-power approximation using an iterative scheme based on the least squares method with two variable weight functions.  The presented results of solving test examples confirm the fast convergence of the metho

Chebyshev approximation of multivariable functions with the interpolation

A method of constructing a Chebyshev approximation of multivariable functions by a generalized polynomial with the exact reproduction of its values at a given points is proposed.  It is based on the sequential construction of mean-power approximations, taking into account the interpolation condition.  The mean-power approximation is calculated using an iterative scheme based on the method of least squares with the variable weight function.  An algorithm for calculating the Chebyshev approximation parameters with the interpolation condition for absolute and relative error is described.  The