Exponential fitting of restricted rational approximations to the exponential function
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Let Rn/m(z, γ)=Pn(z; γ)/(1-γz)m be a restricted rational approximation to exp(z), zεℂ, of order n for all real γ. In this paper we discuss how γ can be used to obtain fitting at a real non-positive point z1. It is shown that there are exactly min(n+1, m) different positive values of γ with this property.
KeywordsRational Approximation Laguerre Polynomial Exponential Fitting Real Polis Pade Approximation
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