The Journal of Approximation Theory is devoted to advances in pure and applied approximation theory and related areas. These areas include, among others:? Classical approximation ? Abstract approximation ? Constructive approximation ? Degree of approximation ? Fourier expansions ? Interpolation of operators ? General orthogonal systems ? Interpolation and quadratures ? Multivariate approximation ? Orthogonal polynomials ? Padé approximation ? Rational approximation ? Spline functions of one and several variables ? Approximation by radial basis functions in Euclidean spaces, on spheres, and on more general manifolds ? Special functions with strong connections to classical harmonic analysis, orthogonal polynomial, and approximation theory (as opposed to combinatorics, number theory, representation theory, generating functions, formal theory, and so forth) ? Approximation theoretic aspects of real or complex function theory, function theory, difference or differential equations, function spaces, or harmonic analysis

近似理論雜志致力于純粹和應用近似理論及相關領域的進步。這些領域包括：?經典近似?抽象近似?建設性近似?近似度?傅里葉擴展?運營商的插值?一般正交系統?插值和正交?多變量近似?正交多項式?Padé近似?有理近似?一個和多個變量的樣條函數?在歐幾里德空間，球體和更一般的流形上通過徑向基函數逼近?與經典諧波分析，正交多項式和近似理論有強連接的特殊函數（與組合，數論，表示理論，生成函數，形式理論等相反）?實函數或復函數理論，函數理論，差分或微分方程，函數空間或諧波分析的近似理論方面