For the given sample points , and matrix formed by covariance function with sample points as parameters , when the number of sample points approaches infinite , it is proven that this matrix spectrum will approach the spectral approach theorem for positive - definite kernel of integral equation 對給定的樣本點,由樣本點為變量的協(xié)方差函數(shù)構(gòu)成的矩陣,當(dāng)樣本點個數(shù)趨于無窮大時,證明此矩陣譜逼近于積分方程正定核的譜逼近定理。