====== 지수합 함수 (Exponential Sum Function) ====== ===== 정의 ===== $$ \begin{displaymath}\begin{split} e_{n}(x) &= \sum_{k=0}^{n} \frac{x^{k}}{k!} \\ &= \frac{e^{x} \Gamma(n+1,x)}{\Gamma(n+1)} \end{split}\end{displaymath} $$ set size 1.0 set xrange [0:10] set yrange [0:10] set zeroaxis set title "Exponential Sum Function" f(x,n) = ((exp(x))*(gamma(n+1)-igamma(n+1,x)))/(gamma(n+1)) plot f(x,0.0) title "n=0", \ f(x,1.0) title "n=1", \ f(x,2.0) title "n=2", \ f(x,3.0) title "n=3" 단, $\Gamma(x)$는 [[감마함수]], $\Gamma(a,x)$는 [[불완전 감마함수]]이다. ---- * [[함수]]