|
|
◆ Ei_sub()
| Sub Ei_sub |
( |
Ret As |
Double, |
|
|
X As |
Double, |
|
|
Optional Info As |
Long |
|
) |
| |
指数積分 Ei(x) (サブルーチン版)
- 目的
- 指数積分 Ei(x) を求める.
Ei(x) = -∫ exp(-t)/t dt [-x, ∞] = - E1(-x)
Function E1(X As Double, Optional Info As Long) As Double 指数積分 E1(x)
Function Ei(X As Double, Optional Info As Long) As Double 指数積分 Ei(x)
- 引数
-
| [out] | Ret | 指数積分 Ei(x). |
| [in] | X | 引数 x. (X <> 0) |
| [out] | Info | (省略可)
= 0: 正常終了.
= 1: 浮動小数点値域エラー. |
- 出典
- boost/math/special_functions
|