33 lines
937 B
Markdown
33 lines
937 B
Markdown
[sf.cmath.expint]
|
||
|
||
# 29 Numerics library [[numerics]](./#numerics)
|
||
|
||
## 29.7 Mathematical functions for floating-point types [[c.math]](c.math#sf.cmath.expint)
|
||
|
||
### 29.7.6 Mathematical special functions [[sf.cmath]](sf.cmath#expint)
|
||
|
||
#### 29.7.6.15 Exponential integral [sf.cmath.expint]
|
||
|
||
[ð](#lib:expint)
|
||
|
||
`floating-point-type expint(floating-point-type x);
|
||
float expintf(float x);
|
||
long double expintl(long double x);
|
||
`
|
||
|
||
[1](#1)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10525)
|
||
|
||
*Effects*: These functions compute the exponential integral
|
||
of their respective argumentsx[.](#1.sentence-1)
|
||
|
||
[2](#2)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10531)
|
||
|
||
*Returns*: Ei(x),
|
||
where Ei is given by Formula [29.35](#eq:sf.cmath.expint) andx is x[.](#2.sentence-1)
|
||
|
||
Ei(x)=ââ«ââxeâttdt(29.35)
|