sin_integral
Sin-integral-func
Definition:
evaluates
![Si(x)=\int_0^x\frac{\sin u}udu Si(x)=\int_0^x\frac{\sin u}udu](../images/Sin_integral_(function)/math-08c28011c6fde3452b7bcad0a3954c74.png)
The approximation is based on several Chebyshev expansions.
For more information please review the s13adc function in the NAG document.
Parameters:
- x (input, double)
- The argument x of the function.
- Si (output, double)
- the approximation of the formula
![Si(x)=\int_0^x\frac{\sin u}udu Si(x)=\int_0^x\frac{\sin u}udu](../images/Sin_integral_(function)/math-08c28011c6fde3452b7bcad0a3954c74.png)