Cos_integral
Definition:
/math-8993703d9fadad35e13539d3e88daeb5.png "Ci=cos\_integral(x)")
evaluates
where /math-ae539dfcc999c28e25a0f3ae65c1de79.png "\gamma")
denotes Euler's constant. The approximation is based on several Chebyshev expansions.
For more information please review the s13acc function in the NAG document.
Parameters:
- x (input, double)
- The argument x of the function.
- Constraint: x>0.0
/math-6fd5bce0a0270467f657066323880d96.png "Ci")
(output, double)- The approximation of the formula
/math-97074ff222cf3d9c9b4fe372a9f5a8a4.png "C_i\left( x\right) =y+\ln x+\int_0^x\frac{\cos u-1}udu")
,x>0