Cosine Integral (Not in Base Package)

Evaluates the cosine integral for any real non-negative number x. The cosine integral is defined by

ci(x) = gamma + ln(x) + integral of (cos(s) - 1)/s

between 0 and x. gamma is the Euler constant. Details

x is any real nonnegative number.
ci(x) is the result of the calculation of the cosine integral for the given value of x.
error returns any error or warning condition from the VI.

Cosine Integral Details

It is

ci(–x) = ci(x) – i

The algorithm accepts only nonnegative real numbers as input.

The calculation of ci(x) can be done with the help of E(x). See the Sine Integral VI description for more information.

The following diagram shows the graph of the cosine integral in the interval (0,15).