# naginterfaces.library.specfun.integral_​sin¶

naginterfaces.library.specfun.integral_sin(x)[source]

integral_sin returns the value of the sine integral

.

For full information please refer to the NAG Library document for s13ad

Parameters
xfloat

The argument of the function.

Returns
sixfloat

The value of the sine integral

Notes

integral_sin calculates an approximate value for .

For it is based on the Chebyshev expansion

For , where is an implementation-dependent number,

where and , .

For , to within machine precision.

References

NIST Digital Library of Mathematical Functions