>  Docs Center  >  IDL Reference  >  Advanced Math and Stats  >  IMSL_ELK

IMSL_ELK

IMSL_ELK

The IMSL_ELK function evaluates the complete elliptic integral of the kind K(x).

This routine requires an IDL Advanced Math and Stats license. For more information, contact your sales or technical support representative.

The complete elliptic integral of the first kind is defined to be:

The argument x must satisfy 0 ≤ x < 1; otherwise, IMSL_ELK returns the largest representable floating-point number.

The function K(x) is computed using IMSL_ELRF and the relation K(x) = RF(0, 1 − x, 1).

Example


The integral K(0) is evaluated.

PRINT, IMSL_ELK(0.0)
  1.57080

Syntax


Result = IMSL_ELK(X [, /DOUBLE]

Return Value


The complete elliptic integral K(x).

Arguments


X

Argument for which the function value is desired.

Keywords


DOUBLE (optional)

If present and nonzero, double precision is used.

Version History


6.4

Introduced

See Also


IMSL_ELRF



© 2019 Harris Geospatial Solutions, Inc. |  Legal
My Account    |    Store    |    Contact Us