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

IMSL_ELRJ

IMSL_ELRJ

The IMSL_ELRJ function evaluates Carlson’s elliptic integral of the third kind RJ (x, y, z, ρ).

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

Carlson’s elliptic integral of the third kind is defined to be:

The arguments must be nonnegative. In addition, x + y, x + z, y + z and ρ must be greater than or equal to (5s)1/3 and less than or equal to 0.3(b/5)1/3, where s is the smallest representable floating-point number. Should any of these conditions fail IMSL_ELRJ is set to b, the largest floating-point number.

The IMSL_ELRJ function is based on the code by Carlson and Notis (1981) and the work of Carlson (1979).

Example


The integral RJ (2, 3, 4, 5) is computed.

PRINT, IMSL_ELRJ(2.0, 3.0, 4.0, 5.0)
  0.142976

Syntax


Result = IMSL_ELRJ(X, Y, Z, Rho [, /DOUBLE]

Return Value


The complete elliptic integral RJ (x, y, z, ρ).

Arguments


Rho

Fourth argument for which the function value is desired. It must be positive.

X

First argument for which the function value is desired. It must be nonnegative.

Y

Second argument for which the function value is desired. It must be nonnegative.

Z

Third argument for which the function value is desired. It must be positive.

Keywords


DOUBLE (optional)

If present and nonzero, double precision is used.

Version History


6.4

Introduced



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