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IMSL_KELVIN_BEI0

IMSL_KELVIN_BEI0

The IMSL_KELVIN_BEI0 function evaluates the Kelvin function of the first kind, bei, of order zero.

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

The Kelvin function bie0(x) is defined to be . The Bessel function J0(x) is defined:

In IMSL_KELVIN_BEI0, x must be less than 119.

If the keyword DERIVATIVE is set, the function bei0′(x) is defined to be:

If the keyword DERIVATIVE is set and |x| > 119, NaN is returned.

The IMSL_KELVIN_BEI0 function is based on the work of Burgoyne (1963).

Example


In this example, bei0(0.4) and bei0′(0.6) are evaluated.

PRINT, IMSL_KELVIN_BEI0(0.4)
  0.0399982
PRINT, IMSL_KELVIN_BEI0(0.6, /DERIVATIVE)
  0.299798

Syntax


Result = IMSL_KELVIN_BEI0(X [, DERIVATIVE=value] [, /DOUBLE])

Return Value


The value of the Kelvin function of the first kind, bei, of order zero evaluated at x.

Arguments


X

Argument for which the function value is desired.

Keywords


DERIVATIVE (optional)

If present and nonzero, then the derivative of the Kelvin function of the first kind, bei, of order zero evaluated at x is computed.

DOUBLE (optional)

If present and nonzero, then double precision is used.

Version History


6.4

Introduced

See Also


IMSL_KELVIN_BER0, IMSL_KELVIN_KEI0, IMSL_KELVIN_KER0



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