Chapter 8: Airy Functions

AIDE

This function evaluates the exponentially scaled derivative of the Airy function.

Function Return Value

AIDE — Function value.   (Output)
The derivative of the Airy function for negative arguments and the exponentially scaled derivative of the Airy function, eζAiʹ(X), for positive arguments where

Required Arguments

X — Argument for which the Airy function value is desired.   (Input)

FORTRAN 90 Interface

Generic:                              AIDE (X)

Specific:                             The specific interface names are S_AIDE and D_AIDE.

FORTRAN 77 Interface

Single:                                AIDE (X)

Double:                              The double precision name is DAIDE.

Description

The exponentially scaled derivative of the Airy function is defined to be

If , then the answer will have no precision. If , then the answer will be less accurate than half precision. Here, ε = AMACH(4) is the machine precision.

Example

In this example, AIDE(0.49) is computed and printed.

 

      USE AIDE_INT

      USE UMACH_INT

 

      IMPLICIT   NONE

!                                 Declare variables

      INTEGER    NOUT

      REAL       VALUE, X

!                                 Compute

      X     = 0.49

      VALUE = AIDE(X)

!                                 Print the results

      CALL UMACH (2, NOUT)

      WRITE (NOUT,99999) X, VALUE

99999 FORMAT (' AIDE(', F6.3, ') = ', F6.3)

      END

Output

 

AIDE( 0.490) = -0.284



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