Chapter 9: Special Functions

airy_Ai

Evaluates the Airy function.

Synopsis

#include <imsl.h>

float imsl_f_airy_Ai (float x)

The type double function is imsl_d_airy_Ai.

Required Arguments

float x   (Input)
Argument for which the function value is desired.

Return Value

The Airy function evaluated at x, Ai(x).

Description

The airy function Ai(x) is defined to be

The Bessel function Kv(x) is defined in bessel_exp_K0.

If x < -1.31e-2/3, then the answer will have no precision. If x < -1.31e-1/3, the answer will be less accurate than half precision. Here e = imsl_f_machine(4) is the machine precision.

Finally, x should be less than x" so the answer does not underflow. Very approximately, x" = {-1.5lns}2/3, where s = imsl_f_machine(1), the smallest representable positive number.

Example

In this example, Ai(-4.9) is evaluated.

#include <imsl.h>


main()

{

        float   x = -4.9;

        float   ans;


        x = imsl_f_airy_Ai (x);


        printf ("Ai(-4.9) = %f\n", x);

}

Output

Ai(-4.9) = 0.374536


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