s17ajf

Purpose

Synopsis

[fun_value,ifail] = s17ajf(x<,ifail>)

Description

 
 This routine evaluates an approximation to the derivative of the 
 Airy function Ai(x). 
 
 For large negative arguments, it becomes impossible to calculate 
 a result for the oscillating function with any accuracy and so 
                                                       4/7
                                           (    ____  )          
                                           (  \/(pi)  )       
 the routine must fail. This occurs for x<-( ---------)   , where 
                                           ( (epsilon))          
 (epsilon) is the machine precision.
 
 For large positive arguments, where Ai' decays in an essentially 
 exponential manner, there is a danger of underflow so the routine
 must fail.
 

Parameters

s17ajf

Required Input Arguments:

x                                     real

Optional Input Arguments:                       <Default>

ifail                                 integer  -1

Output Arguments:

ifail                                 integer