function [airesult,x]=ai(x);
airesult=[];
persistent ai aifcs aigcs first firstCall naif naig theta x3sml xm xmax xmaxt z ; if isempty(firstCall),firstCall=1;end;
if isempty(airesult), airesult=0; end;
if isempty(aifcs), aifcs=zeros(1,9); end;
if isempty(aigcs), aigcs=zeros(1,8); end;
if isempty(theta), theta=0; end;
if isempty(x3sml), x3sml=0; end;
if isempty(xm), xm=0; end;
if isempty(xmax), xmax=0; end;
if isempty(xmaxt), xmaxt=0; end;
if isempty(z), z=0; end;
if isempty(naif), naif=0; end;
if isempty(naig), naig=0; end;
%***BEGIN PROLOGUE AI
%***PURPOSE Evaluate the Airy function.
%***LIBRARY SLATEC (FNLIB)
%***CATEGORY C10D
%***TYPE SINGLE PRECISION (AI-S, DAI-D)
%***KEYWORDS AIRY FUNCTION, FNLIB, SPECIAL FUNCTIONS
%***AUTHOR Fullerton, W., (LANL)
%***DESCRIPTION
%
% AI(X) computes the Airy function Ai(X)
% Series for AIF on the interval -1.00000D+00 to 1.00000D+00
% with weighted error 1.09E-19
% log weighted error 18.96
% significant figures required 17.76
% decimal places required 19.44
%
% Series for AIG on the interval -1.00000D+00 to 1.00000D+00
% with weighted error 1.51E-17
% log weighted error 16.82
% significant figures required 15.19
% decimal places required 17.27
%
%***REFERENCES (NONE)
%***ROUTINES CALLED AIE, CSEVL, INITS, R1MACH, R9AIMP, XERMSG
%***REVISION HISTORY (YYMMDD)
% 770701 DATE WRITTEN
% 890531 Changed all specific intrinsics to generic. (WRB)
% 890531 REVISION DATE from Version 3.2
% 891214 Prologue converted to Version 4.0 format. (BAB)
% 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
% 900326 Removed duplicate information from DESCRIPTION section.
% (WRB)
% 920618 Removed space from variable names. (RWC, WRB)
%***end PROLOGUE AI
if isempty(first), first=false; end;
if firstCall, aifcs(1)=[-.03797135849666999750e0]; end;
if firstCall, aifcs(2)=[.05919188853726363857e0]; end;
if firstCall, aifcs(3)=[.00098629280577279975e0]; end;
if firstCall, aifcs(4)=[.00000684884381907656e0]; end;
if firstCall, aifcs(5)=[.00000002594202596219e0]; end;
if firstCall, aifcs(6)=[.00000000006176612774e0]; end;
if firstCall, aifcs(7)=[.00000000000010092454e0]; end;
if firstCall, aifcs(8)=[.00000000000000012014e0]; end;
if firstCall, aifcs(9)=[.00000000000000000010e0]; end;
if firstCall, aigcs(1)=[.01815236558116127e0]; end;
if firstCall, aigcs(2)=[.02157256316601076e0]; end;
if firstCall, aigcs(3)=[.00025678356987483e0]; end;
if firstCall, aigcs(4)=[.00000142652141197e0]; end;
if firstCall, aigcs(5)=[.00000000457211492e0]; end;
if firstCall, aigcs(6)=[.00000000000952517e0]; end;
if firstCall, aigcs(7)=[.00000000000001392e0]; end;
if firstCall, aigcs(8)=[.00000000000000001e0]; end;
if firstCall, first=[true]; end;
firstCall=0;
%***FIRST EXECUTABLE STATEMENT AI
if( first )
[naif ,aifcs]=inits(aifcs,9,0.1.*r1mach(3));
[naig ,aigcs]=inits(aigcs,8,0.1.*r1mach(3));
%
x3sml = r1mach(3).^0.3334;
xmaxt =(-1.5.*log(r1mach(1))).^0.6667;
xmax = xmaxt - xmaxt.*log(xmaxt)./(4.0.*sqrt(xmaxt)+1.0) - 0.01;
end;
first = false;
%
if( x<(-1.0) )
[x,xm,theta]=r9aimp(x,xm,theta);
airesult = xm.*cos(theta);
csnil=dbstack(1); csnil=csnil(1).name(1)~='@';
if csnil&&~isempty(inputname(1)), assignin('caller','FUntemp',x); evalin('caller',[inputname(1),'=FUntemp;']); end
return;
%
elseif( x<=1.0 ) ;
z = 0.0;
if( abs(x)>x3sml )
z = x.^3;
end;
airesult = 0.375 +(csevl(z,aifcs,naif)-x.*(0.25+csevl(z,aigcs,naig)));
csnil=dbstack(1); csnil=csnil(1).name(1)~='@';
if csnil&&~isempty(inputname(1)), assignin('caller','FUntemp',x); evalin('caller',[inputname(1),'=FUntemp;']); end
return;
%
elseif( x>xmax ) ;
%
airesult = 0.0;
xermsg('SLATEC','AI','X SO BIG AI UNDERFLOWS',1,1);
else;
airesult = aie(x).*exp(-2.0.*x.*sqrt(x)./3.0);
csnil=dbstack(1); csnil=csnil(1).name(1)~='@';
if csnil&&~isempty(inputname(1)), assignin('caller','FUntemp',x); evalin('caller',[inputname(1),'=FUntemp;']); end
return;
end;
%
csnil=dbstack(1); csnil=csnil(1).name(1)~='@';
if csnil&&~isempty(inputname(1)), assignin('caller','FUntemp',x); evalin('caller',[inputname(1),'=FUntemp;']); end
end
%DECK ALBETA
