program eigen1
	common/jac01/n,a(40,40),s(40,40)
	print*,'GIVE ME THE DIMENSION OF THE MATRIX(ONE NUMBER)'
	read(5,*)n
	print*,'GIVE ME THE MATRIX NOW'
	do 9 i=1,n
    9  read(5,*) (a(i,j),j=1,n)
	write(6,7)
    7  format(1h1,' input matrix')
	do 10 i=1,n
   10  write(6,8) (a(i,j),j=1,n)
    1  format(i2)
    2  format(10f7.3)
	call jacb
	write(6,4)
	do 3 i=1,n
	write(6,5)a(i,i)
    3  write(6,6)(s(j,i),j=1,n)
    4  format(1h1,' solutions for this eigenvalue problem',//)
    5  format(1h ,' eigenvalue =',f9.3,//,' eigenvector is')
    6  format(1h ,30x,f9.3)
    8  format(1h ,20f6.2)
	stop
	end
	subroutine jacb
	common/jac01/n,a(40,40),s(40,40)
	indic=0
  151  vi=0.0
	do 106 i=1,n
	do 106 j=1,n
	if(i-j)107,206,107
  107  vi=vi+a(i,j)**2
	s(i,j)=0
	go to 106
  206  s(i,j)=1.0
  106  continue
	vi=sqrt(vi)
	vf=vi*0.1e-07
	an=n
  128  vi=vi/an
  137  iq=1
  124  iq=iq+1
	ip=0
  121  ip=ip+1
	if(a(ip,iq))108,120,109
  108  if(-a(ip,iq)-vi)120,112,112
  109  if(a(ip,iq)-vi)120,112,112
  112  indic=1
	alam=-a(ip,iq)
	amu=0.5*(a(ip,ip)-a(iq,iq))
	if(amu)113,114,114
  113  sgn=-1.0
	go to 115
  114  sgn=+1.0
  115 omega=sgn*alam/sqrt(alam**2+amu**2)
	stht=omega/sqrt(2.0+2.0*sqrt(1.0-omega**2))
	ctht=sqrt(1.0-stht**2)
	do 116 i=1,n
	if(i-ip)117,118,117
  117  if(i-iq)119,118,119
  119  aipi=a(ip,i)*ctht-a(iq,i)*stht                    
	aiqi=a(ip,i)*stht+a(iq,i)*ctht
	a(ip,i)=aipi
	a(iq,i)=aiqi
  118  aipi=s(i,ip)*ctht-s(i,iq)*stht
	aiqi=s(i,ip)*stht+s(i,iq)*ctht
	s(i,ip)=aipi
  116  s(i,iq)=aiqi
	aipi=a(ip,ip)*ctht**2+a(iq,iq)*stht**2-2.*a(ip,iq)*stht*ctht
	aiqi=a(ip,ip)*stht**2+a(iq,iq)*ctht**2
     1        +2.0*a(ip,iq)*stht*ctht
	aipiq=(a(ip,ip)-a(iq,iq))*ctht*stht
     1        +a(ip,iq)*(ctht**2-stht**2)
	a(ip,ip)=aipi
	a(iq,iq)=aiqi
	a(ip,iq)=aipiq
	a(iq,ip)=a(ip,iq)
	do 123 i=1,n
	a(i,ip)=a(ip,i)
  123  a(i,iq)=a(iq,i)
  120  if(ip-iq+1)121,122,122
  122  if(iq-n)124,125,125
  125  if(indic)126,127,126
  126  indic=0
	go to 137
  127  if(vi-vf)129,129,128
  129  return
	end