c
c     Numerical Analysis:
c     The Mathematics of Scientific Computing
c     D.R. Kincaid & E.W. Cheney
c     Brooks/Cole Publ., 1990
c
c     Section 4.3 
c
c     Example of basic Gaussian elimination with pivoting  
c
c
c     file: pbgauss.f
c
      parameter (n = 2)
      dimension a(n,n)
      integer p(n)
      data (a(1,j),j=1,n) /10.0e-8,1.0/
      data (a(2,j),j=1,n) /1.0,1.0/
      data (p(i),i=1,n) /2,1/
c
      print *
      print *,' Naive Gaussian elimination with pivoting'
      print *,' Section 4.3, Kincaid-Cheney'
      print *
c
      do 4 k=1,n-1
         do 3 i=k+1,n      
            z = a(p(i),k)/a(p(k),k)       
            a(p(i),k) = 0.0
            do 2 j=k+1,n    
               a(p(i),j) = a(p(i),j) - z*a(p(k),j)      
 2          continue
 3       continue  
 4    continue    
c
      do 6 i=1,n
         do 5 j=1,n
            print 7,i,j,a(i,j)
 5       continue
 6    continue
c
 7    format (3x,'a(',i2,',',i2,') =',e13.6)
      stop
      end