pipes

      program gauss_seidel_iterative
      implicit double precision (a-h,o-z)
      parameter (kdim=20)
      dimension T(11,11), C(11,11), R(11,11), roi(11)
      agog(X)=A0+A1*X+A2*(X**2)+A3*(X**3)
      olok(i)=(2/10)*(roi(i)+4*roi(i+1)+roi(i+2))*(1/6)


      write(*,*)' Enter Relaxation Factor'
      read(*,*)omega
      write(*,*)' Enter epsilon(sfalma)'
      read(*,*)eps

c
      do i=1,11
         do j=1,11
            T(i,j)=400
         ENDDO
      ENDDO

      do i=1,11
         do j=1,11
            C(i,j)=0
         ENDDO
      ENDDO

      do i=1,11
         T(i,1)=220
      enddo
c     GRAMMIKH PAREMVOLH 1
      T(11,11)=615
      T(1,11)=650
      remold=0

      DIFF1=(T(11,11)-T(11,1))/10

      do j=2,10
         T(11,j)=T(11,j-1)+DIFF1
      ENDDO

c     grammikh paremvolh1 telos
c     GRAMMIKH PAREMVOLH 2
      DIFF2=(T(1,11)-T(1,1))/10
      do j=2,10
         T(1,j)=T(1,j-1)+DIFF2
      enddo
c     grammikh paremvolh2 telos

      do K=1,10**6-1
        do i=2,10
          do j=2,10

           IF(j.lt.10) THEN
           T(i,j)=0.25*(T(i+1,j)+T(i-1,j)+T(i,j+1)+T(i,j-1))

           ELSEIF(j.eq.10) THEN !IF(j.eq.10) THEN
           T(i,j)=(1.d0/3.d0)*( T(i+1,j)+T(i-1,j)+T(i,j-1) )

           ENDIF
          T(i,j) = omega*T(i,j) + (1.d0-omega)*C(i,j)
          q=(T(i,j)-C(i,j))/C(i,j)
          R(i,j)=abs(q)
          !=err
          C(i,j)=T(i,j)
      ENDDO
      ENDDO

      !err0=1e-6

      !sum=0
      !do i=2,10
      !   do j=2,10
      !      sum=R(i,j)+sum
      !   enddo
      !enddo

      !avgsf=sum/90        !90=(N-2)*(N-1)

      !if (avgsf.le.eps) THEN
      !exit
      !endif

      err0=R(2,2)
      do i=2,10
         do j=2,9
            if (R(i,j).gt.err0) THEN
            err0=R(i,j)
            endif
          enddo
      enddo


      if (err0.le.eps) THEN
      EXIT
      endif


      ENDDO



      do i=2,10
            T(i,11)=T(i,10)
      enddo

      open(1,file='solution12.dat')
      do j=1,11
            write(1,21) (T(i,j), i=1,11)
  21      format(50(f10.5,3x))
      enddo
      write (1,*) K, omega
      open (2,file='timesAD.txt')
      do i=1,11
            write(2,*) T(11,i)
      enddo
      close(2)

      !roh
      open(3,file='COEF.TXT')

      READ (3,*) A0,A1,A2,A3
      CLOSE (3)
      do X=1,11
      !write(3,*) agog(x)
      roi(X) = -agog(X)*(T(11,X)-T(10,X))/10
      write(*,*) roi(X)
      write(1,*) roi(X)

      enddo


      !integraltion
      sum=0

      !dh=2/(N-1) !2/(N-1)
      do i=1,9,2
         sum = sum + olok(i)
      enddo
      write(1,*) sum
      write(1,*) 'THERMIKI ROH =',sum,' W/m'
      close(1)





      !stop

      END