main (16) (1).f95

PROGRAM interpolation
real,dimension(8,8)::six
real,dimension(8)::dif,inter,temp
real,dimension(9)::f
real,dimension(4)::Y,X
real::n,a,b
integer j,i
six =0
G=0
X=(/1000,2000,25000,42195/)
Y(1)=(2*60)+11.96
Y(2)=(4*60)+44.79
Y(3)=(1*3600)+(12*60)+(25)
Y(4)=(2*3600)+(1*60)+(39)
dif=(/100,200,400,800,1500,5000,10000,30000/)
six(1,1)=9.58
six(2,1)=19.19
six(3,1)=43.03
six(4,1)=(1*60)+(40.91)
six(5,1)=(3*60)+(26.00)
six(6,1)=(12*60)+(35.36)
six(7,1)=(26*60)+(11.00)
six(8,1)=(1*3600)+(26*60)+(47.40)
do i=2,8
    do j=i,8
    six(j,i)=(six(j,i-1)-six(j-1,i-1))/(dif(j)-dif(j-i+1))
    enddo
enddo
do i=1,8
    print *,(six(i,j), j=1,8)
enddo
do j=1,4
 n=X(j)
 !!?? this loop is not needed and the next loop is 7,1,-1
 do i=1,8
 f(i+1)=six(i,i)
 enddo
 do i=8,1,-1
 f(i)=(f(i+1)*(n-dif(i)))+six(i,i)
 enddo
 print *,'THE REAL VALUE IS', Y(J),'THE INTERPOLATED VALUE IS ', f(1)
enddO
!!?? you should take the log of only 1st column and then construct the table
!!?? usin log of dif
do i=1,8
    do j=1,8
        six(i,j)=log(six(I,j))
    enddo
enddo
do j=1,4
!!?? n also has to be log(x(j))
 n=X(j)
 do i=1,8
 f(i+1)=six(i,i)
 enddo
 do i=8,1,-1
 f(i)=(f(i+1)*(n-dif(i)))+six(i,i)
 enddo
 print *,'THE REAL VALUE IS', Y(J),'THE INTERPOLATED VALUE IS ', EXP(f(1))
enddO 
end program interpolation