!  6.2.js
!  2024-09-07
!  $Id: 6.2.f90 1.1 2024/11/02 12:41:19 s Exp $

!  ex   : E(x)
!  varx : var(x)

integer :: i, j, k, m, n,nn, sumx
integer :: x(36)
real    :: ex, sumv, varx

!  input
n = 6
nn= n*n
k=0
do i = 1, n
    do j = 1, n
        k = k + 1
        x(k) = i* j
    end do
end do

!  calculation
m    = n * n
sumx = sum(x)
ex   = sumx / real(m)
sumv = 0.0
do k = 1, nn
    sumv = sumv + (x(k) - ex) ** 2
end do
varx = sumv / real(m)

!  output
print *, '6.2.f90'
print '(4a5,2a10,a15)', "k","i","j","x","E(x)","x-E(x)","(x-E(x))^2"
print *,'-------------------------------------------------------'
k = 0
do i = 1, n
    do j = 1, n
        k = k + 1
        print '(4i5,2f10.2,f15.2)', k, i, j, x(k),ex,(x(k)-ex),((x(k)-ex)**2)
    end do
end do
print *,'-------------------------------------------------------'

print '(a10,i10)',   "m=",      m
print '(a10,f10.2)', "E(x)=",   ex
print '(a10,f10.2)', "var(x)=", varx
end
!  end