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; Difference between 2 arrays of 1 dimension

; Function; return 0 si no difference, 1 otherwise.
; give also average value and standard deviation of the difference
; ex:   diff= diff_2arrays1D(array1,array2, average,sigma)

; P. Robert, CETP, January 2007

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  FUNCTION diff_2arrays1D, array1,array2, average,sigma

  average=999.999
  sigma=999.999
  n1= N_elements(array1)
  n2= N_elements(array2)

  IF (n1 NE n2 ) THEN RETURN, 1 ELSE n=n1

  diff=array1-array2

  average= total(diff)/float(n)
  var= total((diff-average)^2)/float(n)
  sigma=sqrt(var)

  IF (abs(average) LT 1.e-30 and sigma LT 1.e-30) THEN rep=0 ELSE rep=1

  RETURN, rep
  END
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