Is this a bug? different results when performing simple math operation (A * (B - C)) with scalars or variables

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Hello everybody,
I am performing same operation A * (B - C) two times. First with variables, then with numbers (scalars). I get different results.
I am providing the output from the command window.
Can somebody please help on this issue?
Thank you,

Accepted Answer

Walter Roberson
Walter Roberson on 11 Jan 2022
If you use
format long g
you will see that ptfDur is not exactly the same as the constant 4.5501 . For example, test
ptfDur - 4.5501
and you will see that the result is non-zero.
Working backwards
C1 = 3 - (-134684353.5829 / 86885000)
C1 =
4.55014506051562
C2 = 3 - (-134680438.5 / 86885000)
C2 =
4.5501
C1 - C2
ans =
4.50605156236961e-05
Your actual value is about 4E-5 larger than was being displayed, because the default format short only displays 4 digits.

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