Precision[N[1.0, 20]] Precision[N[1, 20]]
It would be so much more intuitive and less error prone, if
Precision[N[1.0, 20]] would be
20 and not
MachinePrecision. Why do I have to explicitly use
N[Rationalized[1.0], 20] to upgrade the precision?
If it is about the warning messages during the calculations, Mathematica could return a warning already at the
Precision[N[1.0, 20]] step.
I am not attempting to use
N for rounding. I also understand the difference between
MachinePrecision and arbitrary precision, which is very well described in this answer.
I want to know, why does Mathematica not consider the description of the number existing in the underling binary representation as exact if I apply
N, and why I need to wrap it with
Is it performance?
Is it some deep semantic meaning of
SetPrecision any different from