[Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator

[Jordi Gutiérrez Hermoso]

Follow-up Comment #25, bug #42589 (project octave):

> In double precision, 10, 0.1 and 1.0 are represented exactly

This is false, the only values that can be represented exactly in hardware
floats are those where the numerator is a power of 2, which 1/10 is not (it
has a pesky 5 in there, and 1/5 has a repeating binary expansion). That is why
0.3 - 0.2 - 0.1 is not 0 in any language that uses hardware floats.

This is not really a bug, but if it's trivial to perform the computation in a
way that matches Matlab's own error (there *has* to be an error, since there
can't be exact representation), let's pick Matlab's error.

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