A Bug in Math.IEERemainder?

[Sunny S]

Hi,

When calculating a remainder, R, as a result of X / Y, you wouldn't expect R
to be greater than Y, right? Wrong!

Math.IEEERemainder( double.MaxValue, 1000.0 ) returns 1.99584030953472E+292.
I understand why and how this happens, but the point is that returning a
value that is greater than the divisor, 1000.0, is completely wrong and no
reason could be used as an excuse.

Incidentally, Math.IEEERemainder( double.MaxValue, 100.0 ) returns 0.0 as
expected.

Sunny S

[Jon Skeet [C# MVP]]

Sunny S <su***@neverland.com> wrote:

When calculating a remainder, R, as a result of X / Y, you wouldn't expect R
to be greater than Y, right? Wrong!

Math.IEEERemainder( double.MaxValue, 1000.0 ) returns 1.99584030953472E+292.
I understand why and how this happens, but the point is that returning a
value that is greater than the divisor, 1000.0, is completely wrong and no
reason could be used as an excuse.

Incidentally, Math.IEEERemainder( double.MaxValue, 100.0 ) returns 0.0 as
expected.

This appears to be fixed in .NET 2.0 beta 2 - at least, the above
returns 368, which I believe to be correct.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Sunny S]

Thanks, Jon. 368 is ok At least it looks like a reasonable trade-off between
accuracy and performanceJ

Sunny S.

"Jon Skeet [C# MVP]" <sk***@pobox.com> wrote in message
news:MP************************@msnews.microsoft.c om...

Sunny S <su***@neverland.com> wrote:

When calculating a remainder, R, as a result of X / Y, you wouldn't
expect R
to be greater than Y, right? Wrong!

Math.IEEERemainder( double.MaxValue, 1000.0 ) returns
1.99584030953472E+292.
I understand why and how this happens, but the point is that returning a
value that is greater than the divisor, 1000.0, is completely wrong and
no
reason could be used as an excuse.

Incidentally, Math.IEEERemainder( double.MaxValue, 100.0 ) returns 0.0 as
expected.

This appears to be fixed in .NET 2.0 beta 2 - at least, the above
returns 368, which I believe to be correct.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Jon Skeet [C# MVP]]

Sunny S <su***@neverland.com> wrote:

Thanks, Jon. 368 is ok At least it looks like a reasonable trade-off between
accuracy and performanceJ

368 is better than okay though - I believe it's the exactly correct
value, given the output of my DoubleConverter which shows the *exact*
value of any double.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too