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Re: Fw: BUG REPORT: unexpected floating point behavior
- To: Stan Malyshev <stas at xpconsulting dot com>
- Subject: Re: Fw: BUG REPORT: unexpected floating point behavior
- From: "Charles S. Wilson" <cwilson at ece dot gatech dot edu>
- Date: Fri, 25 May 2001 10:59:03 -0400
- CC: cygwin at cygwin dot com
- References: <000d01c0e507$64435540$0401a8c0@ntserv>
That's not a bug. It's just the way floating point works (or doesn't
work). It boils down to a problem representing base10 floats with a
32bit base2 packed structure. You need to read up on floating point and
precision. Try google...
--Chuck
Stan Malyshev wrote:
>
> ----- Original Message -----
> From: Stan Malyshev
> To: cygwin@cygwin.com
> Cc: Tennyson Lee
> Sent: Friday, May 25, 2001 3:40 AM
> Subject: BUG REPORT: unexpected floating point behavior
>
> Consider the following unexpected output of a simple loop that increments a
> floating value by 0.1 at every iteration:
>
> #include <stdio.h>
>
> int main() {
>
> float x;
>
> for (x = 0; x < 4; x += 0.1f) {
> printf("x=%f\n", x);
> }
>
> return 0;
> }
>
> ------------------
>
> x=0.000000
> x=0.100000
> x=0.200000
> x=0.300000
> x=0.400000
> x=0.500000
> x=0.600000
> x=0.700000
> x=0.800000
> x=0.900000
> x=1.000000
> x=1.100000
> x=1.200000
> x=1.300000
> x=1.400000
> x=1.500000
> x=1.600000
> x=1.700000
> x=1.800000
> x=1.900000
> x=2.000000
> x=2.100000
> x=2.200000
> x=2.300000
> x=2.400000
> x=2.500000
> x=2.600000
> x=2.700000
> x=2.799999
> x=2.899999
> x=2.999999
> x=3.099999
> x=3.199999
> x=3.299999
> x=3.399999
> x=3.499999
> x=3.599999
> x=3.699999
> x=3.799999
> x=3.899998
> x=3.999998
>
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