Re: [Help-gsl] Check for DENORMAL (subnormal) numbers failed (iee-utils/test.c (185))

[Stephan Petzchen]

SOLVED! AS so often tiny typo big effect...sorry for disturbing.....

Here is now the correct result:

Run: 0
Float: FLT_MIN/2^1: 5,877472E-39
Sign: +
Exponent: -127
Mantisse: 10000000000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 1
Float: FLT_MIN/2^2: 2,938736E-39
Sign: +
Exponent: -127
Mantisse: 01000000000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 2
Float: FLT_MIN/2^3: 1,469368E-39
Sign: +
Exponent: -127
Mantisse: 00100000000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 3
Float: FLT_MIN/2^4: 7,34684E-40
Sign: +
Exponent: -127
Mantisse: 00010000000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 4
Float: FLT_MIN/2^5: 3,67342E-40
Sign: +
Exponent: -127
Mantisse: 00001000000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 5
Float: FLT_MIN/2^6: 1,83671E-40
Sign: +
Exponent: -127
Mantisse: 00000100000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 6
Float: FLT_MIN/2^7: 9,18355E-41
Sign: +
Exponent: -127
Mantisse: 00000010000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 7
Float: FLT_MIN/2^8: 4,591775E-41
Sign: +
Exponent: -127
Mantisse: 00000001000000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 8
Float: FLT_MIN/2^9: 2,295887E-41
Sign: +
Exponent: -127
Mantisse: 00000000100000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 9
Float: FLT_MIN/2^10: 1,147944E-41
Sign: +
Exponent: -127
Mantisse: 00000000010000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 10
Float: FLT_MIN/2^11: 5,739719E-42
Sign: +
Exponent: -127
Mantisse: 00000000001000000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 11
Float: FLT_MIN/2^12: 2,869859E-42
Sign: +
Exponent: -127
Mantisse: 00000000000100000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 12
Float: FLT_MIN/2^13: 1,43493E-42
Sign: +
Exponent: -127
Mantisse: 00000000000010000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 13
Float: FLT_MIN/2^14: 7,174648E-43
Sign: +
Exponent: -127
Mantisse: 00000000000001000000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 14
Float: FLT_MIN/2^15: 3,587324E-43
Sign: +
Exponent: -127
Mantisse: 00000000000000100000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 15
Float: FLT_MIN/2^16: 1,793662E-43
Sign: +
Exponent: -127
Mantisse: 00000000000000010000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 16
Float: FLT_MIN/2^17: 8,96831E-44
Sign: +
Exponent: -127
Mantisse: 00000000000000001000000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 17
Float: FLT_MIN/2^18: 4,484155E-44
Sign: +
Exponent: -127
Mantisse: 00000000000000000100000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 18
Float: FLT_MIN/2^19: 2,242078E-44
Sign: +
Exponent: -127
Mantisse: 00000000000000000010000
Type: GSL_IEEE_TYPE_DENORMAL
Run: 19
Float: FLT_MIN/2^20: 1,121039E-44
Sign: +
Exponent: -127
Mantisse: 00000000000000000001000
Type: GSL_IEEE_TYPE_DENORMAL

Run: 20
Float: FLT_MIN/2^21: 5,605194E-45
Sign: +
Exponent: -127
Mantisse: 00000000000000000000100
Type: GSL_IEEE_TYPE_DENORMAL

Run: 21
Float: FLT_MIN/2^22: 2,802597E-45
Sign: +
Exponent: -127
Mantisse: 00000000000000000000010
Type: GSL_IEEE_TYPE_DENORMAL

Run: 22
Float: FLT_MIN/2^23: 1,401298E-45
Sign: +
Exponent: -127
Mantisse: 00000000000000000000001
Type: GSL_IEEE_TYPE_DENORMAL



On Wed, Nov 14, 2012 at 4:21 PM, Stephan Petzchen <
address@hidden> wrote:

>
> Hi,
>
> I am checking gsl for IEEE denormal resp. subnormal numbers. I took the
> test case from gsl in: iee-utils/test.c (185).
>
> Unfortunately I do not get the expected results:
> 1. Exponent is -126 instead -127
> 2. Mantisse should be: 10000000000000000000000 instead of
> 00000000000000000000000
> 3. IEEE Type is Normal instead of denormal.
>
>
>
> *Expected output:*
> Run: 0
> Float: FLT_MIN/2^1
> Sign: +
> Exponent: -127
> Mantisse: 10000000000000000000000
> Type: GSL_IEEE_TYPE_DENORMAL
>
> *Actual output:*
> Run: 0
> Float: FLT_MIN/2^1: 5,877472E-39
> Sign: +
> Exponent: -126
> Mantisse: 00000000000000000000000
> Type: GSL_IEEE_TYPE_NORMAL
>
>
> Maybe someone can give me a hint whats going wrong here.
> I am working with the mono framework/C# and gsl 1.15. Testcases for normal
> numbers passed as expected.
>
> Thanks in advance.
>
> best,
> Stephan
>
> Here is my code:
>
> public const float  GSL_FLT_MIN       = 1.1754943508222875e-38f       ;
>
> float f = (float)gsl_machine.GSL_FLT_MIN;
> char[] cmantissa = new
> char[]{'1','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
>  string mantissa="10000000000000000000000";
> gsl_ieee_float_rep r = new gsl_ieee_float_rep ();
>
> for (int i = 0; i < 23; i++) {
> float x = (float)(f / (float)System.Math.Pow (2.0f, 1f + (float) i));
>  cmantissa[i] = '1';
> mantissa=new String(cmantissa);
>
>  gsl_ieee_utils.gsl_ieee_float_to_rep (&f, ref r);
>
> Assert.AreEqual (0, r.sign);
>  Assert.AreEqual (-127, r.exponent);
> Assert.AreEqual (mantissa, r.mantissa);
>  Assert.AreEqual ((int)GSL_IEEE_TYPE.GSL_IEEE_TYPE_DENORMAL, r.type);
>
>
>
>


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