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Project Support Forums => HLA Forum => Topic started by: Xor Stance on February 27, 2005, 02:46:26 AM

Title: What is mantissa bits?
Post by: Xor Stance on February 27, 2005, 02:46:26 AM
I don't know that and I don't think I had hear about that, but I do know algrebaic mathematic.
Title: Re: What is mantissa bits?
Post by: rea on February 27, 2005, 03:37:35 AM
 123.456

123 is the significand and 456 is the mantissa :). (If Im not wrong) [exponent 0]

also it can be converted to 1.23456E-2

Here the mantissa will be 23456 and the significand 1 with a exponent of -2


a binary nuber is exactly the same ;).

1001010101.1111010101
1001010101 significand
1111010101 mantissa

1.001010101[.]1111010101E-1001
1.0010101011111010101E-1001

This is a normalized binary number :)
Title: Re: What is mantissa bits?
Post by: Xor Stance on February 27, 2005, 03:53:34 AM
Thank you I understand right now. In spanish I think it was:  :green "punto decimal" or "numero entero" = "decimal dot" & "full number".
                   >.<
                                     
  ______________________
             |_|       |_|
:wink
Title: Re: What is mantissa bits?
Post by: RuiLoureiro on May 20, 2005, 09:25:55 PM
Quote from: rea on February 27, 2005, 03:37:35 AM
123.456

also it can be converted to 1.23456E-2
Here the mantissa will be 23456 and the significand 1 with a exponent of -2

Hey rea,
             the sign is + [1.2345E + 2 ] imply significand 1 with a exponent of +2
Title: Re: What is mantissa bits?
Post by: rea on May 20, 2005, 09:32:28 PM
ops :), ya that is  :toothy
Title: Re: What is mantissa bits?
Post by: raymond on May 21, 2005, 03:08:43 AM
The term mantissa is normally used with logarithms. For example, the logarithm base 10 of 5.4321 is 0.73496775631, while the logarithm of 5432.1 would be 3.73496775631. In both cases, the mantissa is the same and represents the decimal value with an integer between 1 and 10.

The term is also used with the floating point format. The number is kept in binary as you would keep a decimal number in scientific notation. Because the first digit must necessarily be a 1, it is only assumed to be there for the REAL4 and REAL8 formats, and only the decimal bits are retained and called the mantissa of the floating point number. (For the REAL10 format, the "integer" 1 is physically present in the 64-bit "mantissa".)

Hope it doesn't add to the confusion. :wink

Raymond
Title: Re: What is mantissa bits?
Post by: RuiLoureiro on May 26, 2005, 10:47:41 AM
Raymond,
      About the term «mantissa», as far as i know and supported by my bibliography, it depends the author. Some authors say the term "is mathematically inaccurate".
«Significand» is the term that was used in the IEEE standard. But, in my opinion it is irrelevant.

Hope it doesn't add to the confusion
Regards