How to get mantissa?

[Peng Yu]

Hi,

I'm wondering if there is any standard function that computes mantissa
a floating point number. I could use x - floor(x), suppose x is a
floating number. But this involves an additional floating point
operation (minus).

Thanks,
Peng

 

[Anarki]

Hi,

I'm wondering if there is any standard function that computes mantissa
a floating point number. I could use x - floor(x), suppose x is a
floating number. But this involves an additional floating point
operation (minus).

Thanks,
Peng

http://steve.hollasch.net/cgindex/coding/ieeefloat.html

Once you read that page u get the idea of bit structure of a floating
point number then use masking technique using bitwise operators and
the required result u need. This way i believe it will be more faster
than the method u trying to use(x - floor(x)).

 

[James Kanze]

I'm wondering if there is any standard function that computes
mantissa a floating point number. I could use x - floor(x),
suppose x is a floating number. But this involves an
additional floating point operation (minus).

I'm not sure what you mean by the mantissa, since the expression
you give doesn't correspond to the usual definition. Anyway,
depending on what you really want, you might want to consider
frexp or modf.