Re: [PATCH 2/3] winex11: Implement TINN algorithm. (try 3)

[Dmitry Timoshkov]

"Vitaly Budovski"  wrote:
> +struct tinn
> +{
> - /* Pointer to an element in the list. */
> - const RGBQUAD *data;
> - /* Distance from the reference element. */
> - float distance;
>
> +};

Vitaly, why do you keep resending the same patch which uses float
values internally? Again, float neither doesn't allow you to process
larger values, nor is acceptable for speed or adds more flexibility.

[PATCH 2/3] winex11: Implement TINN algorithm. (try 3)

[Vitaly Budovski]

Dmitry Timoshkov wrote:
> "Vitaly Budovski"  wrote:
> > +struct tinn
> > +{
> > - /* Pointer to an element in the list. */
> > - const RGBQUAD *data;
> > - /* Distance from the reference element. */
> > - float distance;
> >
> > +};
>
> Vitaly, why do you keep resending the same patch which uses float
> values internally? Again, float neither doesn't allow you to process
> larger values, nor is acceptable for speed or adds more flexibility.

I actually discussed this with Alexandre on irc and he said that it was 
okay to leave it like that. Please show me how an unsigned int can 
represent values greater than 2^32. This is why a float is used.

[PATCH 2/3] winex11: Implement TINN algorithm. (try 3)

[Dmitry Timoshkov]

"Vitaly Budovski"  wrote:
> Please show me how an unsigned int can 
> represent values greater than 2^32. This is why a float is used.

Of course int can't, but neither float can. Perhaps you confuse it with
double?

[PATCH 2/3] winex11: Implement TINN algorithm. (try 3)

[Vitaly Budovski]

Dmitry Timoshkov wrote:
> "Vitaly Budovski"  wrote:
> > Please show me how an unsigned int can represent values greater than 
> > 2^32. This is why a float is used.
>
> Of course int can't, but neither float can. Perhaps you confuse it with
> double?

I'm pretty sure I'm not confusing it with double.
http://steve.hollasch.net/cgindex/coding/ieeefloat.html
http://en.wikipedia.org/wiki/IEEE_754#Single-precision_32_bit

[PATCH 2/3] winex11: Implement TINN algorithm. (try 3)

[Mike Schaadt]

An int value can be more precise then a float can, however a float can
hold bigger numbers.  It's the difference between having a 24 bit
fraction with 8 bits of exponent and 1 of sign vs 31/32 bits of
fraction data without exponent.  Plus, integer operations are faster
then floating point operations, even if just margionably.

On 5/9/07, Vitaly Budovski  wrote:
> Dmitry Timoshkov wrote:
> > "Vitaly Budovski"  wrote:
> > > Please show me how an unsigned int can represent values greater than
> > > 2^32. This is why a float is used.
> >
> > Of course int can't, but neither float can. Perhaps you confuse it with
> > double?
>
> I'm pretty sure I'm not confusing it with double.
> http://steve.hollasch.net/cgindex/coding/ieeefloat.html
> http://en.wikipedia.org/wiki/IEEE_754#Single-precision_32_bit

[PATCH 2/3] winex11: Implement TINN algorithm. (try 3)

[Rolf Kalbermatter]

Dmitry Timoshkov [mailto:[e-mail]] wrote:
> "Vitaly Budovski"  wrote:
> > Please show me how an unsigned int can represent values greater than 
> > 2^32. This is why a float is used.
>
> Of course int can't, but neither float can. Perhaps you confuse it with

double?

I think float can represent integers larger than 2^32 but it will be not
anymore
fully accurate. In fact it will start getting inaccurate in representing
every
possible integer at around 2^22. But that does not mean that it can't
represent
2^40 approximately. The maximum decimal range of a float is around +-4 * 10
^ 38
compared to 4 * 10 ^ 9 for an unsigned 32 bit integer.

So if full integer accuracy is not a concern, which I think isn't in this
case,
floats definitely have a range advantage over 32 bit integers. Even 64 bit
integers can't cover that range although they might have a large enough
range
for this problem.

Rolf Kalbermatter