Re: [boost] different matrix library?

Subject: Re: [boost] different matrix library?
From: Edward Grace (ej.grace_at_[hidden])
Date: 2009-08-18 15:41:17

On 18 Aug 2009, at 19:52, joel wrote:

> Edward Grace wrote:
>> It means what it says, for the two functions you are timing there is
>> no measurable difference in execution time that cannot be  
>> explained by
>> chance.  So, if you think A is faster than B or B is faster than A,
>> you are mistaken.
>>
>> The final figure for example, -5.22 --- +4.15, indicates that with a
>> 95% chance the speedup of A relative to B lies between those
>> extremes.  Since these extremes clearly include zero you can't say
>> there is a speedup.  The best point estimate of the speedup is 0.053%
>> (naff all!).
> This means A and B have the same execution time most of the time  
> then ?

No, it's more subtle than that.  Almost all of the time there will be  
a difference between A and B, however this difference is just 'noise'  
around zero.

In order for there to be a meaningful difference the natural random  
variations of the differences should be significantly different from  
zero.

-ed