On 05/17/2011 01:26 PM, Pirogov Eugene wrote:
> I'm experience the loss of speed in NArrays. Did you guys tried benching
> a simple access to an element in NArray?
>
> My benches show dramatical slowdown comparing to a Ruby built-in Array.
> I already filled an issue here:
> https://github.com/masa16/narray/issues/8.
>

It's too simple a benchmark to demonstrate the efficiency of narray. 
What it's measuring is access time from ruby. For the first two cases, 
the number in the ruby array is a fixnum (shifted by one bit and or-ed 
with 0x01) that can simply be returned with no modification, as a 32 or 
64 bit VALUE (ruby's basic data type). In the third case, the number is 
stored as an 8 bit signed int, which has to be converted to VALUE by 
sign extending, shifting, and or-ing.

As soon as you start measuring operations whose inputs and outputs are 
both NArrays (especially large ones), you'll see the speed...