Re: [Discuss-gnuradio] VOLK: fast way to log10()?

[Dennis Glatting]

On Wed, 2015-09-16 at 00:32 -0400, Brian Padalino wrote:
> On a side note, this is extremely impressive and I wish I knew about
> it sooner:
> 
>   https://software.intel.com/sites/landingpage/IntrinsicsGuide/
> 
> There's a few different log10_ps (packed single) functions in there.
> 

That's really interesting Thanks. I recently purchased two MICs for
learning but still awaiting parts for my server. I see KNC listed.


> Brian
> 
> On Wed, Sep 16, 2015 at 12:24 AM, Dennis Glatting <address@hidden>
> wrote:
> > On Tue, 2015-09-15 at 23:35 -0400, Marcus D. Leech wrote:
> > > On 09/15/2015 11:15 PM, Dennis Glatting wrote:
> > > > With the VOLK library, is there a way to compute the log10() of
> > > > each
> > > > 32f in a buffer?
> > > > 
> > > > That is:
> > > > 
> > > >   for( int i = 0; i < num; ++i )
> > > >     buf[i] = std::log10( buf[i]);
> > > > 
> > > > I only see log2() in the library but don't know if there is an
> > > > easy
> > > > way
> > > > to compute log10().
> > > > 
> > > > 
> > > > Thanks.
> > > Define "fast".
> > > 
> > 
> > Faster than the code fragment above.
> > 
> > I see log2(), pow(), sin(), and other kernels in the library and
> > /assumed/ there must be some way of log10() if only through a
> > combination of kernel calls.
> > 
> > 
> > > Ordinarily, one does a log10 to convert into engineering units at
> > > the
> > > back of, for example, a power-measurement chain.
> > > 
> > > There's usually no reason to do that in the middle of a flow
> > > -graph,
> > > where things can stay in linear units.
> > > 
> > 
> > 1) Working with VOLK to learn VOLK.
> > 2) Having fun with vectors.
> > 3) Generating power data points for plotting across a selected
> >    set of samples.
> > 
> > 
> > > 
> > > 
> > > _______________________________________________
> > > Discuss-gnuradio mailing list
> > > address@hidden
> > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> > 
> > _______________________________________________
> > Discuss-gnuradio mailing list
> > address@hidden
> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio