By the way, with a bit of approximation and a little acceptance for errors in corner cases, log2 of a IEEE-754 float is simply it's exponent + log2(mantissa), with the later potentially being implementable using lookup tables. Also, VOLK does have a log2, kernel, volk_32f_log2_32f
Best regards, Marcus On 16.09.2015 06:50, Brian Padalino wrote: > On Wed, Sep 16, 2015 at 12:24 AM, Dennis Glatting <gnura...@pki2.com> wrote: >> 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. > Lastly, another alternative, if you wanted to utilize what is already > there in VOLK, if you wanted to do something like 10*log10(x), you can > also think of it as 10*log2(x)/log2(10) - rewritten to put the > constants together - 10*log2(10)*log2(x), where 10*log2(10) is > 3.01029995664. > > So convert a vector of floats into log2 then multiply a vector by a > const that is equal to 10*log2(10) to get them to their final value. > Not as efficient, potentially, but still an option if you want to > learn VOLK. > > Brian > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
