On 11/20/2017 07:52 AM, Marcus Müller wrote:
> Hi Folks,
> 
> I was about to commit a PR VOLKizing nlog10 [1], but it struck me that
> my processor (imho, correctly) says that log(0) == nan and log(-10) ==
> nan.
> 
> Whereas the old nlog10 test case asserts that it's log_10(x<=0) == -18.

It would have to be complex

    y=log10(-.00000000000000000001)
    y=-18 + 1.3644i

For x real, then the limit as x approaches 0 from the positive side is
-infinity.

For x real from the negative side it's undefined since for any y, 10**y > 0.

-- Cinaed


> 
> So, am I allowed to break that assertion for the greater mathematical
> appropriateness and speed?
> 
> Best regards,
> Marcus
> 
> [1]
> https://github.com/marcusmueller/gnuradio/tree/blocks_volkized_nlog10
> 
> 
> 
> _______________________________________________
> 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

Reply via email to