Re: distributed computation of median

2017-04-18 Thread pavan adukuri
Do you know of any python implementation for the same? thanks pavan On 4/17/17, 9:54 AM, svjk24 wrote: Hello, Is there any interest in an efficient distributed computation of the median algorithm? A google search pulls some stackoverflow discussion but it would be good to have one provided.

Re: distributed computation of median

2017-04-17 Thread Koert Kuipers
Also q-tree is implemented in algebird, not hard to get it going in spark. That is another probabilistic data structure that is useful for this. On Apr 17, 2017 11:27, "Jason White" wrote: > Have you looked at t-digests? > > Calculating percentiles (including medians) is something that is inhere

Re: distributed computation of median

2017-04-17 Thread Reynold Xin
The DataFrame API includes an approximate quartile implementation. If you ask for quantile 0.5, you will get approximate median. On Sun, Apr 16, 2017 at 9:24 PM svjk24 wrote: > Hello, > Is there any interest in an efficient distributed computation of the > median algorithm? > A google search

Re: distributed computation of median

2017-04-17 Thread Jason White
Have you looked at t-digests? Calculating percentiles (including medians) is something that is inherently difficult/inefficient to do in a distributed system. T-digests provide a useful probabilistic structure to allow you to compute any percentile with a known (and tunable) margin of error. http