As suggested by Micah, there are some problems with the common interface for numeric types: 1. corner cases for transforming special floating point values, like NaN, inf, etc. 2. loss of precision when transforming long to double.
Instead, we provide a common interface for float4 & float8 values. The purpose is similar, to reduce unnecessary branch/swtich statements in the code. Please take a look https://issues.apache.org/jira/browse/ARROW-6247 Best, Liya Fan On Thu, Aug 15, 2019 at 1:41 PM Fan Liya <liya.fa...@gmail.com> wrote: > Hi Micah, > > Thanks for the good points. > I agree with you that we should improve the efficiency of algorithms. > > This is related to another improvement: reduce the if/switch statements in > the code. > > To account for the edge cases, can we remove the set methods, and leaving > only the get method? > This is because for some scenarios, we have vectors that can either be int > vectors or float vectors. > > The common interface for float4 and float8 sounds good. Let's do it in > another issue. > > Best, > Liya FAn > > On Thu, Aug 15, 2019 at 12:49 PM Micah Kornfield <emkornfi...@gmail.com> > wrote: > >> Hi Liya Fan, >> I'm not sure if this is a good idea. First, floating point operations >> have >> more edge cases than integer arithmetic (e.g. dealing with NaNs). Second, >> and I apologize that I've been remiss in thinking this through on reviews, >> but I think we should be thinking about how to make algorithms/operations >> as efficient as possible. In this regards putting everything behind an >> interface prevents the JVM JIT from inlining them effectively. >> >> It might not be a bad idea to have a have a common interface for just the >> Float4 and Float8 vectors, but I'd like to get other peoples thoughts on >> this. >> >> Thanks, >> Micah >> >> On Wed, Aug 14, 2019 at 7:26 PM Fan Liya <liya.fa...@gmail.com> wrote: >> >> > Dear all, >> > >> > >> > >> > We want to provide an interface for all vectors with numeric types >> (small >> > int, float4, float8, etc). This interface will make it convenient for >> many >> > operations on a vector, like average, sum, variance, etc. With this >> > interface, the client code will be greatly simplified, with many >> > branches/switch removed. >> > >> > >> > >> > The design is similar to BaseIntVector (the interface for all integer >> > vectors). We provide 3 methods for setting & getting numeric values: >> > >> > setWithPossibleRounding >> > >> > setSafeWithPossibleRounding >> > >> > getValueAsDouble >> > >> > >> > >> > Please give some comments. Thanks a lot. >> > >> > >> > >> > Best, >> > >> > Liya Fan >> > >> >
