: Hi, I am running into a weird rounding issue on Solr 5.2.1. I have a float
: field (also tried tfloat), I am indexing 154035.26 into it (confirmed in
: the data), but at query time, I get back 154035.27 (.01 more).
: Additionally when I query for the document and include this number in the q
: parameter, it comes up with both values, .26 and .27.
Pretty sure what you are observing is just the normal consequences of IEEE
floats (as used by java) being base2 -- not every base10 decimal value
has a precise base2 representation.
Quering for 154035.27 and 154035.26 will both match the same docs, because
the String->Float parsing in both cases will produce the closest *legal*
float value, which is identical for both inputs.
If need precise decimal values in solr, you need to either use 2
ints/longs (ie num_base="154035", num_decimal="26") or use one int/long
and multiply/divide by a power of 10 corisponding to the number of
significant digits you want in the client (ie: "15403526" divide by 100)
Some good reading linked to from here...
http://perlmonks.org/?node_id=203257
And of course, if you really want to bang java against your head,
this is a classic (all of which is still appliable i believe) ...
https://people.eecs.berkeley.edu/~wkahan/JAVAhurt.pdf
-Hoss
http://www.lucidworks.com/
