[Java] Floating point vectors should do an approximate comparison in integration tests

[asfimport]

Floating point precision rears its ugly head:

Incompatible files
Different values in column:
Field{name=float64_nullable, type=FloatingPoint{2}, children=[], layout=TypeLayout{[{width=1,type=VALIDITY}, {width=64,type=DATA}]}} at index 1: 912.4140000000002 != 912.414
10:23:45.863 [main] ERROR org.apache.arrow.tools.Integration - Incompatible files
java.lang.IllegalArgumentException: Different values in column:
Field{name=float64_nullable, type=FloatingPoint{2}, children=[], layout=TypeLayout{[{width=1,type=VALIDITY}, {width=64,type=DATA}]}} at index 1: 912.4140000000002 != 912.414

Reporter: Wes McKinney / @wesm
Assignee: Julien Le Dem / @julienledem

PRs and other links:

• PR

_{Note: This issue was originally created as ARROW-401. Please see the migration documentation for further details.}

[asfimport]

Julien Le Dem / @julienledem:
PR: #223

[asfimport]

Jacques Nadeau / @jacques-n:
This is what I've used elsewhere before:

    boolean evaluateEquality(Float f1, Float f2) {
      if(f1.isNaN()){
        return f2.isNaN();
      }

      if(f1.isInfinite()){
        return f2.isInfinite();
      }

      if ((f1 + f2) / 2 != 0) {
        return Math.abs(f1 - f2) / ((f1 + f2) / 2) < 1.0E-6;
      } else {
        return !(f1 != 0);
      }
    }

    boolean evaluateEquality(Double f1, Double f2) {
      if(f1.isNaN()){
        return f2.isNaN();
      }

      if(f1.isInfinite()){
        return f2.isInfinite();
      }

      if ((f1 + f2) / 2 != 0) {
        return Math.abs(f1 - f2) / ((f1 + f2) / 2) < 1.0E-12;
      } else {
        return !(f1 != 0);
      }
    }
  }

[asfimport]

Julien Le Dem / @julienledem:
what is the source for those?
Any details on why = 0) as opposed to f1 == 0 for example?

[asfimport]

Jacques Nadeau / @jacques-n:
I wrote it based initially on the code here: https://github.com/mapr/drill-test-framework/blob/master/framework/src/main/java/org/apache/drill/test/framework/ColumnList.java#L115

Don't remember offhand the f1 != 0. What are the rules about NaN and Infinite in the case of a floating point negation?

[asfimport]

Julien Le Dem / @julienledem:
this method will return early if f1 is NAN or infinite so there's no special case here.

[asfimport]

Jacques Nadeau / @jacques-n:
good point :D

[asfimport]

Julien Le Dem / @julienledem:
Issue resolved by pull request 223
#223