[REEF-1663] Fix TestKMeansOnDirectRunViaFileSystem failure in AppVeyor

• Type: Sub-task
• Status: Reopened
• Priority: Minor
• Resolution: Unresolved
• Component/s: REEF.NET
• Assignee: Mariia Mykhailova
• Reporter: Mariia Mykhailova
• Created: 03/Nov/16 21:59
• Updated: 02/Aug/17 02:03

Description

O.A.R.Tests.Functional.ML.KMeans.TestKMeans.TestKMeansOnDirectRunViaFileSystem failed on AppVeyor with error

System.InvalidOperationException : The new loss 14658.95 is larger than previous loss 14658.95, while loss function must be monotonically decreasing across iterations

I doubt that the new loss was really significantly less than the previous one, since the displayed values are identical. But the test uses exact comparisons of floating-point numbers, which occasionally might produce unexpected results.

We should probably replace exact comparisons with a proper comparison function, as described here. Note that this comparison is done in two files - TestKMeans.cs and KMeansMasterTask.cs.