[SPARK-8479] [MLlib] Add numNonzeros and numActives to linalg.Matrices

[MechCoder]

Matrices allow zeros to be stored in values. Sometimes a method is handy to check if the numNonZeros are same as number of Active values.

[SparkQA]

Test build #35267 has finished for PR 6904 at commit b421696.

• This patch fails MiMa tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #35282 has finished for PR 6904 at commit d4741cf.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[mengxr]

Should it be "MissingMethodProblem" instead?

[MechCoder]

@mengxr Sorry about that. Btw, when is a foreach preferred as compared to a while loop.

[SparkQA]

Test build #35286 has finished for PR 6904 at commit c0259fc.

• This patch fails MiMa tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #35291 has finished for PR 6904 at commit f3127f5.

• This patch fails MiMa tests.
• This patch merges cleanly.
• This patch adds no public classes.

[MechCoder]

ping @srowen Could you please help me figure out the compatibility problems here? I've added it to the filters but it does not seem to work.

[srowen]

Can this not be values.count(_ != 0)?

[srowen]

I think the failure is indeed because you're adding methods to a trait, but it's a sealed trait, so probably fine to override. I think you put it in the wrong place? it shoudl go under 1.5

[SparkQA]

Test build #36277 has finished for PR 6904 at commit 71b951d.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #36278 has finished for PR 6904 at commit e2390f5.

• This patch fails MiMa tests.
• This patch merges cleanly.
• This patch adds no public classes.

[MechCoder]

Thanks for the comments but Vector is a sealed trait as well but that seems to work fine.

[mengxr]

MiMa doesn't know it. So we still need to add the exclusion rules explicitly, otherwise it won't pass Jenkins.

[MechCoder]

Have I done it correctly?

[SparkQA]

Test build #36288 has finished for PR 6904 at commit 252c6b7.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[mengxr]

LGTM. Merged into master. Thanks!