[MINOR][Documentation] Fix some minor descriptions in functions consistently with expressions

[HyukjinKwon]

What changes were proposed in this pull request?

This PR proposes to improve documentation and fix some descriptions equivalent to several minor fixes identified in #15677

Also, this suggests to change Note: and NOTE: to .. note:: consistently with the others which marks up pretty.

How was this patch tested?

Jenkins tests and manually.

For PySpark, Note: and NOTE: to .. note:: make the document as below:

From

To

[HyukjinKwon]

It seems something wrongly gone in my local so I can't run cran-check for SparkR in my local. Please let me run this via Jenkins.

[HyukjinKwon]

Please let me cc @felixcheung and @srowen though if you don't mind.

[HyukjinKwon]

Oh, actually, it seems I should fix the ones in functions.scala too.

[SparkQA]

Test build #68124 has finished for PR 15765 at commit c8fafbe.

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

[HyukjinKwon]

This one was missed in 02f2031 and a08463b

[SparkQA]

Test build #68125 has finished for PR 15765 at commit 4d8e829.

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

[HyukjinKwon]

It seems the newly added test seems too flaky. the specific test seems often failed. I saw this failure in series randomized aggregation test - [typed, with partial + safe] - with grouping keys - with non-empty input cc @liancheng

[1]https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/68125/consoleFull
[2]https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/68112/consoleFull
[3]https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/68119/consoleFull
[4]https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/68121/consoleFull

[HyukjinKwon]

retest this please

[SparkQA]

Test build #68126 has finished for PR 15765 at commit 9b5b8eb.

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

[SparkQA]

Test build #68128 has finished for PR 15765 at commit 9b5b8eb.

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

[SparkQA]

Test build #3414 has finished for PR 15765 at commit 9b5b8eb.

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

[felixcheung]

changes LGTM. thanks.
to nit pick, I find this "(Signed) shift the given value numBits right." confusing. Perhaps we should clarify this across all doc?

[srowen]

How would you write it? we do need to specify that it's a signed shift.

[felixcheung]

hmm, like "shift the signed value numBits to the right"?

[HyukjinKwon]

Ah, IMHO, it seems both are fine but actually it seems there is an unsigned shift one which is described as..

Unsigned shift the given value numBits right.

So.. if any of you does not feel strongly which one is better, I hope I could leave as it is because it seems at least consistent.

(Signed) shift the given value numBits right.

[felixcheung]

I think both sound odd, but it's a nit

[srowen]

It's not a shift of a signed value, but a 'signed' shift, meaning one that preserves the sign bit. I recognize the terms "unsigned shift" and "signed shift", FWIW.

[felixcheung]

Sure then.
Merged to master/branch-2.1

[HyukjinKwon]

Thank you both!