Corrects interval notation in doc comment

[w3iBStime]

The random number generated by XORShiftRandom.nextDouble() is a value between zero and one, including zero but not including one. I.e., 0 <= x < 1 . I've denoted this by changing the closing square bracket to a closing parenthesis.

You can also think of trying to uniformly randomly assign items in a list to three classes 'A', 'B' and 'C'. For each item, if {randomDouble * 3.0} is between 0.000 and 0.999, it gets assigned to A. If between 1.000 and 1.999, it goes to B. If between 2.000 and 2.999 it goes to C. All three classes have the same probability of receiving the item. If it were possible for the raw random number to be exactly 1.000, then after scaling the range by multiplying times 3.0 class C would be slightly more likely to receive the item than A or B (assuming simple logic instead of more extensive/expensive logic to break ties).

Also, see the existing comment in SamplingUtils which uses the same function:

spark/core/src/main/scala/org/apache/spark/util/random/SamplingUtils.scala

Line 62 in 79f5f28

// below is a random long chosen uniformly from [0,l)

https://en.wikipedia.org/wiki/Interval_(mathematics)

What changes were proposed in this pull request?

A small notation correction in some documenting comments

How was this patch tested?

N/A documentation only.

[AmplabJenkins]

Can one of the admins verify this patch?

[srowen]

That's fine, can you look for other instances?

[w3iBStime]

I don't have a local clone of the code--just used the GitHub web UI for a small change. Unfortunately, it doesn't look like GitHub can search for "1.0]" .

[srowen]

@w3iBStime the Python and R docs need to change too if this changes, as does RandomDataGenerator. There are several instances of this. If you can make the change with a proper git clone, go for it.

[srowen]

Ping @w3iBStime can you update this or close?