ARROW-11193: [Java][Documentation] Add Java ListVector Documentation #9142
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Thanks for opening a pull request! Could you open an issue for this pull request on JIRA? Then could you also rename pull request title in the following format? See also: |
jjbskir
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docs/source/java/vector.rst
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| A :class:`ListVector` is a vector that holds a list of values for each index. Working with one you need to handle the same steps as mentioned above (create > allocate > mutate > set value count > access > clear), but the details of how you accomplish this are slightly different since you need to both create the vector and set the list of values for each index. | ||
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| For example, the code below shows how to build a :class:`ListVector` of int's using the writer :class:`UnionListWriter`. We build a vector from 0 to 10 and each index contains a list with increasing values [[0, 0, 0, 0, 0], [0, 1, 2, 3, 4], [0, 2, 4, 6, 8], …, [0, 9, 18, 27, 36]]. |
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Hey, thanks for the catch, I will update the PR.
| A :class:`ListVector` is a vector that holds a list of values for each index. Working with one you need to handle the same steps as mentioned above (create > allocate > mutate > set value count > access > clear), but the details of how you accomplish this are slightly different since you need to both create the vector and set the list of values for each index. | ||
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| For example, the code below shows how to build a :class:`ListVector` of int's using the writer :class:`UnionListWriter`. We build a vector from 0 to 9 and each index contains a list with increasing values [[0, 0, 0, 0, 0], [0, 1, 2, 3, 4], [0, 2, 4, 6, 8], …, [0, 9, 18, 27, 36]]. | ||
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The values of each index can be in arbitrary orders. This example may confuse the readers?
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Hey yea that is a possibility. We can always write in the docs that the values can be added in arbitrary order. Or instead of using a for loop to add the values we can have some predefined arrays we want to add in that have arbitrary order like: [[1, 2, 3], [3, 2, 1], [10, 30, 20]]. Also looking at the tests for ListVector it looks like they all use ascending order.
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Sure. I see you point. It makes sense.
Maybe here we should not stress that the values are in increasing order?
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Sounds good I will update the docs to reflect this.
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Merging. Thanks for your effort @jjbskir |
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Hey @liyafan82 wanted to check how often do you guys rebuild the docs for this page? https://arrow.apache.org/docs/java/ |
@jjbskir The website should be updated after the next release. |
Added documentation for the Java [ListVector](https://arrow.apache.org/docs/java/reference/org/apache/arrow/vector/complex/ListVector.html) class. I found using it to be difficult with out any concrete examples. Closes apache#9142 from jjbskir/patch-1 Authored-by: Jeremy <jjbskir@gmail.com> Signed-off-by: liyafan82 <fan_li_ya@foxmail.com>
Added documentation for the Java ListVector class. I found using it to be difficult with out any concrete examples.