GH-35550: [MATLAB] Add public toMATLAB method to arrow.array.Array for converting to MATLAB types

[kevingurney]

Rationale for this change

In order to allow clients to write generic code for different concrete arrow.array.Array subclasses in MATLAB, it would be helpful to have one generic toMATLAB method. toMATLAB would convert the arrow.array.Array into a corresponding MATLAB type.

For example, arrow.array.Float64Array would be converted to a MATLAB double array.

>> doubleMatlabArray = toMATLAB(float64ArrowArray) % Convert the arrow.array.Float64Array to a MATLAB double array

What changes are included in this PR?

1. Added a public toMATLAB method to the arrow.array.Array superclass.

Example of using toMATLAB on an arrow.array.Float64Array:

>> arrowArray = arrow.array.Float64Array(1:10)

arrowArray = 

[
  1,
  2,
  3,
  4,
  5,
  6,
  7,
  8,
  9,
  10
]
>> matlabArray = toMATLAB(arrowArray)

matlabArray =

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10

>> class(matlabArray)

ans =

    'double'

Are these changes tested?

1. Yes, we added tests for toMATLAB to tFloat32Array.m and tFloat64Array.m.
2. This was qualified on a Debian 11 machine.

Future Directions

1. Move the toMATLAB tests to the shared test utility class (i.e. [MATLAB] Create shared test class utility for numeric arrays. #35537).

Notes

1. Thanks to @sgilmore10 for her help with this pull request!

• Closes: [MATLAB] Add public toMATLAB method to arrow.array.Array for converting to MATLAB types #35550

[github-actions]

Thanks for opening a pull request!

If this is not a minor PR. Could you open an issue for this pull request on GitHub? https://github.com/apache/arrow/issues/new/choose

Opening GitHub issues ahead of time contributes to the Openness of the Apache Arrow project.

Then could you also rename the pull request title in the following format?

GH-${GITHUB_ISSUE_ID}: [${COMPONENT}] ${SUMMARY}

or

MINOR: [${COMPONENT}] ${SUMMARY}

In the case of PARQUET issues on JIRA the title also supports:

PARQUET-${JIRA_ISSUE_ID}: [${COMPONENT}] ${SUMMARY}

See also:

• Other pull requests
• Contribution Guidelines - How to contribute patches

[github-actions]

• Closes: [MATLAB] Add public toMATLAB method to arrow.array.Array for converting to MATLAB types #35550

[kou]

I'm not familiar with MATLAB API but is it natural that ToString uses T and toMATLAB uses t?

[sgilmore10]

Hi @kou, That's a mistake on our part. ToString should be toString. Typically, we use lower camel case for MATLAB method names. Thanks for catching this!

[sgilmore10]

1. Changed ToString() to toString().
2. Also renamed the c++ method Length() to length(). However, since this Length is a property on the MATLAB arrow.array.Array class, I left the property name alone. In MATLAB, property names are typically upper camel case.

[kou]

+1

[ursabot]

Benchmark runs are scheduled for baseline = 505a2e4 and contender = 88339cd. 88339cd is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Finished ⬇️0.29% ⬆️0.09%] test-mac-arm
[Finished ⬇️1.02% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.27% ⬆️0.06%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 88339cd8 ec2-t3-xlarge-us-east-2
[Finished] 88339cd8 test-mac-arm
[Finished] 88339cd8 ursa-i9-9960x
[Finished] 88339cd8 ursa-thinkcentre-m75q
[Finished] 505a2e45 ec2-t3-xlarge-us-east-2
[Finished] 505a2e45 test-mac-arm
[Finished] 505a2e45 ursa-i9-9960x
[Finished] 505a2e45 ursa-thinkcentre-m75q
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java

[ursabot]

['Python', 'R'] benchmarks have high level of regressions.
ursa-i9-9960x