GH-37592: [MATLAB] Add NumRows property to arrow.tabular.RecordBatch

[kevingurney]

Rationale for this change

Currently, there is a NumColumns property on arrow.tabular.RecordBatch, but no NumRows property. It would be useful to be able to query the number of rows in a RecordBatch.

This pull request adds a NumRows property to arrow.tabular.RecordBatch to mirror the design of arrow.tabular.Table.

What changes are included in this PR?

1. Added new NumRows property to arrow.tabular.RecordBatch

Example

>> matlabTable = array2table(rand(10, 5))           

matlabTable =

  10x5 table

      Var1        Var2       Var3       Var4        Var5  
    ________    ________    _______    _______    ________

     0.76062     0.12009    0.98898    0.29974     0.42165
     0.64994     0.85116    0.71768    0.58693     0.31061
     0.33593     0.87823    0.87766    0.38206     0.45742
    0.031364      0.8336    0.71528    0.14987      0.3618
      0.5986     0.81193    0.25784    0.21073     0.76715
     0.46493     0.40281    0.39729    0.16737     0.94521
     0.18738     0.16351    0.46437    0.45545     0.40774
     0.67682      0.3577    0.94882     0.1295    0.022501
     0.29368     0.47122    0.99682    0.46011     0.34275
      0.6849    0.064717    0.89719    0.38302      0.4523

>> arrowRecordBatch = arrow.recordBatch(matlabTable);

>> arrowRecordBatch.NumRows

ans =

  int64

   10

Are these changes tested?

Yes.

1. Added NumRows test to tRecordBatch test class.
2. Updated EmptyTable test (renamed to EmptyRecordBatch) in tRecordBatch test class.
3. Added FromArraysNoInputs test to mirror the FromArraysNoInputs test in tTable test class.

Are there any user-facing changes?

Yes.

This pull request adds a new public NumRows property to the arrow.tabular.RecordBatch class. Users can query the number of rows in an arrow.tabular.RecordBatch by accessing the NumRows property.

Future Directions

1. [MATLAB] Add a common arrow.tabular.Tabular MATLAB interface #38214
2. [MATLAB] Create a superclass for tabular type MATLAB tests (i.e. for Table and RecordBatch) #38213

• Closes: [MATLAB] Add NumRows property to arrow.tabular.RecordBatch #37592

[kevingurney]

+1

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 5 benchmarking runs that have been run so far on merge-commit ef02417.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 2 possible false positives for unstable benchmarks that are known to sometimes produce them.