Aleksei Smirnov

ARROW-17330: [C#] Extend ArrowBuffer.BitmapBuilder to improve performance of array concatenation

3

Extend ArrowBuffer.BitmapBuilder with Append method overloaded with ReadOnlySpan parameter. This allows to add validity bits to the builder more efficiently (especially for cases when initial validity bits are added to...

As it was mentioned in #6642 DataFrame has a lot of boilerplate code like: ``` DataFrameBuffer resultMutableBuffer = DataFrameBuffer.GetMutableBuffer(resultBuffer); resultContainer.Buffers[b] = resultMutableBuffer; Span resultSpan = resultMutableBuffer.Span; DataFrameBuffer resultMutableNullBitMapBuffer = DataFrameBuffer.GetMutableBuffer(resultContainer.NullBitMapBuffers[b]);...

[Proposal] DataFrame Arithmetic and Computation API

2

## Background and motivation Current arithmetic and computation API of the DataFrame is inconsistent and quite slow in scenarios where columns of different types are involved as each column casting...

Extend dataframe orderby method to allow defining preferred position for null values

2

Fixes #7102

Implement DataFrameColumn Apply and DropNulls methods

2

Fixes #7107 as was asked in https://github.com/dotnet/machinelearning/issues/6144#issuecomment-2018430389 Additionaly: 1) Fix incorrect IsNumeric method 2) Fix error FillNulls crashes with NotImplemented exception on DataFrame with VBufferDataFrameColumn 3) Improve speed and redesign...

Test to reproduce: ```cs public void TestApplyMethod() { PrimitiveDataFrameColumn column = new PrimitiveDataFrameColumn("Byte1", int.MaxValue / 2 - 1); PrimitiveDataFrameColumn newColumn = column.Apply(x => (double?)x); } ``` Root cause is in...

DataFrame OrderBy method should always place null values at the bottom of the list (after not nullable values) independently of sorting (ascending or descending). This is how Python does and...

Use new System.Numerics.Tensors library for DataFrame arithmetic operations (.net8)

2

Use new System.Numerics.Tensors library for DataFrame arithmetic operations (.net8) Fixes #7178 The aim of this PR to use new library for DataFrame arithmetic operations instead of custom implemtation. At the...

Use new System.Numerics.Tensors library for DataFrame arithmetic operations instead of custom implementation