Matrix sum along a dimension is defined to return a `MathScalarType`, but might return higher dimension · josdejong/mathjs#3202

(5 comments) (0 reactions) (1 assignee)JavaScript (13,832 stars) (1,298 forks)batch import

bughelp wantedtypescript

説明

Describe the bug When summing over an axis of a matrix, we always lose just one dimension. If the matrix is 2D, we'll get a 1D array. If the matrix is 3D, we'll get a 2D matrix. What happens now, is that math.sum declares that it returns a MathScalarType, instead of optionally returning a matrix.

To Reproduce

const mat = math.matrix([[1,2,3],[4,5,6]])
console.log(math.sum(mat, 0))

> DenseMatrix { _data: [ 5, 7, 9 ], _size: [ 3 ], _datatype: undefined }

コントリビューターガイド

技術スタック: javascript
領域: api
Issue 種別: bug
難度: 3
推定時間: 1-3 hours
活動状況: blocked
明確さ: clear
前提条件: Basic JavaScript knowledgeUnderstanding of matrix operationsFamiliarity with math.js types
初心者向け度: 50
調査方針: The bug is in the type signature of the sum function in mathjs. The issue likely requires updating the return type in the TypeScript declaration file (if any) or the JSDoc comment in the source file (e.g., src/type/matrix/function/sum.js). The code currently returns the result of math.sum which may be a DenseMatrix instead of a scalar. To fix, the function should return a MathGenericType or similar that accounts for multidimensional arrays. The existing tests in the test directory may need to be updated to cover this case. No linked PRs yet; the assignee may be working on a fix.