scalanlp/breeze

Missing Transpose(DenseVector)*CSC operation?

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#715 opened on Jun 20, 2018

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 (1 comment) (2 reactions) (0 assignees)Scala (3,453 stars) (690 forks)batch import
good first issue

Description

Hello!

I have a CSC sparse matrix and a DenseVector. I want to do the operation transpose(DenseVector)*CSCMatrix, which should yield a Transpose(DenseVector). As far as I could see, this method is not implemented. This seems implemented for transpose(SparseVector)CSCMatrix (method canMulSVt_CSC_eq_SVt in CSCMatrixOps.scala ), but I could not find a DenseCSC method. Can someone confirm this implementation is not present in Breeze? If so I add it

cheers

Contributor guide

Tech stack
scala
Domain
data
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Scala basicsfamiliarity with Breeze linear algebraunderstanding of CSC matrices
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Investigate the existing multiplication methods in CSCMatrixOps.scala, specifically the canMulSVt CSC eq SVt method used for Transpose(SparseVector) * CSCMatrix. Implement a similar method for Transpose(DenseVector) * CSCMatrix, ensuring the result type is Transpose(DenseVector). Add unit tests following the library's testing conventions.