Ask HN: A good C++ multi-dimensional array library? | Hacker News Reader

Ask HN: A good C++ multi-dimensional array library?

6 pointshatred5 comments

I was working on a project which involved replacing our old numerical library back-end to some other newer alternative. I had a look at the possible options(Eigen/NT2/Armadillo/MTL4 among others) and decided to move on with Eigen. However, Eigen does not have a multi-dimensional array implementation. It can only support upto 2-D arrays. I was wondering if there are some C++ multi-dimensional libraries you folks might know of ?

Upto now, all I could find was:-

- Boost MultiArrays( specifying dimensions and size at compile time make it a no-go for me ) - Blitz++ ( same issues as above i.e. dimension needs to be specified at compile time )

It will be great if I could find something like a free version of RogueWave arrays which can be declared without specifying dimensions.

Thanks for reading through the post.

Sparse matrices or not? You could look into OpenCV's Mat and SparseMat here: http://docs.opencv.org/modules/core/doc/basic_structures.htm...

Thanks for the reply slavio.

- It seems that no expression template machinery is being used? Hence, it might be too slow for most basic operations for us due to creation of temporaries. - Does not have support for n-dimensional views. You can only get a view upon contiguous rows or columns. ( However, I might ignore this if the first point is settled ) - No vectorization support etc which you get with other libraries like Eigen/NT2 among others.

I might be wrong on some points though.

I dont know which operations you are going to do with the arrays but what about just use a array of arrays or matrices of matrices of matrices of...?

I am willing go give away everything for now and just have support for basic arithmetic operations, creation of sub matrix views ala numpy for the time being. I will be able to do the other operations via Eigen by creating a view over the native array. I hate the idea of creating an array of arrays though.

Hateing the idea of array of arraya is like hating recursivity.

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