F＃中的数组串联

Question

Are there any analogs to Matlab's horzcat () and vertcat () functions in F#? Because what I'm doing now seems asinine. There is a related question here but it seems pretty dated.

    let arr = Array.init 5 (fun i -> 1.)
    let xMat = DenseMatrix.init l 2 (fun r c -> if c = 0 then 1. else arr.[r])

There is an Array.concat but it seems to work only vertically.

Answer 1

As far as I know, there is no built-in function to do this for F# arrays , but in your code you are ultimately working with matrices from Math.NET Numerics and Math.NET has functions to append matrices vertically and horizontally:

let m1 = DenseMatrix.init 5 1 (fun _ _ -> 1.)
let m2 = DenseMatrix.init 5 1 (fun _ _ -> 2.)

DenseMatrix.append [m1; m2] // Append matrices horizontally
DenseMatrix.stack [m1; m2]  // Append matrices vertically