Multi-Dimensional Matrix

MDMatrix.swift

import Cocoa

//No bounds checking
struct Matrix {
    let dims:[Int]
    let increaseDim:[Int]
    var grid: [Double]
    init(dim: Int...) {
        self.dims = dim
        var tmpInDim:[Int] = [1]
        var totalElement = 1
        for tmpvar in dim {
            totalElement *= tmpvar
        }
        
        for i in 1..<dim.count {
            tmpInDim.append(tmpInDim[i-1]*dim[i-1]);
        }
        self.increaseDim = tmpInDim
        grid = Array(count: totalElement, repeatedValue: 0.0)
    }
    subscript(index:Int...) -> Double {
        get {
            var ind = 0
            for i in 0..<index.count {
                ind += index[i]*self.increaseDim[i]
            }
            return grid[ind]
        }
        set(newValue) {
            var ind = 0
            for i in 0..<index.count {
                ind += index[i]*self.increaseDim[i]
            }
            grid[ind] = newValue
        }
    }
}

//Example (3D matrix)
var e = Matrix(dim: 2,3,4)
//Use subscript,
e[0,2,2] = 4
//Or index
e[23] = 6