TSparseMtx.Diag Method

TSparseMtx Class

void Diag(TVec Vec, Int32 kk)

Copies the kk-th diagonal of TSparseMtx to the Vec object.

#NameTypeDescription
1VecTVecsource TVec
2kkInt32

Result: stored in self (calling object)

Remarks:

Copies the kk-th diagonal of TSparseMtx to the Vec object. If k = 0 then the main diagonal matrix is obtained, if k < 0 then the k-th subdiagonal matrix is obtained and if k > 0 the then the k-th super diagonal is copied to Vec. The Vec parameters size is set automatically.

Examples
using Dew.Math;
using Dew.Math.Units;

namespace Dew.Examples
{
    private void Example()
    {
        Vector d = new Vector(0);
        TSparseMtx asp = new TSparseMtx();
        TSparseMtx bsp = new TSparseMtx();
        TSparseMtx csp = new TSparseMtx();
        TSparseMtx dsp = new TSparseMtx();
        // ...
        // #1 : split asp into lower(bsp), upper(csp) and diagonal(d) sections
        bsp.LowerTriangle(asp);
        csp.UpperTriangle(asp);
        asp.Diag(d);
        // now combine lower(bsp), upper, and diagonal(d) back
        dsp.AddSplit(bsp,d,csp);
    }
}