TSparseMtx.Diag Method

Summary

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

Declaration

Procedure Diag(Vec: TVec; kk: integer = 0);

Description

Sets the kk-th diagonal of TSparseMtx to the Vec object. If k = 0 then the main diagonal matrix is set, if k < 0 then the k-th subdiagonal matrix is set and if k > 0 the then the k-th super diagonal is set. The matrix must be large enough to hold diagonal or an exception is raised.

Example 1

          uses MtxExpr, Sparse;

          procedure Example;
          var asp, bsp: TSparseMtx;
            csp, dsp: TSparseMtx;
            d: Vector;
          begin
            // ...
            // #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);
            // should be equal
            if not asp.Equal(dsp) then Eraise('Not Equal!');
          end;

          #include "MtxVecCpp.h"
          #include "Sparse.hpp"
          void __fastcall Example()
          {
            Vector d;
            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);
            // should be equal
            if (!asp->Equal(dsp)) ERaise("Not Equal!");

            delete asp;
            delete bsp;
            delete csp;
            delete dsp;
          }