TVec.Hilbert Method

Summary

The fast hilbert transform (FFT based).

Class
TVec

Declaration

Function Hilbert(Vec: TVec): TVec;

Description

The method forms the imaginary orthogonal part (90 degrees phase shifted version of the original) from the real series by using the fast hilbert transform (FFT based) and saves the complex result in the calling vector. No windowing is performed. Vec must be a real vector or an exception is raised. The Length and Complex properties of the calling vector are set implicitly to match Vec vector.

See Also
FFT
DCT

Example 1

        var a,b,Re,Im: TVec;
            azero: TSample;
        begin
          CreateIt(a,b,Re,Im);
          try
            a.SetIt(false,[1,2,3,4,5,6,7,8]);
            b.Hilbert(a);
            Re.RealPart(b);
            Im.ImagPart(b);
            azero := Re.DotProd(Im);
            // if Re is orthogonal to Im, azero becomes 0
          finally
            FreeIt(a,b,Re,Im);
          end;
        end;