An example showing how convolution is just a dot product

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This example shows how each point of a numerical convolution is just an inner (or dot) product. It is suitable as a starting point for an adaptive filter script.

function y = my_convolution(h,x)
% This function does convolution of a sequence x, with a set of FIR filter coefficients, h.
% It ignores the first points (length of the shorter vector) in the output.
% So the output is abs(lenght(x)-length(h))
% h and x are assumed to be row vectors.
Order = length(h);
NoOfData = length(x);
if (Order > NoOfData)
  temp=x; %Swap the x and h, because x*h = h*x and we need Order < NoOfData
  x=h;
  h=temp;
end
for n = Order : NoOfData
        D = x(n:-1:n-Order+1); 
        y(n) = h*D' ; % Convolution
end
end