TCONV Twisted convolution
Usage: h=tconv(f,g);
TCONV(f,g) computes the twisted convolution of the square matrices
f and g.
Let h=TCONV(f,g) for f,g being L xL matrices. Then h is given by
L-1 L-1
h(m+1,n+1) = sum sum f(k+1,l+1)*g(m-k+1,n-l+1)*exp(-2*pi*i*(m-k)*l/L);
l=0 k=0
where m-k and n-l are computed modulo L.
If both f and g are of class sparse then h will also be a sparse
matrix. The number of non-zero elements of h is usually much larger than
the numbers for f and g. Unless f and g are very sparse, it can be
faster to convert them to full matrices before calling TCONV.
The routine SPREADINV can be used to calculate an inverse convolution.
Define h and r by:
h=tconv(f,g);
r=tconv(spreadinv(f),h);
then r is equal to g.
Url: http://ltfat.github.io/doc/gabor/tconv.html
See also: spreadop, spreadfun, spreadinv.
Package: ltfat