Function: projkern
PROJKERN  Projection onto generating kernel space
  Usage:  cout=projkern(cin,a);
          cout=projkern(cin,g,a);
          cout=projkern(cin,ga,gs,a);

  Input parameters:
        cin   : Input coefficients
        g     : analysis/synthesis window
        ga    : analysis window
        gs    : synthesis window
        a     : Length of time shift.
  Output parameters:
        cout  : Output coefficients

  cout=PROJKERN(cin,a) projects a set of Gabor coefficients c onto the
  space of possible Gabor coefficients. This means that cin and cout*
  synthesize to the same signal. A tight window generated from a Gaussian
  will be used for both analysis and synthesis.

  The rationale for this function is a follows: Because the coefficient
  space of a Gabor frame is larger than the signal space (since the frame
  is redundant) then there are many coefficients that correspond to the
  same signal.

  Therefore, you might desire to work with the coefficients cin, but you
  are in reality working with cout.

  cout=PROJKERN(cin,g,a) does the same, using the window g for analysis
  and synthesis.

  cout=PROJKERN(cin,ga,gs,a) does the same, but for different analysis
  ga and synthesis gs windows.

Url: http://ltfat.github.io/doc/gabor/projkern.html

See also: dgt, idgt.

Package: ltfat