vlt.neuro.reverse_correlation.hartley.build

  BUILD - build a Hartley structure to rapidly draw Hartley stimuli

  HSTRUCT = vlt.neuro.reverse_correlation.hartley.build(M, KMAX, LMAX, NORM_MAX)

  Computes a structure that allows easy drawing (with rotation and repetition) of a Hartley
  stimulus from Ringach et al. 1997. It is compact in memory and can be used to give input
  to Psychtoolbox or other GPU renderers for fast drawing with minimal memory.

  The image rotation used here works best for M > 50 and for K,L < M/2. This will not
  faithfully reproduce the basis functions for M<50 or K,L near M, due to aliasing.

  Inputs:
     M is the number of pixels per edge of the image (the image is square).
     KMAX is the number of Hartley components to use in X. Components from -KMAX...KMAX will be used.
     LMAX is the number of Hartley components to use in Y. Components from -LMAX...LMAX will be used.
     NORMMAX - components will only be included if they also are less than NORMMAX, where sqrt(K^2+L^2)<=NORMMAX

  See also: vlt.neuro.reverse_correlation.hartley.draw, vlt.neuro.reverse_correlation.hartley.hartley_image