Multiresolution hierarchical simulated annealing

This algorithm extends hsa() by introducing different grid levels, or resolutions, which should result in improved and more efficient reconstruction of larger particles.

mhsa(
  ti,
  dimensions = NULL,
  start_after = NULL,
  stop_after = NULL,
  stop_rejected = NULL,
  stop_at = 1e-06,
  order = NULL,
  distance = NULL,
  cool = 0.9,
  levels = 2
)

Arguments

ti

The original training image (2D array).

dimensions

Dimensions for the reconstruction (vector of length 2 or 3). Defaults to the dimensions of ti.

start_after

Number of iterations for determining the initial simulated annealing temperature. Defaults to 0.1% of the total amount of pixels in the reconstruction.

stop_after

Maximum number of iterations. Defaults to the amount of pixels in the reconstruction. Can be a vector for different values per phase.

stop_rejected

Maximum number of consecutively rejected iterations. Defaults to 1% of the total amount of pixels in the reconstruction.

stop_at

Target precision. Defaults to 1e-6.

order

Integer vector with the phase order for hierarchical simulation. Defaults to the least to the most occurring phase.

distance

Distance, in pixels, up to which to investigate the structural descriptors. Defaults to 1/4th of the minimum of dim(ti) and dimensions.

cool

Simulated annealing cooling factor. Must be lower than one. Defaults to 0.9.

levels

Amount of grid levels (or resolutions) to use for the reconstruction. Defaults to 2. Can be a vector to use different levels for different phases.

Value

A reconstructed 2D or 3D array.

References

https://doi.org/10.1103/PhysRevE.100.053316

See also

hsa(), nmhsa()