# magni.cs.reconstruction.it._threshold module¶

Module providing functions for calculating a threshold (level) used in Iterative Threshold algorithms.

## Routine listings¶

calculate_far(delta)
Calculate the optimal False Acceptance Rate for a given indeterminacy.
calculate_using_far(var)
Calculate a threshold level using the FAR heuristic.
calculate_using_fixed(var)
Calculate a threshold level using a given fixed support size.
get_function_handle(method)
Return a function handle to a given calculation method.
magni.cs.reconstruction.it._threshold.calculate_far(delta, it_algorithm)[source]

Calculate the optimal False Acceptance Rate for a given indeterminacy.

Parameters: delta (float) – The indeterminacy, m / n, of a system of equations of size m x n. it_algorithm ({IHT, ITS}) – The iterative thresholding algorithm to calculate the FAR for. FAR (float) – The optimal False Acceptance Rate for the given indeterminacy.

Notes

The optimal False Acceptance Rate to be used in connection with the interference heuristic presented in the paper “Optimally Tuned Iterative Reconstruction Algorithms for Compressed Sensing” [1] is calculated from a set of optimal values presented in the same paper. The calculated value is found from a linear interpolation or extrapolation on the known set of optimal values.

References

 [1] A. Maleki and D.L. Donoho, “Optimally Tuned Iterative Reconstruction Algorithms for Compressed Sensing”, IEEE Journal Selected Topics in Signal Processing, vol. 3, no. 2, pp. 330-341, Apr. 2010.
magni.cs.reconstruction.it._threshold.wrap_calculate_using_far(var)[source]

Arguments wrapper for calculate_using_far.

Calculate a threshold level using the FAR heuristic.

magni.cs.reconstruction.it._threshold.wrap_calculate_using_fixed(var)[source]

Arguments wrapper for calculate_using_fixed.

Calculate a threshold level using a given fixed support size.

magni.cs.reconstruction.it._threshold.get_function_handle(method, var)[source]

Return a function handle to a given calculation method.

Parameters: method (str) – Identifier of the calculation method to return a handle to. var (dict) – Local variables needed in the threshold method. f_handle (function) – Handle to calculation method defined in this globals scope.