Source code for sane

#!/usr/bin/env python 
# encoding: utf-8

"""plugin for Sane denoising

This plugin implements the SANE denoising algorithm, 
SANE is inspired from urQRd algorithm, but is improved in several points

- faster on vector length != 2**n
- much more efficient on weak signals
- requires less iterations and less overestimate of rank
- however, a non productive iteration is always performed,
  so processing time for I iterations of SANE should be compared
  with I+1 iterations of urQRd.

associated publications
- Bray, F., Bouclon, J., Chiron, L., Witt, M., Delsuc, M.-A., & Rolando, C. (2017).
  Nonuniform Sampling Acquisition of Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Increased Mass Resolution of Tandem Mass Spectrometry Precursor Ions.
  Analytical Chemistry, acs.analchem.7b01850. http://doi.org/10.1021/acs.analchem.7b01850

- Chiron, L., van Agthoven, M. A., Kieffer, B., Rolando, C., & Delsuc, M.-A. (2014).
  Efficient denoising algorithms for large experimental datasets and their applications in Fourier transform ion cyclotron resonance mass spectrometry.
  PNAS , 111(4), 1385–1390. http://doi.org/10.1073/pnas.1306700111
"""

from __future__ import print_function
import sys #
import unittest

from spike.NPKData import NPKData_plugin, as_cpx, as_float, _base_fft,\
            _base_ifft, _base_rfft, _base_irfft
from spike.Algo.sane import sane
if sys.version_info[0] < 3:
    pass
else:
    xrange = range


def sane_plugin(npkd, rank, orda=None, iterations=1, axis=0, trick=True, optk=False, ktrick=False):
    """
    Apply "sane" denoising to data
    rank is about 2 x number_of_expected_lines
    Manages real and complex cases.
    Handles the case of hypercomplex for denoising of 2D FTICR for example.
    
    sane algorithm. Name stands for Support Selection for Noise Elimination.
    From a data series return a denoised series denoised
    data : the series to be denoised - a (normally complex) numpy buffer
    rank : the rank of the analysis
    orda : is the order of the analysis
        internally, a Hankel matrix (M,N) is constructed, with M = orda and N = len(data)-orda+1
        if None (default) orda = (len(data)+1)/2
    iterations : the number of time the operation should be repeated
    optk : if set to True will calculate the rank giving the best recovery for an automatic estimated noise level. 
    trick : permits to enhanced the denoising by using a cleaned signal as the projective space. "Support Selection"
    ktrick : if a value is given, it permits to change the rank on the second pass.
             The idea is that for the first pass a rank large enough as to be used to compensate for the noise while
             for the second pass a lower rank can be used. 
    
    """
    if npkd.dim == 1:
        if npkd.axis1.itype == 0:   # real
            buff = as_cpx(_base_ifft(_base_rfft(npkd.buffer)))       # real case, go to analytical signal
        else:   #complex
            buff = npkd.get_buffer()                       # complex case, makes complex
        sane_result = sane(buff, rank, orda=orda, trick=trick, iterations=iterations) # performs denoising
        if npkd.axis1.itype == 0:   # real
            buff = _base_irfft(_base_fft(as_float(sane_result)))      # real case, comes back to real
            npkd.set_buffer(buff)
        else:
            npkd.buffer = as_float(sane_result)             # complex case, makes real
    elif npkd.dim == 2:
        todo = npkd.test_axis(axis)
        if todo == 2:
            for i in xrange(npkd.size1):
                r = npkd.row(i).sane(rank=rank, orda=orda, iterations=iterations)
                npkd.set_row(i,r)
        elif todo == 1:
            for i in xrange(npkd.size2):
                r = npkd.col(i).sane(rank=rank, orda=orda, iterations=iterations)
                npkd.set_col(i,r)
    elif npkd.dim == 3:
        raise Exception("not implemented yet")
    return npkd


NPKData_plugin("sane", sane_plugin)