Source code for PyMca5.PyMcaMath.SpecArithmetic

#/*##########################################################################
#
# The PyMca X-Ray Fluorescence Toolkit
#
# Copyright (c) 2004-2014 European Synchrotron Radiation Facility
#
# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
# the ESRF by the Software group.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
#############################################################################*/
__author__ = "V.A. Sole - ESRF Data Analysis"
__contact__ = "sole@esrf.fr"
__license__ = "MIT"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"
__doc__ = """
This module implements several mathematical functions:
    - peak search
    - center of mass search
    - fwhm search
WARNING : array are numpy.ndarray objects.
"""

import numpy

[docs]def search_peak(xdata, ydata): """ Search a peak and its position in arrays xdata ad ydata. Return three integer: - peak position - peak value - index of peak position in array xdata This result may accelerate the fwhm search. """ ymax = max(ydata) idx = __give_index(ymax,ydata) return xdata[idx],ymax,idx
[docs]def search_com(xdata,ydata): """ Return the center of mass in arrays xdata and ydata """ num = numpy.sum(xdata*ydata) denom = numpy.sum(ydata).astype(numpy.float) try: result = num/denom except ZeroDivisionError: result = 0 return result
[docs]def search_fwhm(xdata,ydata,peak=None,index=None): """ Search a fwhm and its center in arrays xdata and ydatas. If no fwhm is found, (0,0) is returned. peak and index which are coming from search_peak result, may accelerate calculation """ if peak is None or index is None: x,mypeak,index_peak = search_peak(xdata,ydata) else: mypeak = peak index_peak = index hm = mypeak/2 idx = index_peak try: while ydata[idx] >= hm: idx = idx-1 x0 = xdata[idx] x1 = xdata[idx+1] y0 = ydata[idx] y1 = ydata[idx+1] lhmx = (hm*(x1-x0) - (y0*x1)+(y1*x0)) / (y1-y0) except ZeroDivisionError: lhmx = 0 except IndexError: lhmx = xdata[0] idx = index_peak try: while ydata[idx] >= hm: idx = idx+1 x0 = xdata[idx] x1 = xdata[idx+1] y0 = ydata[idx] y1 = ydata[idx+1] uhmx = (hm*(x1-x0) - (y0*x1)+(y1*x0)) / (y1-y0) except ZeroDivisionError: uhmx = 0 except IndexError: uhmx = xdata[-1] FWHM = uhmx - lhmx CFWHM = (uhmx+lhmx)/2 return FWHM,CFWHM
def __give_index(elem,array): """ Return the index of elem in array """ mylist = array.tolist() return mylist.index(elem)
[docs]def test(): pass
if __name__ == '__main__': test()