1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
#/*##########################################################################
# Copyright (C) 2004-2012 European Synchrotron Radiation Facility
#
# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
# the ESRF by the Software group.
#
# This toolkit is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 2 of the License, or (at your option)
# any later version.
#
# PyMca is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# PyMca; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# PyMca follows the dual licensing model of Riverbank's PyQt and cannot be
# used as a free plugin for a non-free program.
#
# Please contact the ESRF industrial unit (industry@esrf.fr) if this license
# is a problem for you.
#############################################################################*/
#!/usr/bin/env python
"""
This module implements several mathematical functions:
- peak search
- center of mass search
- fwhm search
WARNING : array are numpy.ndarray objects.
"""
import numpy
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
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
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)
def test():
pass
if __name__ == '__main__':
test()
|
