source: trunk/GSASIIpy3.py @ 1236

Last change on this file since 1236 was 1236, checked in by toby, 8 years ago

Add FXYE & XYE exporters; allow multiple powder exports; fix formatting of float32 intensities (which should be gone); minor sequential refinement changes; remove old export patterns items; new padded format routine

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File size: 6.2 KB
Line 
1'''
2*GSASIIpy3: Python 3.x Routines*
3================================
4
5Module to hold python 3-compatible code, to keep it separate from
6code that will break with __future__ options.
7
8'''
9from __future__ import division
10import numpy as np
11import GSASIIpath
12GSASIIpath.SetVersionNumber("$Revision: 1236 $")
13# de
14sind = sin = s = lambda x: np.sin(x*np.pi/180.)
15cosd = cos = c = lambda x: np.cos(x*np.pi/180.)
16tand = tan = t = lambda x: np.tan(x*np.pi/180.)
17sqrt = sq = lambda x: np.sqrt(x)
18pi = np.pi
19
20def FormulaEval(string):
21    '''Evaluates a algebraic formula into a float, if possible. Works
22    properly on fractions e.g. 2/3 only with python 3.0+ division.
23
24    Expressions such as 2/3, 3*pi, sin(45)/2, 2*sqrt(2), 2**10 can all
25    be evaluated.
26
27    :param str string: Character string containing a Python expression
28      to be evaluated.
29
30    :returns: the value for the expression as a float or None if the expression does not
31      evaluate to a valid number.
32   
33    '''
34    try:
35        val = float(eval(string))
36        if np.isnan(val) or np.isinf(val): return None
37    except:
38        return None
39    return val
40
41def FormatPadValue(val,maxdigits=None):
42    '''Format a float to fit in ``maxdigits[0]`` spaces with maxdigits[1] after decimal.
43
44    :param float val: number to be formatted.
45
46    :param list maxdigits: the number of digits & places after decimal to be used for display of the
47      number (defaults to [10,2]).
48
49    :returns: a string with exactly maxdigits[0] characters (except under error conditions),
50      but last character will always be a space
51    '''
52    if maxdigits is None:
53        digits = [10,2]
54    else:
55        digits = maxdigits
56    fmt = '{:'+str(digits[0])+'}'
57    s = fmt.format(FormatValue(val,digits))
58    if s[-1] == ' ':
59        return s
60    else:
61        return s+' '
62   
63
64def FormatValue(val,maxdigits=None):
65    '''Format a float to fit in ``maxdigits[0]`` spaces with maxdigits[1] after decimal.
66
67    :param float val: number to be formatted.
68
69    :param list maxdigits: the number of digits & places after decimal to be used for display of the
70      number (defaults to [10,2]).
71
72    :returns: a string with <= maxdigits characters (usually). 
73    '''
74    if maxdigits is None:
75        digits = [10,2]
76    else:
77        digits = maxdigits
78    # does the standard str() conversion fit?
79    string = str(val)
80    if len(string) <= digits[0]: return string.strip()
81    # negative numbers, leave room for a sign
82    if val < 0: digits[0] -= 1
83    decimals = digits[0] - digits[1]
84    if abs(val) < 1e-99 or abs(val) > 1e99:
85        decimals = min(digits[0]-6,digits[1])
86        fmt = "{" + (":{:d}.{:d}g".format(digits[0],decimals))+"}" # create format string
87    elif abs(val) < 1e-9 or abs(val) > 1e9:
88        decimals = min(digits[0]-5,digits[1])
89        fmt = "{" + (":{:d}.{:d}g".format(digits[0],decimals))+"}"
90    elif abs(val) < 10**(4-decimals): # make sure at least 4 decimals show
91        decimals = min(digits[0]-5,digits[1])
92        fmt = "{" + (":{:d}.{:d}g".format(digits[0],decimals))+"}"
93    elif abs(val) >= 10**decimals: # deal with large numbers in smaller spaces
94        decimals = min(digits[0]-5,digits[1])
95        fmt = "{" + (":{:d}.{:d}g".format(digits[0],decimals))+"}"
96    elif abs(val) < 1: # use f format for small numbers
97        decimals = min(digits[0]-3,digits[1])
98        fmt = "{" + (":{:d}.{:d}f".format(digits[0],decimals))+"}"
99    else: # in range where g formatting should do what I want
100        decimals = digits[0] - 1
101        fmt = "{" + (":{:d}.{:d}g".format(digits[0],decimals))+"}"
102    try:
103        return fmt.format(float(val)).strip()
104    except ValueError as err:
105        print 'FormatValue Error with val,maxdigits,fmt=',val,maxdigits,fmt
106        return str(val)
107
108def FormatSigFigs(val, maxdigits=10, sigfigs=5, treatAsZero=1e-20):
109    '''Format a float to use ``maxdigits`` or fewer digits with ``sigfigs``
110    significant digits showing (if room allows).
111
112    :param float val: number to be formatted.
113
114    :param int maxdigits: the number of digits to be used for display of the
115       number (defaults to 10).
116
117    :param int sigfigs: the number of significant figures to use, if room allows
118
119    :param float treatAsZero: numbers that are less than this in magnitude
120      are treated as zero. Defaults to 1.0e-20, but this can be disabled
121      if set to None.
122
123    :returns: a string with <= maxdigits characters (I hope). 
124    '''
125    if treatAsZero is not None:
126        if abs(val) < treatAsZero:
127            return '0.0'
128    # negative numbers, leave room for a sign
129    if val < 0: maxdigits -= 1
130    if abs(val) < 1e-99 or abs(val) > 9.999e99:
131        decimals = min(maxdigits-6,sigfigs)
132        fmt = "{" + (":{:d}.{:d}g".format(maxdigits,decimals))+"}" # create format string
133    elif abs(val) < 1e-9 or abs(val) > 9.999e9:
134        decimals = min(maxdigits-5,sigfigs)
135        fmt = "{" + (":{:d}.{:d}g".format(maxdigits,decimals))+"}"
136    elif abs(val) < 9.9999999*10**(sigfigs-maxdigits):
137        decimals = min(maxdigits-5,sigfigs)
138        fmt = "{" + (":{:d}.{:d}g".format(maxdigits,decimals))+"}"
139    elif abs(val) >= 10**sigfigs: # deal with large numbers in smaller spaces
140        decimals = min(maxdigits-5,sigfigs)
141        fmt = "{" + (":{:d}.{:d}g".format(maxdigits,decimals))+"}"
142    elif abs(val) < 1: # small numbers, add to decimal places
143        decimals = sigfigs - int(np.log10(abs(val)))
144        fmt = "{" + (":{:d}.{:d}f".format(maxdigits,decimals))+"}"
145    else: # larger numbers, remove decimal places
146        decimals = sigfigs - 1 - int(np.log10(abs(val)))
147        fmt = "{" + (":{:d}.{:d}f".format(maxdigits,decimals))+"}"
148        if decimals == 0: fmt += "." # force a decimal place
149    try:
150        return fmt.format(float(val)).strip()
151    except ValueError as err:
152        print 'FormatValue Error with val,maxdigits, sigfigs, fmt=',val, maxdigits,sigfigs, fmt
153        return str(val)
154
155if __name__ == '__main__':
156    for i in (1.23456789e-129,1.23456789e129,1.23456789e-99,1.23456789e99,-1.23456789e-99,-1.23456789e99):
157        print FormatSigFigs(i),i
158    for i in (1,10,100,1000,10000,100000,1000000,10000000,100000000,1000000000):
159        print FormatSigFigs(1.23456789e-9*i),1.23456789e-9*i
160    for i in (1,10,100,1000,10000,100000,1000000,10000000,100000000):
161        print FormatSigFigs(1.23456789e9/i),1.23456789e9/i
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