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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
#!/usr/bin/env python3
"""
pint-convert
~~~~~~~~~~~~
:copyright: 2020 by Pint Authors, see AUTHORS for more details.
:license: BSD, see LICENSE for more details.
"""
from __future__ import annotations
import argparse
import re
from pint import UnitRegistry
parser = argparse.ArgumentParser(description="Unit converter.", usage=argparse.SUPPRESS)
parser.add_argument(
"-s",
"--system",
metavar="sys",
default="SI",
help="unit system to convert to (default: SI)",
)
parser.add_argument(
"-p",
"--prec",
metavar="n",
type=int,
default=12,
help="number of maximum significant figures (default: 12)",
)
parser.add_argument(
"-u",
"--prec-unc",
metavar="n",
type=int,
default=2,
help="number of maximum uncertainty digits (default: 2)",
)
parser.add_argument(
"-U",
"--no-unc",
dest="unc",
action="store_false",
help="ignore uncertainties in constants",
)
parser.add_argument(
"-C",
"--no-corr",
dest="corr",
action="store_false",
help="ignore correlations between constants",
)
parser.add_argument(
"fr", metavar="from", type=str, help="unit or quantity to convert from"
)
parser.add_argument("to", type=str, nargs="?", help="unit to convert to")
try:
args = parser.parse_args()
except SystemExit:
parser.print_help()
raise
ureg = UnitRegistry()
ureg.auto_reduce_dimensions = True
ureg.autoconvert_offset_to_baseunit = True
ureg.enable_contexts("Gau", "ESU", "sp", "energy", "boltzmann")
ureg.default_system = args.system
if args.unc:
import uncertainties
# Measured constants subject to correlation
# R_i: Rydberg constant
# g_e: Electron g factor
# m_u: Atomic mass constant
# m_e: Electron mass
# m_p: Proton mass
# m_n: Neutron mass
R_i = (ureg._units["R_inf"].converter.scale, 0.0000000000021e7)
g_e = (ureg._units["g_e"].converter.scale, 0.00000000000035)
m_u = (ureg._units["m_u"].converter.scale, 0.00000000050e-27)
m_e = (ureg._units["m_e"].converter.scale, 0.00000000028e-30)
m_p = (ureg._units["m_p"].converter.scale, 0.00000000051e-27)
m_n = (ureg._units["m_n"].converter.scale, 0.00000000095e-27)
if args.corr:
# Correlation matrix between measured constants (to be completed below)
# R_i g_e m_u m_e m_p m_n
corr = [
[1.0, -0.00206, 0.00369, 0.00436, 0.00194, 0.00233], # R_i
[-0.00206, 1.0, 0.99029, 0.99490, 0.97560, 0.52445], # g_e
[0.00369, 0.99029, 1.0, 0.99536, 0.98516, 0.52959], # m_u
[0.00436, 0.99490, 0.99536, 1.0, 0.98058, 0.52714], # m_e
[0.00194, 0.97560, 0.98516, 0.98058, 1.0, 0.51521], # m_p
[0.00233, 0.52445, 0.52959, 0.52714, 0.51521, 1.0],
] # m_n
(R_i, g_e, m_u, m_e, m_p, m_n) = uncertainties.correlated_values_norm(
[R_i, g_e, m_u, m_e, m_p, m_n], corr
)
else:
R_i = uncertainties.ufloat(*R_i)
g_e = uncertainties.ufloat(*g_e)
m_u = uncertainties.ufloat(*m_u)
m_e = uncertainties.ufloat(*m_e)
m_p = uncertainties.ufloat(*m_p)
m_n = uncertainties.ufloat(*m_n)
ureg._units["R_inf"].converter.scale = R_i
ureg._units["g_e"].converter.scale = g_e
ureg._units["m_u"].converter.scale = m_u
ureg._units["m_e"].converter.scale = m_e
ureg._units["m_p"].converter.scale = m_p
ureg._units["m_n"].converter.scale = m_n
# Measured constants with zero correlation
ureg._units["gravitational_constant"].converter.scale = uncertainties.ufloat(
ureg._units["gravitational_constant"].converter.scale, 0.00015e-11
)
ureg._units["d_220"].converter.scale = uncertainties.ufloat(
ureg._units["d_220"].converter.scale, 0.000000032e-10
)
ureg._units["K_alpha_Cu_d_220"].converter.scale = uncertainties.ufloat(
ureg._units["K_alpha_Cu_d_220"].converter.scale, 0.00000022
)
ureg._units["K_alpha_Mo_d_220"].converter.scale = uncertainties.ufloat(
ureg._units["K_alpha_Mo_d_220"].converter.scale, 0.00000019
)
ureg._units["K_alpha_W_d_220"].converter.scale = uncertainties.ufloat(
ureg._units["K_alpha_W_d_220"].converter.scale, 0.000000098
)
ureg._root_units_cache = dict()
ureg._build_cache()
def convert(u_from, u_to=None, unc=None, factor=None):
q = ureg.Quantity(u_from)
fmt = ".{}g".format(args.prec)
if unc:
q = q.plus_minus(unc)
if u_to:
nq = q.to(u_to)
else:
nq = q.to_base_units()
if factor:
q *= ureg.Quantity(factor)
nq *= ureg.Quantity(factor).to_base_units()
prec_unc = use_unc(nq.magnitude, fmt, args.prec_unc)
if prec_unc > 0:
fmt = ".{}uS".format(prec_unc)
else:
try:
nq = nq.magnitude.n * nq.units
except Exception:
pass
fmt = "{:" + fmt + "} {:~P}"
print(("{:} = " + fmt).format(q, nq.magnitude, nq.units))
def use_unc(num, fmt, prec_unc):
unc = 0
try:
if isinstance(num, uncertainties.UFloat):
full = ("{:" + fmt + "}").format(num)
unc = re.search(r"\+/-[0.]*([\d.]*)", full).group(1)
unc = len(unc.replace(".", ""))
except Exception:
pass
return max(0, min(prec_unc, unc))
convert(args.fr, args.to)
|
