-# Copyright\r
-\r
-"""Define functions for handling numbers in SI notation.\r
-\r
-Notes\r
------\r
-To output a scale, choose any value on the axis and find the\r
-multiplier and prefix for it. Use those to format the rest of the\r
-scale. As values can span several orders of magnitude, you have\r
-to decide what units to use.\r
-\r
->>> xs = (985e-12, 1e-9, 112358e-12)\r
-\r
-Get the power from the first (or last, or middle, ...) value\r
-\r
->>> p = get_power(xs[0])\r
->>> for x in xs:\r
-... print ppSI(x, decimals=2, power=p)\r
-985.00 p\r
-1000.00 p\r
-112358.00 p\r
->>> print prefix_from_value(xs[0]) + 'N'\r
-pN\r
-"""\r
-\r
-import math\r
-from numpy import isnan\r
-import re\r
-\r
-\r
-PREFIX = {\r
- 24: 'Y',\r
- 21: 'Z',\r
- 18: 'E',\r
- 15: 'P',\r
- 12: 'T',\r
- 9: 'G',\r
- 6: 'M',\r
- 3: 'k',\r
- 0: '',\r
- -3: 'm',\r
- -6: u'\u00B5',\r
- -9: 'n',\r
- -12: 'p',\r
- -15: 'f',\r
- -18: 'a',\r
- -21: 'z',\r
- -24: 'y',\r
- }\r
-"""A dictionary of SI prefixes from 10**24 to 10**-24.\r
-\r
-Examples\r
---------\r
->>> PREFIX[0]\r
-''\r
->>> PREFIX[6]\r
-'M'\r
->>> PREFIX[-9]\r
-'n'\r
-"""\r
-\r
-_DATA_LABEL_REGEXP = re.compile('^([^(]*[^ ]) ?\(([^)]*)\)$')\r
-"""Used by :func:`data_label_unit`.\r
-"""\r
-\r
-\r
-def ppSI(value, unit='', decimals=None, power=None, pad=False):\r
- """Pretty-print `value` in SI notation.\r
-\r
- The current implementation ignores `pad` if `decimals` is `None`.\r
-\r
- Examples\r
- --------\r
- >>> x = math.pi * 1e-8\r
- >>> print ppSI(x, 'N')\r
- 31.415927 nN\r
- >>> print ppSI(x, 'N', 3)\r
- 31.416 nN\r
- >>> print ppSI(x, 'N', 4, power=-12)\r
- 31415.9265 pN\r
- >>> print ppSI(x, 'N', 5, pad=True)\r
- 31.41593 nN\r
-\r
- If you want the decimal indented by six spaces with `decimal=2`,\r
- `pad` should be the sum of\r
-\r
- * 6 (places before the decimal point)\r
- * 1 (length of the decimal point)\r
- * 2 (places after the decimal point)\r
-\r
- >>> print ppSI(-x, 'N', 2, pad=(6+1+2))\r
- -31.42 nN\r
- """\r
- if value == 0:\r
- return '0'\r
- if isnan(value):\r
- return 'NaN'\r
-\r
- if power == None: # auto-detect power\r
- power = get_power(value)\r
-\r
- if decimals == None:\r
- format = lambda n: '%f' % n\r
- else:\r
- if pad == False: # no padding\r
- format = lambda n: '%.*f' % (decimals, n) \r
- else:\r
- if pad == True: # auto-generate pad\r
- # 1 for ' ', 1 for '-', 3 for number, 1 for '.', and decimals.\r
- pad = 6 + decimals\r
- format = lambda n: '%*.*f' % (pad, decimals, n)\r
- return '%s %s%s' % (format(value / pow(10,power)), PREFIX[power], unit)\r
-\r
-\r
-def get_power(value):\r
- """Return the SI power for which `0 <= |value|/10**pow < 1000`. \r
- \r
- Exampes\r
- -------\r
- >>> get_power(0)\r
- 0\r
- >>> get_power(123)\r
- 0\r
- >>> get_power(-123)\r
- 0\r
- >>> get_power(1e8)\r
- 6\r
- >>> get_power(1e-16)\r
- -18\r
- """\r
- if value != 0 and not isnan(value):\r
- # get log10(|value|)\r
- value_temp = math.floor(math.log10(math.fabs(value)))\r
- # reduce the log10 to a multiple of 3\r
- return int(value_temp - (value_temp % 3))\r
- else:\r
- return 0\r
-\r
-def prefix_from_value(value):\r
- """Determine the SI power of `value` and return its prefix.\r
-\r
- Examples\r
- --------\r
- >>> prefix_from_value(0)\r
- ''\r
- >>> prefix_from_value(1e10)\r
- 'G'\r
- """\r
- return PREFIX[get_power(value)]\r
-\r
-def split_data_label(label):\r
- """Split `curve.data[i].info['name']` labels into `(name, unit)`.\r
-\r
- Examples\r
- --------\r
- >>> split_data_label('z piezo (m)')\r
- ('z piezo', 'm')\r
- >>> split_data_label('deflection (N)')\r
- ('deflection', 'N')\r
- """\r
- m = _DATA_LABEL_REGEXP.match(label)\r
- assert m != None, label\r
- return m.groups()\r
+# Copyright (C) 2010 Massimo Sandal <devicerandom@gmail.com>
+# Rolf Schmidt <rschmidt@alcor.concordia.ca>
+# W. Trevor King <wking@drexel.edu>
+#
+# This file is part of Hooke.
+#
+# Hooke is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# Hooke 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 Lesser General
+# Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with Hooke. If not, see
+# <http://www.gnu.org/licenses/>.
+
+"""Define functions for handling numbers in SI notation.
+
+Notes
+-----
+To output a scale, choose any value on the axis and find the
+multiplier and prefix for it. Use those to format the rest of the
+scale. As values can span several orders of magnitude, you have
+to decide what units to use.
+
+>>> xs = (985e-12, 1e-9, 112358e-12)
+
+Get the power from the first (or last, or middle, ...) value
+
+>>> p = get_power(xs[0])
+>>> for x in xs:
+... print ppSI(x, decimals=2, power=p)
+985.00 p
+1000.00 p
+112358.00 p
+>>> print prefix_from_value(xs[0]) + 'N'
+pN
+"""
+
+import math
+from numpy import isnan
+import re
+
+
+PREFIX = {
+ 24: 'Y',
+ 21: 'Z',
+ 18: 'E',
+ 15: 'P',
+ 12: 'T',
+ 9: 'G',
+ 6: 'M',
+ 3: 'k',
+ 0: '',
+ -3: 'm',
+ -6: u'\u00B5',
+ -9: 'n',
+ -12: 'p',
+ -15: 'f',
+ -18: 'a',
+ -21: 'z',
+ -24: 'y',
+ }
+"""A dictionary of SI prefixes from 10**24 to 10**-24.
+
+Examples
+--------
+>>> PREFIX[0]
+''
+>>> PREFIX[6]
+'M'
+>>> PREFIX[-9]
+'n'
+"""
+
+_DATA_LABEL_REGEXP = re.compile('^([^(]*[^ ]) ?\(([^)]*)\)$')
+"""Used by :func:`data_label_unit`.
+"""
+
+
+def ppSI(value, unit='', decimals=None, power=None, pad=False):
+ """Pretty-print `value` in SI notation.
+
+ The current implementation ignores `pad` if `decimals` is `None`.
+
+ Examples
+ --------
+ >>> x = math.pi * 1e-8
+ >>> print ppSI(x, 'N')
+ 31.415927 nN
+ >>> print ppSI(x, 'N', 3)
+ 31.416 nN
+ >>> print ppSI(x, 'N', 4, power=-12)
+ 31415.9265 pN
+ >>> print ppSI(x, 'N', 5, pad=True)
+ 31.41593 nN
+
+ If you want the decimal indented by six spaces with `decimal=2`,
+ `pad` should be the sum of
+
+ * 6 (places before the decimal point)
+ * 1 (length of the decimal point)
+ * 2 (places after the decimal point)
+
+ >>> print ppSI(-x, 'N', 2, pad=(6+1+2))
+ -31.42 nN
+ """
+ if value == 0:
+ return '0'
+ if isnan(value):
+ return 'NaN'
+
+ if power == None: # auto-detect power
+ power = get_power(value)
+
+ if decimals == None:
+ format = lambda n: '%f' % n
+ else:
+ if pad == False: # no padding
+ format = lambda n: '%.*f' % (decimals, n)
+ else:
+ if pad == True: # auto-generate pad
+ # 1 for ' ', 1 for '-', 3 for number, 1 for '.', and decimals.
+ pad = 6 + decimals
+ format = lambda n: '%*.*f' % (pad, decimals, n)
+ return '%s %s%s' % (format(value / pow(10,power)), PREFIX[power], unit)
+
+
+def get_power(value):
+ """Return the SI power for which `0 <= |value|/10**pow < 1000`.
+
+ Exampes
+ -------
+ >>> get_power(0)
+ 0
+ >>> get_power(123)
+ 0
+ >>> get_power(-123)
+ 0
+ >>> get_power(1e8)
+ 6
+ >>> get_power(1e-16)
+ -18
+ """
+ if value != 0 and not isnan(value):
+ # get log10(|value|)
+ value_temp = math.floor(math.log10(math.fabs(value)))
+ # reduce the log10 to a multiple of 3
+ return int(value_temp - (value_temp % 3))
+ else:
+ return 0
+
+def prefix_from_value(value):
+ """Determine the SI power of `value` and return its prefix.
+
+ Examples
+ --------
+ >>> prefix_from_value(0)
+ ''
+ >>> prefix_from_value(1e10)
+ 'G'
+ """
+ return PREFIX[get_power(value)]
+
+def split_data_label(label):
+ """Split `curve.data[i].info['name']` labels into `(name, unit)`.
+
+ Examples
+ --------
+ >>> split_data_label('z piezo (m)')
+ ('z piezo', 'm')
+ >>> split_data_label('deflection (N)')
+ ('deflection', 'N')
+ """
+ m = _DATA_LABEL_REGEXP.match(label)
+ assert m != None, label
+ return m.groups()
projects / hooke.git / blobdiff