Pracownia_programowania/venv/Lib/site-packages/matplotlib/testing/jpl_units/UnitDbl.py

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2020-02-01 19:54:00 +01:00
"""UnitDbl module."""
import operator
class UnitDbl(object):
"""Class UnitDbl in development.
"""
# Unit conversion table. Small subset of the full one but enough
# to test the required functions. First field is a scale factor to
# convert the input units to the units of the second field. Only
# units in this table are allowed.
allowed = {
"m": (0.001, "km"),
"km": (1, "km"),
"mile": (1.609344, "km"),
"rad": (1, "rad"),
"deg": (1.745329251994330e-02, "rad"),
"sec": (1, "sec"),
"min": (60.0, "sec"),
"hour": (3600, "sec"),
}
_types = {
"km": "distance",
"rad": "angle",
"sec": "time",
}
def __init__(self, value, units):
"""Create a new UnitDbl object.
Units are internally converted to km, rad, and sec. The only
valid inputs for units are [m, km, mile, rad, deg, sec, min, hour].
The field UnitDbl.value will contain the converted value. Use
the convert() method to get a specific type of units back.
= ERROR CONDITIONS
- If the input units are not in the allowed list, an error is thrown.
= INPUT VARIABLES
- value The numeric value of the UnitDbl.
- units The string name of the units the value is in.
"""
self.checkUnits(units)
data = self.allowed[units]
self._value = float(value * data[0])
self._units = data[1]
def convert(self, units):
"""Convert the UnitDbl to a specific set of units.
= ERROR CONDITIONS
- If the input units are not in the allowed list, an error is thrown.
= INPUT VARIABLES
- units The string name of the units to convert to.
= RETURN VALUE
- Returns the value of the UnitDbl in the requested units as a floating
point number.
"""
if self._units == units:
return self._value
self.checkUnits(units)
data = self.allowed[units]
if self._units != data[1]:
msg = "Error trying to convert to different units.\n" \
" Invalid conversion requested.\n" \
" UnitDbl: %s\n" \
" Units: %s\n" % (str(self), units)
raise ValueError(msg)
return self._value / data[0]
def __abs__(self):
"""Return the absolute value of this UnitDbl."""
return UnitDbl(abs(self._value), self._units)
def __neg__(self):
"""Return the negative value of this UnitDbl."""
return UnitDbl(-self._value, self._units)
def __bool__(self):
"""Return the truth value of a UnitDbl."""
return bool(self._value)
def __eq__(self, rhs):
return self._cmp(rhs, operator.eq)
def __ne__(self, rhs):
return self._cmp(rhs, operator.ne)
def __lt__(self, rhs):
return self._cmp(rhs, operator.lt)
def __le__(self, rhs):
return self._cmp(rhs, operator.le)
def __gt__(self, rhs):
return self._cmp(rhs, operator.gt)
def __ge__(self, rhs):
return self._cmp(rhs, operator.ge)
def _cmp(self, rhs, op):
"""Compare two UnitDbl's.
= ERROR CONDITIONS
- If the input rhs units are not the same as our units,
an error is thrown.
= INPUT VARIABLES
- rhs The UnitDbl to compare against.
- op The function to do the comparison
= RETURN VALUE
- Returns op(self, rhs)
"""
self.checkSameUnits(rhs, "compare")
return op(self._value, rhs._value)
def __add__(self, rhs):
"""Add two UnitDbl's.
= ERROR CONDITIONS
- If the input rhs units are not the same as our units,
an error is thrown.
= INPUT VARIABLES
- rhs The UnitDbl to add.
= RETURN VALUE
- Returns the sum of ourselves and the input UnitDbl.
"""
self.checkSameUnits(rhs, "add")
return UnitDbl(self._value + rhs._value, self._units)
def __sub__(self, rhs):
"""Subtract two UnitDbl's.
= ERROR CONDITIONS
- If the input rhs units are not the same as our units,
an error is thrown.
= INPUT VARIABLES
- rhs The UnitDbl to subtract.
= RETURN VALUE
- Returns the difference of ourselves and the input UnitDbl.
"""
self.checkSameUnits(rhs, "subtract")
return UnitDbl(self._value - rhs._value, self._units)
def __mul__(self, rhs):
"""Scale a UnitDbl by a value.
= INPUT VARIABLES
- rhs The scalar to multiply by.
= RETURN VALUE
- Returns the scaled UnitDbl.
"""
return UnitDbl(self._value * rhs, self._units)
def __rmul__(self, lhs):
"""Scale a UnitDbl by a value.
= INPUT VARIABLES
- lhs The scalar to multiply by.
= RETURN VALUE
- Returns the scaled UnitDbl.
"""
return UnitDbl(self._value * lhs, self._units)
def __div__(self, rhs):
"""Divide a UnitDbl by a value.
= INPUT VARIABLES
- rhs The scalar to divide by.
= RETURN VALUE
- Returns the scaled UnitDbl.
"""
return UnitDbl(self._value / rhs, self._units)
def __str__(self):
"""Print the UnitDbl."""
return "%g *%s" % (self._value, self._units)
def __repr__(self):
"""Print the UnitDbl."""
return "UnitDbl(%g, '%s')" % (self._value, self._units)
def type(self):
"""Return the type of UnitDbl data."""
return self._types[self._units]
def range(start, stop, step=None):
"""Generate a range of UnitDbl objects.
Similar to the Python range() method. Returns the range [
start, stop) at the requested step. Each element will be a
UnitDbl object.
= INPUT VARIABLES
- start The starting value of the range.
- stop The stop value of the range.
- step Optional step to use. If set to None, then a UnitDbl of
value 1 w/ the units of the start is used.
= RETURN VALUE
- Returns a list containing the requested UnitDbl values.
"""
if step is None:
step = UnitDbl(1, start._units)
elems = []
i = 0
while True:
d = start + i * step
if d >= stop:
break
elems.append(d)
i += 1
return elems
range = staticmethod(range)
def checkUnits(self, units):
"""Check to see if some units are valid.
= ERROR CONDITIONS
- If the input units are not in the allowed list, an error is thrown.
= INPUT VARIABLES
- units The string name of the units to check.
"""
if units not in self.allowed:
raise ValueError("Input units '%s' are not one of the supported "
"types of %s" % (
units, list(self.allowed.keys())))
def checkSameUnits(self, rhs, func):
"""Check to see if units are the same.
= ERROR CONDITIONS
- If the units of the rhs UnitDbl are not the same as our units,
an error is thrown.
= INPUT VARIABLES
- rhs The UnitDbl to check for the same units
- func The name of the function doing the check.
"""
if self._units != rhs._units:
msg = "Cannot %s units of different types.\n" \
"LHS: %s\n" \
"RHS: %s" % (func, self._units, rhs._units)
raise ValueError(msg)