LogQuantity¶
-
class
astropy.units.
LogQuantity
[source] [edit on github]¶ Bases:
astropy.units.function.FunctionQuantity
A representation of a (scaled) logarithm of a number with a unit
Parameters: - value : number,
Quantity
,LogQuantity
, or sequence of convertible items. The numerical value of the logarithmic quantity. If a number or a
Quantity
with a logarithmic unit, it will be converted tounit
and the physical unit will be inferred fromunit
. If aQuantity
with just a physical unit, it will converted to the logarithmic unit, after, if necessary, converting it to the physical unit inferred fromunit
.- unit : string,
UnitBase
orFunctionUnitBase
instance, optional For an
FunctionUnitBase
instance, the physical unit will be taken from it; for other input, it will be inferred fromvalue
. By default,unit
is set by the subclass.- dtype :
dtype
, optional The
dtype
of the resulting Numpy array or scalar that will hold the value. If not provided, is is determined automatically from the input value.- copy : bool, optional
If
True
(default), then the value is copied. Otherwise, a copy will only be made if__array__
returns a copy, if value is a nested sequence, or if a copy is needed to satisfy an explicitly givendtype
. (TheFalse
option is intended mostly for internal use, to speed up initialization where a copy is known to have been made. Use with care.)
Examples
Typically, use is made of an
FunctionQuantity
subclass, as in:>>> import astropy.units as u >>> u.Magnitude(-2.5) <Magnitude -2.5 mag> >>> u.Magnitude(10.*u.count/u.second) <Magnitude -2.5 mag(ct / s)> >>> u.Decibel(1.*u.W, u.DecibelUnit(u.mW)) <Decibel 30. dB(mW)>
Methods Summary
diff
([n, axis])ediff1d
([to_end, to_begin])ptp
([axis, out, keepdims])Peak to peak (maximum - minimum) value along a given axis. std
([axis, dtype, out, ddof, keepdims])Returns the standard deviation of the array elements along given axis. var
([axis, dtype, out, ddof, keepdims])Returns the variance of the array elements, along given axis. Methods Documentation
-
diff
(n=1, axis=-1)[source] [edit on github]¶
-
ediff1d
(to_end=None, to_begin=None)[source] [edit on github]¶
-
ptp
(axis=None, out=None, keepdims=False)[source] [edit on github]¶ Peak to peak (maximum - minimum) value along a given axis.
Refer to
numpy.ptp
for full documentation.See also
numpy.ptp
- equivalent function
-
std
(axis=None, dtype=None, out=None, ddof=0, keepdims=False)[source] [edit on github]¶ Returns the standard deviation of the array elements along given axis.
Refer to
numpy.std
for full documentation.See also
numpy.std
- equivalent function
-
var
(axis=None, dtype=None, out=None, ddof=0, keepdims=False)[source] [edit on github]¶ Returns the variance of the array elements, along given axis.
Refer to
numpy.var
for full documentation.See also
numpy.var
- equivalent function
- value : number,