FunctionQuantity¶

class
astropy.units.
FunctionQuantity
[source]¶ Bases:
astropy.units.quantity.Quantity
A representation of a (scaled) function of a number with a unit.
Function quantities are quantities whose units are functions containing a physical unit, such as dB(mW). Most of the arithmetic operations on function quantities are defined in this base class.
While instantiation is also defined here, this class should not be instantiated directly. Rather, subclasses should be made which have
_unit_class
pointing back to the corresponding function unit class.Parameters:  value : number, sequence of convertible items,
Quantity
, orFunctionQuantity
The numerical value of the function quantity. If a number or a
Quantity
with a function 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 function 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, it is determined from the input, except that any input that cannot represent float (integer and bool) is converted to float.
 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.) order : {‘C’, ‘F’, ‘A’}, optional
Specify the order of the array. As in
array
. Ignored if the input does not need to be converted andcopy=False
. subok : bool, optional
If
False
(default), the returned array will be forced to be of the class used. Otherwise, subclasses will be passed through. ndmin : int, optional
Specifies the minimum number of dimensions that the resulting array should have. Ones will be prepended to the shape as needed to meet this requirement. This parameter is ignored if the input is a
Quantity
andcopy=False
.
Raises:  TypeError
If the value provided is not a Python numeric type.
 TypeError
If the unit provided is not a
FunctionUnitBase
orUnit
object, or a parseable string unit.
Attributes Summary
cgs
Return a copy with the physical unit in CGS units. physical
The physical quantity corresponding the function one. si
Return a copy with the physical unit in SI units. Methods Summary
clip
([min, max, out])Return an array whose values are limited to [min, max]
.cumsum
([axis, dtype, out])Return the cumulative sum of the elements along the given axis. decompose
(self[, bases])Generate a new FunctionQuantity
with the physical unit decomposed.max
([axis, out, keepdims])Return the maximum along a given axis. min
([axis, out, keepdims])Return the minimum along a given axis. sum
([axis, dtype, out, keepdims])Return the sum of the array elements over the given axis. Attributes Documentation

cgs
¶ Return a copy with the physical unit in CGS units.

physical
¶ The physical quantity corresponding the function one.

si
¶ Return a copy with the physical unit in SI units.
Methods Documentation

clip
(min=None, max=None, out=None)[source]¶ Return an array whose values are limited to
[min, max]
. One of max or min must be given.Refer to
numpy.clip
for full documentation.See also
numpy.clip
 equivalent function

cumsum
(axis=None, dtype=None, out=None)[source]¶ Return the cumulative sum of the elements along the given axis.
Refer to
numpy.cumsum
for full documentation.See also
numpy.cumsum
 equivalent function

decompose
(self, bases=[])[source]¶ Generate a new
FunctionQuantity
with the physical unit decomposed.For details, see
decompose
.

max
(axis=None, out=None, keepdims=False)[source]¶ Return the maximum along a given axis.
Refer to
numpy.amax
for full documentation.See also
numpy.amax
 equivalent function

min
(axis=None, out=None, keepdims=False)[source]¶ Return the minimum along a given axis.
Refer to
numpy.amin
for full documentation.See also
numpy.amin
 equivalent function
 value : number, sequence of convertible items,