# Quantity class

(Shortest import: `from brian2 import Quantity)`

class brian2.units.fundamentalunits.Quantity(arr, dim=None, dtype=None, copy=False, force_quantity=False)[source]

Bases: `ndarray`

A number with an associated physical dimension. In most cases, it is not necessary to create a Quantity object by hand, instead use multiplication and division of numbers with the constant unit names `second`, `kilogram`, etc.

Attributes

 `dim` `dimensions` The physical dimensions of this quantity. `is_dimensionless` Whether this is a dimensionless quantity.

Methods

 `all`([axis, out, keepdims, where]) Returns True if all elements evaluate to True. `any`([axis, out, keepdims, where]) Returns True if any of the elements of `a` evaluate to True. `argmax`([axis, out, keepdims]) Return indices of the maximum values along the given axis. `argmin`([axis, out, keepdims]) Return indices of the minimum values along the given axis. `argsort`([axis, kind, order]) Returns the indices that would sort this array. `clip`([min, max, out]) Return an array whose values are limited to `[min, max]`. `cumprod`([axis, dtype, out]) Return the cumulative product of the elements along the given axis. `cumsum`([axis, dtype, out]) Return the cumulative sum of the elements along the given axis. `diagonal`([offset, axis1, axis2]) Return specified diagonals. `dot`(other, **kwds) `fill`(value) Fill the array with a scalar value. `get_best_unit`(*regs) Return the best unit for this `Quantity`. Return whether this object has the same dimensions as another. `in_best_unit`([precision, python_code]) Represent the quantity in the "best" unit. `in_unit`(u[, precision, python_code]) Represent the quantity in a given unit. `item`(*args) Overwritten to assure that the returned element retains its unit. `max`([axis, out, keepdims, initial, where]) Return the maximum along a given axis. `mean`([axis, dtype, out, keepdims, where]) Returns the average of the array elements along given axis. `min`([axis, out, keepdims, initial, where]) Return the minimum along a given axis. Return the indices of the elements that are non-zero. `prod`([axis, dtype, out, keepdims, initial, ...]) Return the product of the array elements over the given axis `ptp`([axis, out, keepdims]) Peak to peak (maximum - minimum) value along a given axis. `put`(indices, values[, mode]) Set `a.flat[n] = values[n]` for all `n` in indices. `ravel`([order]) Return a flattened array. `round`([decimals, out]) Return `a` with each element rounded to the given number of decimals. `searchsorted`(v[, side, sorter]) Find indices where elements of v should be inserted in a to maintain order. `std`([axis, dtype, out, ddof, keepdims, where]) Returns the standard deviation of the array elements along given axis. `sum`([axis, dtype, out, keepdims, initial, where]) Return the sum of the array elements over the given axis. Convert the array into a list. `trace`([offset, axis1, axis2, dtype, out]) Return the sum along diagonals of the array. `var`([axis, dtype, out, ddof, keepdims, where]) Returns the variance of the array elements, along given axis. `with_dimensions`(value, *args, **keywords) Create a `Quantity` object with dim.

Details

dim
dimensions

The physical dimensions of this quantity.

is_dimensionless

Whether this is a dimensionless quantity.

all(axis=None, out=None, keepdims=False, *, where=True)

Returns True if all elements evaluate to True.

Refer to `numpy.all` for full documentation.

any(axis=None, out=None, keepdims=False, *, where=True)

Returns True if any of the elements of `a` evaluate to True.

Refer to `numpy.any` for full documentation.

argmax(axis=None, out=None, *, keepdims=False)

Return indices of the maximum values along the given axis.

Refer to `numpy.argmax` for full documentation.

argmin(axis=None, out=None, *, keepdims=False)

Return indices of the minimum values along the given axis.

Refer to `numpy.argmin` for detailed documentation.

argsort(axis=-1, kind=None, order=None)

Returns the indices that would sort this array.

Refer to `numpy.argsort` for full documentation.

clip(min=None, max=None, out=None, **kwargs)[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.

cumprod(axis=None, dtype=None, out=None)[source]

Return the cumulative product of the elements along the given axis.

Refer to `numpy.cumprod` for full documentation.

cumsum(axis=None, dtype=None, out=None)

Return the cumulative sum of the elements along the given axis.

Refer to `numpy.cumsum` for full documentation.

diagonal(offset=0, axis1=0, axis2=1)

Return specified diagonals. In NumPy 1.9 the returned array is a read-only view instead of a copy as in previous NumPy versions. In a future version the read-only restriction will be removed.

Refer to `numpy.diagonal()` for full documentation.

dot(other, **kwds)[source]
fill(value)[source]

Fill the array with a scalar value.

get_best_unit(*regs)[source]

Return the best unit for this `Quantity`.

has_same_dimensions(other)[source]

Return whether this object has the same dimensions as another.

in_best_unit(precision=None, python_code=False, *regs)[source]

Represent the quantity in the “best” unit.

in_unit(u, precision=None, python_code=False)[source]

Represent the quantity in a given unit. If `python_code` is `True`, this will return valid python code, i.e. a string like `5.0 * um ** 2` instead of `5.0 um^2`

item(*args)[source]

Overwritten to assure that the returned element retains its unit.

max(axis=None, out=None, keepdims=False, initial=<no value>, where=True)

Return the maximum along a given axis.

Refer to `numpy.amax` for full documentation.

mean(axis=None, dtype=None, out=None, keepdims=False, *, where=True)

Returns the average of the array elements along given axis.

Refer to `numpy.mean` for full documentation.

min(axis=None, out=None, keepdims=False, initial=<no value>, where=True)

Return the minimum along a given axis.

Refer to `numpy.amin` for full documentation.

nonzero()

Return the indices of the elements that are non-zero.

Refer to `numpy.nonzero` for full documentation.

prod(axis=None, dtype=None, out=None, keepdims=False, initial=1, where=True)[source]

Return the product of the array elements over the given axis

Refer to `numpy.prod` for full documentation.

ptp(axis=None, out=None, keepdims=False)

Peak to peak (maximum - minimum) value along a given axis.

Refer to `numpy.ptp` for full documentation.

put(indices, values, mode='raise')[source]

Set `a.flat[n] = values[n]` for all `n` in indices.

Refer to `numpy.put` for full documentation.

ravel([order])[source]

Return a flattened array.

Refer to `numpy.ravel` for full documentation.

round(decimals=0, out=None)

Return `a` with each element rounded to the given number of decimals.

Refer to `numpy.around` for full documentation.

searchsorted(v, side='left', sorter=None)[source]

Find indices where elements of v should be inserted in a to maintain order.

For full documentation, see `numpy.searchsorted`

std(axis=None, dtype=None, out=None, ddof=0, keepdims=False, *, where=True)

Returns the standard deviation of the array elements along given axis.

Refer to `numpy.std` for full documentation.

sum(axis=None, dtype=None, out=None, keepdims=False, initial=0, where=True)

Return the sum of the array elements over the given axis.

Refer to `numpy.sum` for full documentation.

tolist()[source]

Convert the array into a list.

trace(offset=0, axis1=0, axis2=1, dtype=None, out=None)

Return the sum along diagonals of the array.

Refer to `numpy.trace` for full documentation.

var(axis=None, dtype=None, out=None, ddof=0, keepdims=False, *, where=True)

Returns the variance of the array elements, along given axis.

Refer to `numpy.var` for full documentation.

static with_dimensions(value, *args, **keywords)[source]

Create a `Quantity` object with dim.