nifty8.multi_field module

class MultiField(domain, val)

Bases: Operator

Transforms values defined on one domain into values defined on another domain, and can also provide the Jacobian.

__init__(domain, val)

The discrete representation of a continuous field over a sum space.

Parameters:

• domain (MultiDomain)

• val (tuple containing Field entries)

clip(a_min=None, a_max=None)

conjugate()

property domain

The domain on which the Operator’s input Field is defined.

Returns:

domain

Return type:

DomainTuple or MultiDomain

property dtype

extract(subset)

extract_by_keys(keys)

extract_part(subset)

flexible_addsub(other, neg)

Merges two MultiFields on potentially different MultiDomains.

Parameters:

• other (nifty8.multi_field.MultiField) – the partner Field

• neg (bool or dict) – if True, the partner field is subtracted, otherwise added

Returns:

This MultiField’s domain is the union of the input fields’ domains. The values are the sum (or difference, if neg==True) of the fields in self and other. If a field is not present, it is assumed to have an uniform value of zero.

Return type:

MultiField

static from_dict(dct, domain=None)

static from_random(domain, random_type='normal', dtype=<class 'numpy.float64'>, **kwargs)

Draws a random multi-field with the given parameters.

Parameters:

• random_type ('pm1', 'normal', or 'uniform') – The random distribution to use.

• domain (DomainTuple) – The domain of the output random Field.

• dtype (type) – The datatype of the output random Field. If the datatype is complex, each real an imaginary part have variance 1.

Returns:

The newly created MultiField.

Return type:

MultiField

Notes

The individual fields within this multi-field will be drawn in alphabetical order of the multi-field’s domain keys. As a consequence, renaming these keys may cause the multi-field to be filled with different random numbers, even for the same initial RNG state.

static from_raw(domain, arr)

static full(domain, val)

property imag

The imaginary part of the multi field

Type:

MultiField

items()

keys()

norm(ord=2)

Computes the norm of the field values.

Parameters:

ord (int, default=2) – accepted values: 1, 2, …, np.inf

Returns:

norm – The norm of the field values.

Return type:

float

ptw(op, *args, **kwargs)

ptw_with_deriv(op, *args, **kwargs)

property real

The real part of the multi field

Type:

MultiField

s_all()

s_any()

s_sum()

Computes the sum all field values.

Returns:

norm – The sum of the field values.

Return type:

float

s_vdot(x)

property size

Computes the overall degrees of freedom.

Returns:

size – The sum of the size of the individual fields

Return type:

int

to_dict()

static union(fields, domain=None)

Returns the union of its input fields.

Parameters:

• fields (iterable of nifty8.multi_field.MultiField) – The set of input fields. Their domains need not be identical.

• domain (MultiDomain or None) – If supplied, this will be the domain of the resulting field. Providing this domain will accelerate the function.

Returns:

The union of the input fields

Return type:

MultiField

Notes

If the same key occurs more than once in the input fields, the value associated with the last occurrence will be put into the output. No summation is performed!

unite(other)

Merges two MultiFields on potentially different MultiDomains.

Parameters:

other (nifty8.multi_field.MultiField) – the partner Field

Returns:

This MultiField’s domain is the union of the input fields’ domains. The values are the sum of the fields in self and other. If a field is not present, it is assumed to have an uniform value of zero.

Return type:

MultiField

property val

The numerical value associated with this object For “pure” operators this is None. For Field-like objects this is a numpy.ndarray or a dictionary of numpy.ndarray`s mathcing the object’s `target.

Returns:

None or numpy.ndarray or dictionary of np.ndarrays

Return type:

the numerical value

val_rw()

values()

vdot(x)

func(op)