Vector

class psi4.core.Vector

Bases: pybind11_builtins.pybind11_object

Class for creating and manipulating vectors

Attributes Summary

name	The name of the Vector.
np	View with single irrep.
nph	View with irreps.
shape	Shape of the Psi4 data object.

Methods Summary

array_interface(self)
copy(self, arg0)	Returns a copy of the matrix
dim(self, h)	Returns the dimensions of the vector per irrep h
dimpi(self)	Returns the Dimension object
from_array([name, dim1, dim2])	Converts a numpy array or list of numpy arrays into a Psi4 Matrix (irreped if list).
from_list(x)
from_serial(json_data)	Converts serialized data to the correct Psi4 data type
get(*args, **kwargs)	Overloaded function.
get_block(self, slice)	Get a vector block
nirrep(self)	Returns the number of irreps
np_read(filename[, prefix])	Reads the data from a NumPy compress file.
np_write([filename, prefix])	Writes the irreped matrix to a NumPy zipped file.
print_out(self)	Prints the vector to the output file
scale(self, sc)	Scales the elements of a vector by sc
set(*args, **kwargs)	Overloaded function.
set_block(self, slice, block)	Set a vector block
to_array([copy, dense])	Converts a Psi4 Matrix or Vector to a NumPy array.
to_serial()	Converts an object with a .nph accessor to a serialized dictionary

Attributes Documentation

name

The name of the Vector. Used in printing.

np

View with single irrep.

nph

View with irreps.

shape

Shape of the Psi4 data object.

Methods Documentation

array_interface(self: psi4.core.Vector) → list

copy(self: psi4.core.Vector, arg0: psi4.core.Vector) → None

Returns a copy of the matrix

dim(self: psi4.core.Vector, h: int = 0) → int

Returns the dimensions of the vector per irrep h

dimpi(self: psi4.core.Vector) → psi4.core.Dimension

Returns the Dimension object

classmethod from_array(name='New Matrix', dim1=None, dim2=None)

Converts a numpy array or list of numpy arrays into a Psi4 Matrix (irreped if list).

Parameters

• arr (Union[ndarray, List[ndarray]]) – Numpy array or list of arrays to use as the data for a new core.Matrix

• name (str) – Name to give the new core.Matrix

• dim1 (Union[List, Tuple, Dimension, None]) – If a single dense numpy array is given, a dimension can be supplied to apply irreps to this array. Note that this discards all extra information given in the matrix besides the diagonal blocks determined by the passed dimension.

• dim2 (Optional[Dimension]) – Same as dim1 only if using a psi4.core.Dimension object.

Returns

Returns the given Psi4 object

Return type

Matrix or Vector

Notes

This is a generalized function to convert a NumPy array to a Psi4 object

Examples

>>> data = np.random.rand(20,1)
>>> vector = psi4.core.Matrix.from_array(data)

>>> irrep_data = [np.random.rand(2, 2), np.empty(shape=(0,3)), np.random.rand(4, 4)]
>>> matrix = psi4.core.Matrix.from_array(irrep_data)
>>> print(matrix.rowdim().to_tuple())
(2, 0, 4)

classmethod from_list(x)

classmethod from_serial(json_data)

Converts serialized data to the correct Psi4 data type

get(*args, **kwargs)

Overloaded function.

1. get(self: psi4.core.Vector, m: int) -> float

Returns a single element value located at m

2. get(self: psi4.core.Vector, h: int, m: int) -> float

Returns a single element value located at m in irrep h

get_block(self: psi4.core.Vector, slice: psi4.core.Slice) → psi4.core.Vector

Get a vector block

nirrep(self: psi4.core.Vector) → int

Returns the number of irreps

classmethod np_read(filename, prefix='')

Reads the data from a NumPy compress file.

np_write(filename=None, prefix='')

Writes the irreped matrix to a NumPy zipped file.

Can return the packed data for saving many matrices into the same file.

print_out(self: psi4.core.Vector) → None

Prints the vector to the output file

scale(self: psi4.core.Vector, sc: float) → None

Scales the elements of a vector by sc

set(*args, **kwargs)

Overloaded function.

1. set(self: psi4.core.Vector, m: int, val: float) -> None

Sets a single element value located at m

2. set(self: psi4.core.Vector, h: int, m: int, val: float) -> None

Sets a single element value located at m in irrep h

set_block(self: psi4.core.Vector, slice: psi4.core.Slice, block: psi4.core.Vector) → None

Set a vector block

to_array(copy=True, dense=False)

Converts a Psi4 Matrix or Vector to a NumPy array. Either copies the data or simply constructs a view.

Parameters

• matrix (Union[Matrix, Vector]) – Pointers to which Psi4 core class should be used in the construction.

• copy (bool) – Copy the data if True, return a view otherwise

• dense (bool) – Converts irreped Psi4 objects to diagonally blocked dense arrays if True. Returns a list of arrays otherwise.

Returns

Returns either a list of np.array’s or the base array depending on options.

Return type

numpy.ndarray

Notes

This is a generalized function to convert a Psi4 object to a NumPy array

Examples

>>> data = psi4.core.Matrix(3, 3)
>>> data.to_array()
[[ 0.  0.  0.]
 [ 0.  0.  0.]
 [ 0.  0.  0.]]

to_serial()

Converts an object with a .nph accessor to a serialized dictionary