mirror of
https://github.com/triqs/dft_tools
synced 2024-11-01 03:33:50 +01:00
99 lines
5.1 KiB
ReStructuredText
99 lines
5.1 KiB
ReStructuredText
.. highlight:: c
|
|
|
|
vector and vector_view
|
|
============================
|
|
|
|
vector and vector_view :
|
|
|
|
* are the class for a vector and the corresponding view.
|
|
* model the :ref:`HasImmutableArrayInterface` concept.
|
|
|
|
|
|
Template parameters
|
|
----------------------------
|
|
|
|
* The classes have two template parameters.
|
|
|
|
.. code-block:: c
|
|
|
|
template <typename ValueType, typename Opt = Option::Default> class vector_view;
|
|
template <typename ValueType, typename Opt = Option::Default> class vector;
|
|
|
|
============================ ================================== ========================== ====================================================================
|
|
Template parameter Accepted type Access in the class Meaning
|
|
============================ ================================== ========================== ====================================================================
|
|
ValueType normally a scalar, but any default value_type The type of the element of the vector
|
|
constructible type (?).
|
|
Opt Option::options< ...> opt_type Compile time options, see below.
|
|
============================ ================================== ========================== ====================================================================
|
|
|
|
Options template parameters are described :ref:`here <option_template>`.
|
|
The memory order is obviously useless here...
|
|
|
|
.. _vector_constructors:
|
|
|
|
Constructors
|
|
-----------------
|
|
|
|
Intentionally, vector and vector_view have only a few constructors :
|
|
|
|
========================================== ===========================================================================================
|
|
Constructors of vector Comments
|
|
========================================== ===========================================================================================
|
|
vector() - empty vector of size 0
|
|
vector(size_t) - from the dimension. Does **NOT** initialize the elements of the vector to 0 !
|
|
vector(const vector &) - copy construction
|
|
vector (PyObject * X) - Construct a new vector from the data of the Python object X.
|
|
NB : X is a borrowed reference, vector does affect its counting reference.
|
|
- it takes a **copy** of the data of X (or of numpy(X)) into C++.
|
|
- X is first transformed into a numpy by the python numpy lib itself
|
|
(as if you call numpy.array(X)) if X is not a numpy array or an array of the wrong type
|
|
(e.g. you construct an vector<double> from a numpy of int....).
|
|
vector(const T & X) - Type T models the :ref:`HasImmutableArrayInterface` concept.
|
|
- X must have the appropriate domain (checked at compile time).
|
|
- Constructs a new vector of domain X.domain() and fills it with evaluation of X.
|
|
========================================== ===========================================================================================
|
|
|
|
* Examples ::
|
|
|
|
vector<int> A(10,2);
|
|
A()=0; // init A to 0
|
|
|
|
.. warning::
|
|
The constructor from the dimensions does **NOT** initialize the vector to 0
|
|
(because it may not be optimal).
|
|
If needed, do it explicitely by `a()=0`;
|
|
|
|
Constructors of vector_views
|
|
----------------------------------------------
|
|
|
|
Automatic construction
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
vector_view are normally automatically constructed by making (partial) views, ref:`Slicing`, e.g. ::
|
|
|
|
tqa::vector<int> A(2,2);
|
|
A(range(),2) ; // --> this makes a view...
|
|
A() ; // --> this makes a view over the full array
|
|
|
|
|
|
Explicit construction
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
To explicitly make a view of an vector, use make_view ::
|
|
|
|
vector<int> A(2,2);
|
|
make_view(A) //-> a view...
|
|
make_view(A) = 13 ; // to assign e.g.
|
|
|
|
|
|
|
|
====================================================================== ===========================================================================================================
|
|
Constructors of vector_view Comments
|
|
====================================================================== ===========================================================================================================
|
|
vector_view(const array_view &) - Copy construction (shallow copy)
|
|
vector_view(const T & X) - `[Advanced]` T is any type such that X.indexmap() and X.storage() can be used to construct a view.
|
|
====================================================================== ===========================================================================================================
|
|
|
|
|