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.. Copyright (c) 2016, Johan Mabille, Sylvain Corlay and Wolf Vollprecht
Distributed under the terms of the BSD 3-Clause License.
The full license is in the file LICENSE, distributed with this software.
Operators
=========
Operations and functions of *xtensor* are not evaluated until they are assigned.
In the following, ``e1``, ``e2`` and ``e3`` can be arbitrary tensor expressions.
The results of operations and functions are assigned to :cpp:type:`xt::xarray` in the examples,
but that could be any other container (or even views). To keep an unevaluated
operator / function, assign to an ``auto`` variable:
.. code::
auto res = e1 + e2;
See :ref:`lazy-evaluation` for more details on unevaluated expressions.
Arithmetic operators
--------------------
.. code::
xt::xarray<double> res0 = -e1;
xt::xarray<double> res1 = e1 + e2;
xt::xarray<double> res2 = e1 - e2;
xt::xarray<double> res3 = e1 * e2;
xt::xarray<double> res4 = e1 / e2;
xt::xarray<double> res5 = e1 % e2;
res1 += e2;
res2 -= e2;
res3 *= e2;
res4 /= e2;
res5 %= e2;
Bitwise operators
-----------------
.. code::
xt::xarray<double> res0 = e1 & e2;
xt::xarray<double> res1 = e1 | e2;
xt::xarray<double> res2 = e1 ^ e2;
xt::xarray<double> res3 = ~e1;
res0 &= e2;
res1 |= e2;
Logical operators
-----------------
.. code::
xt::xarray<double> res0 = e1 && e2;
xt::xarray<double> res1 = e1 || e2;
xt::xarray<double> res2 = !e1;
bool res3 = any(e1);
bool res4 = all(e1);
xt::xarray<double> res5 = where(e1, e2, e3);
Comparison operators
--------------------
Comparison operators return expressions performing element-wise
comparison:
.. code::
xt::xarray<double> res0 = e1 < e2;
xt::xarray<double> res1 = e1 > e2;
xt::xarray<double> res2 = e1 <= e2;
xt::xarray<double> res3 = e1 >= e2;
xt::xarray<double> res4 = xt::equal(e1, e2);
xt::xarray<double> res5 = xt::not_equal(e1, e2);
Except for equality and inequality operators which performs traditional
comparison and return a boolean:
.. code::
bool res0 = e1 == e2; // true if all elements in e1 equal those in e2
bool res1 = e1 != e2;
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