# Source code for mars.tensor.arithmetic.sin

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 1999-2021 Alibaba Group Holding Ltd.
#
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#
# Unless required by applicable law or agreed to in writing, software
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and

import numpy as np

from ... import opcodes as OperandDef
from ..utils import infer_dtype
from .core import TensorUnaryOp
from .utils import arithmetic_operand

@arithmetic_operand(sparse_mode="unary")
class TensorSin(TensorUnaryOp):
_op_type_ = OperandDef.SIN
_func_name = "sin"

[docs]@infer_dtype(np.sin)
def sin(x, out=None, where=None, **kwargs):
r"""
Trigonometric sine, element-wise.

Parameters
----------
x : array_like
Angle, in radians (:math:2 \pi rad equals 360 degrees).
out : Tensor, None, or tuple of Tensor and None, optional
A location into which the result is stored. If provided, it must have
a shape that the inputs broadcast to. If not provided or None,
a freshly-allocated tensor is returned. A tuple (possible only as a
keyword argument) must have length equal to the number of outputs.
where : array_like, optional
Values of True indicate to calculate the ufunc at that position, values
of False indicate to leave the value in the output alone.
**kwargs

Returns
-------
y : array_like
The sine of each element of x.

--------
arcsin, sinh, cos

Notes
-----
The sine is one of the fundamental functions of trigonometry (the
mathematical study of triangles).  Consider a circle of radius 1
centered on the origin.  A ray comes in from the :math:+x axis, makes
an angle at the origin (measured counter-clockwise from that axis), and
departs from the origin.  The :math:y coordinate of the outgoing
ray's intersection with the unit circle is the sine of that angle.  It
ranges from -1 for :math:x=3\pi / 2 to +1 for :math:\pi / 2.  The
function has zeroes where the angle is a multiple of :math:\pi.
Sines of angles between :math:\pi and :math:2\pi are negative.
The numerous properties of the sine and related functions are included
in any standard trigonometry text.

Examples
--------
Print sine of one angle:

>>> import mars.tensor as mt

>>> mt.sin(mt.pi/2.).execute()
1.0

Print sines of an array of angles given in degrees:

>>> mt.sin(mt.array((0., 30., 45., 60., 90.)) * mt.pi / 180. ).execute()
array([ 0.        ,  0.5       ,  0.70710678,  0.8660254 ,  1.        ])

Plot the sine function:

>>> import matplotlib.pylab as plt
>>> x = mt.linspace(-mt.pi, mt.pi, 201)
>>> plt.plot(x.execute(), mt.sin(x).execute())