numpy.sin¶

numpy.sin(x,/,out=None,*,where=True,casting='same_kind',order='K',dtype=None,subok=True[,signature,extobj]) = <ufunc 'sin'>¶

Trigonometric sine, element-wise.

Parameters:

x:array_like Angle, in radians (2 \pi rad equals 360 degrees). out:ndarray, None, or tuple of ndarray and None, optional A location into which the result is stored. If provided, it must havea shape that the inputs broadcast to. If not provided orNone,a freshly-allocated array is returned. A tuple (possible only as akeyword 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, valuesof False indicate to leave the value in the output alone. **kwargs For other keyword-only arguments, see theufunc docs.

Returns:

y:array_like The sine of each element of x.This is a scalar ifx is a scalar.

See also

arcsin,sinh,cos

Notes

The sine is one of the fundamental functions of trigonometry (themathematical study of triangles). Consider a circle of radius 1centered on the origin. A ray comes in from the+x axis, makesan angle at the origin (measured counter-clockwise from that axis), anddeparts from the origin. They coordinate of the outgoingray’s intersection with the unit circle is the sine of that angle. Itranges from -1 forx=3\pi / 2 to +1 for\pi / 2. Thefunction has zeroes where the angle is a multiple of\pi.Sines of angles between\pi and2\pi are negative.The numerous properties of the sine and related functions are includedin any standard trigonometry text.

Examples

Print sine of one angle:

>>>np.sin(np.pi/2.)1.0

Print sines of an array of angles given in degrees:

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

Plot the sine function:

>>>importmatplotlib.pylabasplt>>>x=np.linspace(-np.pi,np.pi,201)>>>plt.plot(x,np.sin(x))>>>plt.xlabel('Angle [rad]')>>>plt.ylabel('sin(x)')>>>plt.axis('tight')>>>plt.show()