numpy.sin¶
- numpy.sin(x[, out]) = <ufunc 'sin'>¶
Trigonometric sine, element-wise.
Parameters: x : array_like
Angle, in radians ( rad equals 360 degrees).
Returns: y : array_like
The sine of each element of x.
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 axis, makes an angle at the origin (measured counter-clockwise from that axis), and departs from the origin. The coordinate of the outgoing ray’s intersection with the unit circle is the sine of that angle. It ranges from -1 for to +1 for The function has zeroes where the angle is a multiple of . Sines of angles between and are negative. The numerous properties of the sine and related functions are included in 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:
>>> import matplotlib.pylab as plt >>> 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()
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