tan function

(Shortest import: from brian2 import tan)

brian2.units.unitsafefunctions.tan(x[, out])

Compute tangent element-wise.

Equivalent to np.sin(x)/np.cos(x) element-wise.


x : array_like

Input array.

out : ndarray, optional

Output array of same shape as x.


y : ndarray

The corresponding tangent values.


ValueError: invalid return array shape
if out is provided and out.shape != x.shape (See Examples)


If out is provided, the function writes the result into it, and returns a reference to out. (See Examples)


M. Abramowitz and I. A. Stegun, Handbook of Mathematical Functions. New York, NY: Dover, 1972.


>>> from math import pi
>>> np.tan(np.array([-pi,pi/2,pi]))
array([  1.22460635e-16,   1.63317787e+16,  -1.22460635e-16])
>>> # Example of providing the optional output parameter illustrating
>>> # that what is returned is a reference to said parameter
>>> out2 = np.cos([0.1], out1)
>>> out2 is out1
>>> # Example of ValueError due to provision of shape mis-matched `out`
>>> np.cos(np.zeros((3,3)),np.zeros((2,2)))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid return array shape