from brian2 import arcsin)
Inverse sine, element-wise.
x : array_like
y-coordinate on the unit circle.
out : ndarray, optional
Array of the same shape as
x, in which to store the results. See
doc.ufuncs(Section “Output arguments”) for more details.
angle : ndarray
The inverse sine of each element in
x, in radians and in the closed interval
[-pi/2, pi/2]. If
xis a scalar, a scalar is returned, otherwise an array.
arcsin()is a multivalued function: for each
xthere are infinitely many numbers
zsuch that \(sin(z) = x\). The convention is to return the angle
zwhose real part lies in [-pi/2, pi/2].
For real-valued input data types, arcsin always returns real output. For each value that cannot be expressed as a real number or infinity, it yields
nanand sets the
invalidfloating point error flag.
For complex-valued input,
arcsin()is a complex analytic function that has, by convention, the branch cuts [-inf, -1] and [1, inf] and is continuous from above on the former and from below on the latter.
The inverse sine is also known as
Abramowitz, M. and Stegun, I. A., Handbook of Mathematical Functions, 10th printing, New York: Dover, 1964, pp. 79ff. http://www.math.sfu.ca/~cbm/aands/
>>> np.arcsin(1) # pi/2 1.5707963267948966 >>> np.arcsin(-1) # -pi/2 -1.5707963267948966 >>> np.arcsin(0) 0.0