numpy.arcsin(x[, out]) =
Inverse sine, element-wise.
Parameters: |
x : array_like
out : ndarray, optional Array of the same shape as |
---|---|
Returns: |
angle : ndarray The inverse sine of each element in |
arcsin
is a multivalued function: for each x
there are infinitely many numbers z
such that . The convention is to return the angle z
whose 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 nan
and sets the invalid
floating 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 asin
or sin^{-1}.
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
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https://docs.scipy.org/doc/numpy-1.12.0/reference/generated/numpy.arcsin.html