-
numpy.arcsin(x[, out]) =
-
Inverse sine, element-wise.
Parameters: 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. Seedoc.ufuncs
(Section ?Output arguments?) for more details.Returns: angle : ndarray
The inverse sine of each element in
x
, in radians and in the closed interval[-pi/2, pi/2]
. Ifx
is a scalar, a scalar is returned, otherwise an array.Notes
arcsin
is a multivalued function: for eachx
there are infinitely many numbersz
such that . The convention is to return the anglez
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 theinvalid
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}.References
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/
Examples
>>> np.arcsin(1) # pi/2 1.5707963267948966 >>> np.arcsin(-1) # -pi/2 -1.5707963267948966 >>> np.arcsin(0) 0.0
numpy.arcsin()
2017-01-10 18:12:41
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