diff options
Diffstat (limited to 'numpy/lib/function_base.py')
| -rw-r--r-- | numpy/lib/function_base.py | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py index cd8862c94..b530f0aa1 100644 --- a/numpy/lib/function_base.py +++ b/numpy/lib/function_base.py @@ -3193,25 +3193,18 @@ def i0(x): """ Modified Bessel function of the first kind, order 0. - Usually denoted :math:`I_0`. This function does broadcast, but will *not* - "up-cast" int dtype arguments unless accompanied by at least one float or - complex dtype argument (see Raises below). + Usually denoted :math:`I_0`. Parameters ---------- - x : array_like, dtype float or complex + x : array_like of float Argument of the Bessel function. Returns ------- - out : ndarray, shape = x.shape, dtype = x.dtype + out : ndarray, shape = x.shape, dtype = float The modified Bessel function evaluated at each of the elements of `x`. - Raises - ------ - TypeError: array cannot be safely cast to required type - If argument consists exclusively of int dtypes. - See Also -------- scipy.special.i0, scipy.special.iv, scipy.special.ive @@ -3241,12 +3234,16 @@ def i0(x): Examples -------- >>> np.i0(0.) - array(1.0) # may vary - >>> np.i0([0., 1. + 2j]) - array([ 1.00000000+0.j , 0.18785373+0.64616944j]) # may vary + array(1.0) + >>> np.i0([0, 1, 2, 3]) + array([1. , 1.26606588, 2.2795853 , 4.88079259]) """ x = np.asanyarray(x) + if x.dtype.kind == 'c': + raise TypeError("i0 not supported for complex values") + if x.dtype.kind != 'f': + x = x.astype(float) x = np.abs(x) return piecewise(x, [x <= 8.0], [_i0_1, _i0_2]) |