diff options
Diffstat (limited to 'numpy/lib/ufunclike.py')
| -rw-r--r-- | numpy/lib/ufunclike.py | 77 |
1 files changed, 71 insertions, 6 deletions
diff --git a/numpy/lib/ufunclike.py b/numpy/lib/ufunclike.py index a8c2c1e25..37c38e94e 100644 --- a/numpy/lib/ufunclike.py +++ b/numpy/lib/ufunclike.py @@ -24,9 +24,30 @@ def fix(x, y=None): return y def isposinf(x, y=None): - """Return a boolean array y with y[i] True for x[i] = +Inf. + """ + Return True where x is +infinity, and False otherwise. + + Parameters + ---------- + x : array_like + The input array. + y : array_like + A boolean array with the same shape as `x` to store the result. + + Returns + ------- + y : ndarray + A boolean array where y[i] = True only if x[i] = +Inf. + + See Also + -------- + isneginf, isfinite + + Examples + -------- + >>> np.isposinf([-np.inf, 0., np.inf]) + array([ False, False, True], dtype=bool) - If y is an array, the result replaces the contents of y. """ if y is None: x = asarray(x) @@ -35,9 +56,30 @@ def isposinf(x, y=None): return y def isneginf(x, y=None): - """Return a boolean array y with y[i] True for x[i] = -Inf. + """ + Return True where x is -infinity, and False otherwise. + + Parameters + ---------- + x : array_like + The input array. + y : array_like + A boolean array with the same shape as `x` to store the result. + + Returns + ------- + y : ndarray + A boolean array where y[i] = True only if x[i] = -Inf. + + See Also + -------- + isposinf, isfinite + + Examples + -------- + >>> np.isneginf([-np.inf, 0., np.inf]) + array([ True, False, False], dtype=bool) - If y is an array, the result replaces the contents of y. """ if y is None: x = asarray(x) @@ -47,9 +89,32 @@ def isneginf(x, y=None): _log2 = umath.log(2) def log2(x, y=None): - """Returns the base 2 logarithm of x + """ + Return the base 2 logarithm. + + Parameters + ---------- + x : array_like + Input array. + y : array_like + Optional output array with the same shape as `x`. + + Returns + ------- + y : {ndarray, scalar} + The logarithm to the base 2 of `x` elementwise. + NaNs are returned where `x` is negative. + + + See Also + -------- + log, log1p, log10 + + Examples + -------- + >>> np.log2([-1,2,4]) + array([ NaN, 1., 2.]) - If y is an array, the result replaces the contents of y. """ x = asanyarray(x) if y is None: |