diff options
Diffstat (limited to 'numpy/lib/function_base.py')
| -rw-r--r-- | numpy/lib/function_base.py | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py index 4172c26b5..df9c7f177 100644 --- a/numpy/lib/function_base.py +++ b/numpy/lib/function_base.py @@ -1225,9 +1225,9 @@ def piecewise(x, condlist, funclist, *args, **kw): Parameters ---------- - x : ndarray + x : ndarray or scalar The input domain. - condlist : list of bool arrays + condlist : list of bool arrays or bool scalars Each boolean array corresponds to a function in `funclist`. Wherever `condlist[i]` is True, `funclist[i](x)` is used as the output value. @@ -1296,12 +1296,21 @@ def piecewise(x, condlist, funclist, *args, **kw): >>> np.piecewise(x, [x < 0, x >= 0], [lambda x: -x, lambda x: x]) array([ 2.5, 1.5, 0.5, 0.5, 1.5, 2.5]) + Apply the same function to a scalar value. + + >>> y = -2 + >>> np.piecewise(y, [y < 0, y >= 0], [lambda x: -x, lambda x: x]) + array(2) + """ x = asanyarray(x) n2 = len(funclist) if (isscalar(condlist) or not (isinstance(condlist[0], list) or isinstance(condlist[0], ndarray))): - condlist = [condlist] + if not isscalar(condlist) and x.size == 1 and x.ndim == 0: + condlist = [[c] for c in condlist] + else: + condlist = [condlist] condlist = array(condlist, dtype=bool) n = len(condlist) # This is a hack to work around problems with NumPy's @@ -1311,8 +1320,6 @@ def piecewise(x, condlist, funclist, *args, **kw): if x.ndim == 0: x = x[None] zerod = True - if condlist.shape[-1] != 1: - condlist = condlist.T if n == n2 - 1: # compute the "otherwise" condition. totlist = np.logical_or.reduce(condlist, axis=0) # Only able to stack vertically if the array is 1d or less |