diff options
Diffstat (limited to 'numpy/lib/function_base.py')
| -rw-r--r-- | numpy/lib/function_base.py | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py index 75a39beaa..2992e92bb 100644 --- a/numpy/lib/function_base.py +++ b/numpy/lib/function_base.py @@ -305,12 +305,17 @@ def average(a, axis=None, weights=None, returned=False): Returns ------- - average, [sum_of_weights] : array_type or double - Return the average along the specified axis. When returned is `True`, + retval, [sum_of_weights] : array_type or double + Return the average along the specified axis. When `returned` is `True`, return a tuple with the average as the first element and the sum - of the weights as the second element. The return type is `Float` - if `a` is of integer type, otherwise it is of the same type as `a`. - `sum_of_weights` is of the same type as `average`. + of the weights as the second element. `sum_of_weights` is of the + same type as `retval`. The result dtype follows a genereal pattern. + If `weights` is None, the result dtype will be that of `a` , or ``float64`` + if `a` is integral. Otherwise, if `weights` is not None and `a` is non- + integral, the result type will be the type of lowest precision capable of + representing values of both `a` and `weights`. If `a` happens to be + integral, the previous rules still applies but the result dtype will + at least be ``float64``. Raises ------ @@ -327,6 +332,8 @@ def average(a, axis=None, weights=None, returned=False): ma.average : average for masked arrays -- useful if your data contains "missing" values + numpy.result_type : Returns the type that results from applying the + numpy type promotion rules to the arguments. Examples -------- @@ -346,10 +353,16 @@ def average(a, axis=None, weights=None, returned=False): >>> np.average(data, axis=1, weights=[1./4, 3./4]) array([ 0.75, 2.75, 4.75]) >>> np.average(data, weights=[1./4, 3./4]) + Traceback (most recent call last): ... TypeError: Axis must be specified when shapes of a and weights differ. - + + >>> a = np.ones(5, dtype=np.float128) + >>> w = np.ones(5, dtype=np.complex64) + >>> avg = np.average(a, weights=w) + >>> print(avg.dtype) + complex256 """ a = np.asanyarray(a) @@ -1769,8 +1782,8 @@ class vectorize(object): Generalized function class. Define a vectorized function which takes a nested sequence of objects or - numpy arrays as inputs and returns an single or tuple of numpy array as - output. The vectorized function evaluates `pyfunc` over successive tuples + numpy arrays as inputs and returns a single numpy array or a tuple of numpy + arrays. The vectorized function evaluates `pyfunc` over successive tuples of the input arrays like the python map function, except it uses the broadcasting rules of numpy. |