Sum of array elements over a given axis. Parameters ---------- a : array_like Elements to sum. axis : None or int or tuple of ints, optional Axis or axes along which a sum is performed. The default, axis=None, will sum all of the elements of the input a
(a, axis=None, dtype=None, out=None, keepdims=np._NoValue,
initial=np._NoValue, where=np._NoValue)
| 2341 | |
| 2342 | @array_function_dispatch(_sum_dispatcher) |
| 2343 | def sum(a, axis=None, dtype=None, out=None, keepdims=np._NoValue, |
| 2344 | initial=np._NoValue, where=np._NoValue): |
| 2345 | """ |
| 2346 | Sum of array elements over a given axis. |
| 2347 | |
| 2348 | Parameters |
| 2349 | ---------- |
| 2350 | a : array_like |
| 2351 | Elements to sum. |
| 2352 | axis : None or int or tuple of ints, optional |
| 2353 | Axis or axes along which a sum is performed. The default, |
| 2354 | axis=None, will sum all of the elements of the input array. If |
| 2355 | axis is negative it counts from the last to the first axis. If |
| 2356 | axis is a tuple of ints, a sum is performed on all of the axes |
| 2357 | specified in the tuple instead of a single axis or all the axes as |
| 2358 | before. |
| 2359 | dtype : dtype, optional |
| 2360 | The type of the returned array and of the accumulator in which the |
| 2361 | elements are summed. The dtype of `a` is used by default unless `a` |
| 2362 | has an integer dtype of less precision than the default platform |
| 2363 | integer. In that case, if `a` is signed then the platform integer |
| 2364 | is used while if `a` is unsigned then an unsigned integer of the |
| 2365 | same precision as the platform integer is used. |
| 2366 | out : ndarray, optional |
| 2367 | Alternative output array in which to place the result. It must have |
| 2368 | the same shape as the expected output, but the type of the output |
| 2369 | values will be cast if necessary. |
| 2370 | keepdims : bool, optional |
| 2371 | If this is set to True, the axes which are reduced are left |
| 2372 | in the result as dimensions with size one. With this option, |
| 2373 | the result will broadcast correctly against the input array. |
| 2374 | |
| 2375 | If the default value is passed, then `keepdims` will not be |
| 2376 | passed through to the `sum` method of sub-classes of |
| 2377 | `ndarray`, however any non-default value will be. If the |
| 2378 | sub-class' method does not implement `keepdims` any |
| 2379 | exceptions will be raised. |
| 2380 | initial : scalar, optional |
| 2381 | Starting value for the sum. See `~numpy.ufunc.reduce` for details. |
| 2382 | where : array_like of bool, optional |
| 2383 | Elements to include in the sum. See `~numpy.ufunc.reduce` for details. |
| 2384 | |
| 2385 | Returns |
| 2386 | ------- |
| 2387 | sum_along_axis : ndarray |
| 2388 | An array with the same shape as `a`, with the specified |
| 2389 | axis removed. If `a` is a 0-d array, or if `axis` is None, a scalar |
| 2390 | is returned. If an output array is specified, a reference to |
| 2391 | `out` is returned. |
| 2392 | |
| 2393 | See Also |
| 2394 | -------- |
| 2395 | ndarray.sum : Equivalent method. |
| 2396 | add: ``numpy.add.reduce`` equivalent function. |
| 2397 | cumsum : Cumulative sum of array elements. |
| 2398 | trapezoid : Integration of array values using composite trapezoidal rule. |
| 2399 | |
| 2400 | mean, average |