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Diffstat (limited to 'doc/source/reference/c-api.iterator.rst')
| -rw-r--r-- | doc/source/reference/c-api.iterator.rst | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/doc/source/reference/c-api.iterator.rst b/doc/source/reference/c-api.iterator.rst index b26845434..084fdcbce 100644 --- a/doc/source/reference/c-api.iterator.rst +++ b/doc/source/reference/c-api.iterator.rst @@ -229,7 +229,7 @@ is used to control the memory layout of the allocated result, typically npy_intp i; do { npy_intp size = *innersizeptr; - char *src = dataaddr[0], *dst = dataaddr[1]; + char *src = dataptrarray[0], *dst = dataptrarray[1]; for(i = 0; i < size; i++, src += innerstride, dst += itemsize) { memcpy(dst, src, itemsize); } @@ -369,7 +369,14 @@ Construction and Destruction Causes the iterator to track a multi-index. This prevents the iterator from coalescing axes to - produce bigger inner loops. + produce bigger inner loops. If the loop is also not buffered + and no index is being tracked (`NpyIter_RemoveAxis` can be called), + then the iterator size can be ``-1`` to indicate that the iterator + is too large. This can happen due to complex broadcasting and + will result in errors being created when the setting the iterator + range, removing the multi index, or getting the next function. + However, it is possible to remove axes again and use the iterator + normally if the size is small enough after removal. .. cvar:: NPY_ITER_EXTERNAL_LOOP @@ -412,8 +419,9 @@ Construction and Destruction Indicates that arrays with a size of zero should be permitted. Since the typical iteration loop does not naturally work with - zero-sized arrays, you must check that the IterSize is non-zero - before entering the iteration loop. + zero-sized arrays, you must check that the IterSize is larger + than zero before entering the iteration loop. + Currently only the operands are checked, not a forced shape. .. cvar:: NPY_ITER_REDUCE_OK @@ -721,7 +729,7 @@ Construction and Destruction **WARNING**: This function may change the internal memory layout of the iterator. Any cached functions or pointers from the iterator - must be retrieved again! + must be retrieved again! The iterator range will be reset as well. Returns ``NPY_SUCCEED`` or ``NPY_FAIL``. @@ -887,7 +895,11 @@ Construction and Destruction .. cfunction:: npy_intp NpyIter_GetIterSize(NpyIter* iter) Returns the number of elements being iterated. This is the product - of all the dimensions in the shape. + of all the dimensions in the shape. When a multi index is being tracked + (and `NpyIter_RemoveAxis` may be called) the size may be ``-1`` to + indicate an iterator is too large. Such an iterator is invalid, but + may become valid after `NpyIter_RemoveAxis` is called. It is not + necessary to check for this case. .. cfunction:: npy_intp NpyIter_GetIterIndex(NpyIter* iter) |