Copies and views

Overview

A view is an ndarray that references the same underlying data as another array. A copy owns its own storage and is independent from the original. Views are fast and memory-efficient, but changes to the base array are visible through the view.

Creating views

Most indexing and slicing operations return views:

You can also create views explicitly with view and slice. Use base to check whether an array is a view:

Copies: copy and deepCopy

Use these methods to detach from a view and get independent data:

• copy() duplicates the underlying storage and preserves the current layout (offset/strides).

• deepCopy() materializes only the visible elements into a new contiguous array.

deepCopy() is usually the safer choice when you need a compact, standalone array or want to avoid copying data that is outside a view.

Views vs copies in common operations

Typical view-producing operations:

• Indexing and slicing

• view(...) and slice(...)

• transpose() and squeeze()

Operations that always allocate new storage:

• copy() and deepCopy()

• flatten()

• cat(...) and mk.stack(...)

Operations like reshape() and unsqueeze() return views when the array is contiguous; otherwise they materialize a copy to keep data consistent.