pub fn take(
values: &dyn Array,
indices: &dyn Array,
options: Option<TakeOptions>,
) -> Result<ArrayRef, ArrowError>
Expand description
Take elements by index from Array, creating a new Array from those indexes.
┌─────────────────┐ ┌─────────┐ ┌─────────────────┐
│ A │ │ 0 │ │ A │
├─────────────────┤ ├─────────┤ ├─────────────────┤
│ D │ │ 2 │ │ B │
├─────────────────┤ ├─────────┤ take(values, indices) ├─────────────────┤
│ B │ │ 3 │ ─────────────────────────▶ │ C │
├─────────────────┤ ├─────────┤ ├─────────────────┤
│ C │ │ 1 │ │ D │
├─────────────────┤ └─────────┘ └─────────────────┘
│ E │
└─────────────────┘
values array indices array result
For selecting values by index from multiple arrays see crate::interleave
Note that this kernel, similar to other kernels in this crate, will avoid allocating where not necessary. Consequently the returned array may share buffers with the inputs
§Errors
This function errors whenever:
- An index cannot be casted to
usize
(typically 32 bit architectures) - An index is out of bounds and
options
is set to check bounds.
§Safety
When options
is not set to check bounds, taking indexes after len
will panic.
§Examples
let values = StringArray::from(vec!["zero", "one", "two"]);
// Take items at index 2, and 1:
let indices = UInt32Array::from(vec![2, 1]);
let taken = take(&values, &indices, None).unwrap();
let taken = taken.as_string::<i32>();
assert_eq!(*taken, StringArray::from(vec!["two", "one"]));