### Navigation

- index
- modules |
- next |
- previous |
- NumPy v1.3 Manual (DRAFT) »
- NumPy Reference »
- Routines »

# Indexing routines

See also

Indexing

## Generating index arrays

`c_` | Translates slice objects to concatenation along the second axis.
`r_` | Translates slice objects to concatenation along the first axis.
`s_` | A nicer way to build up index tuples for arrays.
`nonzero` (a) | Return the indices of the elements that are non-zero.
`where` (condition, [x, y]) | Return elements, either from x or y, depending on condition.
`indices` (dimensions[, dtype]) | Return an array representing the indices of a grid.
`ix_` (*args) | Construct an open mesh from multiple sequences.
`ogrid` | Construct a multi-dimensional open “meshgrid”.
`unravel_index` (x, dims) | Convert a flat index into an index tuple for an array of given shape.

## Indexing-like operations

`take` (a, indices[, axis, out, mode]) | Take elements from an array along an axis.
`choose` (a, choices[, out, mode]) | Use an index array to construct a new array from a set of choices.
`compress` (condition, a[, axis, out]) | Return selected slices of an array along given axis.
`diag` (v[, k]) | Extract a diagonal or construct a diagonal array.
`diagonal` (a[, offset, axis1, axis2]) | Return specified diagonals.
`select` (condlist, choicelist[, default]) | Return an array drawn from elements in choicelist, depending on conditions.

## Inserting data into arrays

`place` (arr, mask, vals) | Changes elements of an array based on conditional and input values.
`put` (a, ind, v[, mode]) | Changes specific elements of one array by replacing from another array.
`putmask` (a, mask, values) | Changes elements of an array based on conditional and input values.

## Iterating over arrays

`ndenumerate` | Multidimensional index iterator.
`ndindex` | Pass in a sequence of integers corresponding to the number of dimensions in the counter. This iterator will then return an N-dimensional counter.
`flatiter` |

### Navigation

- index
- modules |
- next |
- previous |
- NumPy v1.3 Manual (DRAFT) »
- NumPy Reference »
- Routines »