ndarray

The ndarray crate provides an N-dimensional container similar to numpy’s ndarray. Requires Rust 1.7.

Please read the API documentation here (master), (0.3), (0.2)

Highlights

• Generic N-dimensional array
• Owned arrays and views
  • ArrayBase: The N-dimensional array type itself.
  • OwnedArray: An array where the data is owned uniquely.
  • RcArray: An array where the data has shared ownership and is copy on write.
  • ArrayView, ArrayViewMut: Lightweight array views.
• Slicing, also with arbitrary step size, and negative indices to mean elements from the end of the axis.
• Iteration and most operations are efficient on arrays with contiguous innermost dimension.
• Array views can be used to slice and mutate any [T] data.

Status and Lookout

• Still iterating on and evolving the API
  • The crate is continuously developing, and breaking changes are expected during evolution from version to version. We adhere to semver, but alpha releases break at will.
  • We adopt the newest stable rust features we need. In place methods like iadd will be deprecated when Rust supports += and similar in Rust 1.8.
  • We try to introduce more static checking gradually.
• Performance status:
  • Arithmetic involving arrays of contiguous inner dimension optimizes very well.
  • .fold() and .zip_mut_with() are the most efficient ways to perform single traversal and lock step traversal respectively.
  • .iter() and .iter_mut() are efficient for contiguous arrays.
  • Can use BLAS in some operations (dot and mat_mul).

Crate Feature Flags

The following crate feature flags are available. The are configured in your Cargo.toml.

• assign_ops
  • Requires Rust 1.8, will be default soon.
  • Enables the compound assignment operators
• rustc-serialize
  • Optional, stable
  • Enables serialization support
• rblas
  • Deprecated: replaced by separate crate ndarray-rblas
  • Enables rblas integration

How to use with cargo:

[dependencies]
ndarray = "0.4"

Recent Changes

• 0.4.1
  • Mark iterators Send + Sync when possible.
• 0.4.0 Release Announcement
  • New array splitting via .split_at(Axis, Ix) and .axis_chunks_iter()
  • Added traits NdFloat, AsArray and From for ArrayView which improve generic programming.
  • Array constructors panic when attempting to create an array whose element count overflows usize. (Would be a debug assertion for overflow before.)
  • Performance improvements for .map().
  • Added stack and macro stack![axis, arrays..] to concatenate arrays.
  • Added constructor OwnedArray::range(start, end, step).
  • The type alias Array was renamed to RcArray (and the old name deprecated).
  • Binary operators are not defined when consuming a mutable array view as the left hand side argument anymore.
  • Remove methods and items deprecated since 0.3 or earlier; deprecated methods have notes about replacements in 0.3 docs.
  • See below for full changelog through alphas.

• 0.4.0-alpha.8
  • In debug mode, indexing an array out of bounds now has a detailed message about index and shape. (In release mode it does not.)
  • Enable assign_ops feature automatically when it is supported (Rust 1.8 beta or later).
  • Add trait NdFloat which makes it easy to be generic over f32, f64.
  • Add From implementations that convert slices or references to arrays into array views. This replaces from_slice from a previous alpha.
  • Add AsArray trait, which is simply based on those From implementations.
  • Improve .map() so that it can autovectorize.
  • Use Axis argument in RemoveAxis too.
  • Require DataOwned in the raw data methods.
  • Merged error types into a single ShapeError, which uses no allocated data.
• 0.4.0-alpha.7
  • Fix too strict lifetime bound in arithmetic operations like &a @ &b.
  • Rename trait Scalar to ScalarOperand (and improve its docs).
  • Implement <<= and >>= for arrays.
• 0.4.0-alpha.6
  • All axis arguments must now be wrapped in newtype Axis.
  • Add method .split_at(Axis, Ix) to read-only and read-write array views.
  • Add constructors ArrayView{,Mut}::from_slice and array view methods are now visible in the docs.
• 0.4.0-alpha.5
  • Use new trait LinalgScalar for operations where we want type-based specialization. This shrinks the set of types that allow dot product, matrix multiply, mean.
  • Use BLAS acceleration transparently in .dot() (this is the first step).
  • Only OwnedArray and RcArray and not ArrayViewMut can now be used as consumed left hand operand for arithmetic operators. See arithmetic operations docs!
  • Remove deprecated module linalg (it was already mostly empty)
  • Deprecate free function zeros in favour of static method zeros.

• 0.4.0-alpha.4
  • Rename Array to RcArray. Old name is deprecated.
  • Add methods OuterIter::split_at, OuterIterMut::split_at
  • Change arr0, arr1, arr2, arr3 to return OwnedArray. Add rcarr1, rcarr2, rcarr3 that return RcArray.
• 0.4.0-alpha.3
  • Improve arithmetic operations where the RHS is a broadcast 0-dimensional array.
  • Add read-only and read-write array views to the rblas integration. Added methods AsBlas::{blas_view_checked, blas_view_mut_checked, bv, bvm}.
  • Use hash_slice in Hash impl for arrays.
• 0.4.0-alpha.2
  • Add ArrayBase::reversed_axes which transposes an array.
• 0.4.0-alpha.1
  • Add checked and unchecked constructor methods for creating arrays from a vector and explicit dimension and stride, or with fortran (column major) memory order (marked f):
    • ArrayBase::from_vec_dim, from_vec_dim_stride, from_vec_dim_stride_unchecked,
    • from_vec_dim_unchecked_f, from_elem_f, zeros_f
    • View constructors ArrayView::from_slice_dim_stride, ArrayViewMut::from_slice_dim_stride.
    • Rename old ArrayBase::from_vec_dim to from_vec_dim_unchecked.
  • Check better for wraparound when computing the number of elements in a shape; this adds error cases that panic in from_elem, zeros etc, however the new check will only ever panic in cases that would trigger debug assertions for overflow in the previous versions!.
  • Add an array chunks iterator .axis_chunks_iter() and mutable version; it allows traversing the array in for example chunks of n rows at a time.
  • Remove methods and items deprecated since 0.3 or earlier; deprecated methods have notes about replacements in 0.3 docs.
• 0.3.1
  • Add .row_mut(), .column_mut()
  • Add .axis_iter(), .axis_iter_mut()
• 0.3.0
  • Second round of API & consistency update is done
  • 0.3.0 highlight: Index type Ix changed to usize.
  • 0.3.0 highlight: Operator overloading for scalar and array arithmetic.
  • 0.3.0 highlight: Indexing with a[[i, j, k]] syntax.
  • Add ArrayBase::eye(n)
  • See below for more info
• 0.3.0-alpha.4
  • Shrink array view structs by removing their redundant slice field (see #45). Changed the definition of the view type aliases.
  • .mat_mul() and .mat_mul_col() now return OwnedArray. Use .into_shared() if you need an Array.
  • impl ExactSizeIterator where possible for iterators.
  • impl DoubleEndedIterator for .outer_iter() (and _mut).
• 0.3.0-alpha.3
  • .subview() changed to return an array view, also added into_subview().
  • Add .outer_iter() and .outer_iter_mut() for iteration along the greatest axis of the array. Views also implement into_outer_iter() for “lifetime preserving” iterators.
• 0.3.0-alpha.2
  • Improve the strided last dimension case in zip_mut_with slightly (affects all binary operations).
  • Add .row(i), .column(i) for 2D arrays.
  • Deprecate .row_iter(), .col_iter().
  • Add method .dot() for computing the dot product between two 1D arrays.
• 0.3.0-alpha.1
  • Index type Ix changed to usize (#9). Gives better iterator codegen and 64-bit size arrays.
  • Support scalar operands with arithmetic operators.
  • Change .slice() and .diag() to return array views, add .into_diag().
  • Add ability to use fixed size arrays for array indexing, enabling syntax like a[[i, j]] for indexing.
  • Add .ndim()
• 0.2.0
  • First chapter of API and performance evolution is done \o/
  • 0.2.0 highlight: Vectorized (efficient) arithmetic operations
  • 0.2.0 highlight: Easier slicing using s![]
  • 0.2.0 highlight: Nicer API using views
  • 0.2.0 highlight: Bridging to BLAS functions.
  • See below for more info
• 0.2.0-alpha.9
  • Support strided matrices in rblas bridge, and fix a bug with non square matrices.
  • Deprecated all of module linalg.
• 0.2.0-alpha.8
  • Note: PACKAGE NAME CHANGED TO ndarray. Having package != crate ran into many quirks of various tools. Changing the package name is easier for everyone involved!
  • Optimized scalar_sum() so that it will vectorize for the floating point element case too.
• 0.2.0-alpha.7
  • Optimized arithmetic operations!
    • For c-contiguous arrays or arrays with c-contiguous lowest dimension they optimize very well, and can vectorize!
  • Add .inner_iter(), .inner_iter_mut()
  • Add .fold(), .zip_mut_with()
  • Add .scalar_sum()
  • Add example examples/life.rs
• 0.2.0-alpha.6
  • Add #[deprecated] attributes (enabled with new enough nightly)
  • Add ArrayBase::linspace, deprecate constructor range.
• 0.2.0-alpha.5
  • Add s![...], a slice argument macro.
  • Add aview_mut1(), zeros()
  • Add .diag_mut() and deprecate .diag_iter_mut(), .sub_iter_mut()
  • Add .uget(), .uget_mut() for unchecked indexing and deprecate the old names.
  • Improve ArrayBase::from_elem
  • Removed SliceRange, replaced by From impls for Si.
• 0.2.0-alpha.4
  • Slicing methods like .slice() now take a fixed size array of Si as the slice description. This allows more type checking to verify that the number of axes is correct.
  • Add experimental rblas integration.
  • Add into_shape() which allows reshaping any array or view kind.
• 0.2.0-alpha.3
  • Add and edit a lot of documentation
• 0.2.0-alpha.2
  • Improve performance for iterators when the array data is in the default memory layout. The iterator then wraps the default slice iterator and loops will autovectorize.
  • Remove method .indexed() on iterators. Changed Indexed and added ÌndexedMut.
  • Added .as_slice(), .as_mut_slice()
  • Support rustc-serialize
• 0.2.0-alpha
  • Alpha release!
  • Introduce ArrayBase, OwnedArray, ArrayView, ArrayViewMut
  • All arithmetic operations should accept any array type
  • Array continues to refer to the default reference counted copy on write array
  • Add .view(), .view_mut(), .to_owned(), .into_shared()
  • Add .slice_mut(), .subview_mut()
  • Some operations now return OwnedArray:
    • .map()
    • .sum()
    • .mean()
  • Add get, get_mut to replace the now deprecated at, at_mut.
  • Fix bug in assign_scalar
• 0.1.1
  • Add Array::default
  • Fix bug in raw_data_mut
• 0.1.0
  • First release on crates.io
  • Starting point for evolution to come

License

Dual-licensed to be compatible with the Rust project.

Licensed under the Apache License, Version 2.0 http://www.apache.org/licenses/LICENSE-2.0 or the MIT license http://opensource.org/licenses/MIT, at your option. This file may not be copied, modified, or distributed except according to those terms.