diff --git a/src/impl_methods.rs b/src/impl_methods.rs index f21b407e1..eea017161 100644 --- a/src/impl_methods.rs +++ b/src/impl_methods.rs @@ -2017,8 +2017,6 @@ where /// possible, otherwise they are copied to create a new array. /// /// If an index ordering is not specified, the default is `RowMajor`. - /// The operation will only succeed if the array's memory layout is compatible with - /// the index ordering, so that the array elements can be rearranged in place. /// /// # `.to_shape` vs `.into_shape_clone` /// @@ -2131,6 +2129,69 @@ where } } + /// Flatten the array to a one-dimensional array. + /// + /// The array is returned as a `CowArray`; a view if possible, otherwise an owned array. + /// + /// ``` + /// use ndarray::{arr1, arr3}; + /// + /// let array = arr3(&[[[1, 2], [3, 4]], [[5, 6], [7, 8]]]); + /// let flattened = array.flatten(); + /// assert_eq!(flattened, arr1(&[1, 2, 3, 4, 5, 6, 7, 8])); + /// ``` + pub fn flatten(&self) -> CowArray<'_, A, Ix1> + where + A: Clone, + S: Data, + { + self.flatten_with_order(Order::RowMajor) + } + + /// Flatten the array to a one-dimensional array. + /// + /// `order` specifies the *logical* order in which the array is to be read and reshaped. + /// The array is returned as a `CowArray`; a view if possible, otherwise an owned array. + /// + /// ``` + /// use ndarray::{arr1, arr2}; + /// use ndarray::Order; + /// + /// let array = arr2(&[[1, 2], [3, 4], [5, 6], [7, 8]]); + /// let flattened = array.flatten_with_order(Order::RowMajor); + /// assert_eq!(flattened, arr1(&[1, 2, 3, 4, 5, 6, 7, 8])); + /// let flattened = array.flatten_with_order(Order::ColumnMajor); + /// assert_eq!(flattened, arr1(&[1, 3, 5, 7, 2, 4, 6, 8])); + /// ``` + pub fn flatten_with_order(&self, order: Order) -> CowArray<'_, A, Ix1> + where + A: Clone, + S: Data, + { + self.to_shape((self.len(), order)).unwrap() + } + + /// Flatten the array to a one-dimensional array, consuming the array. + /// + /// If possible, no copy is made, and the new array use the same memory as the original array. + /// Otherwise, a new array is allocated and the elements are copied. + /// + /// ``` + /// use ndarray::{arr1, arr3}; + /// + /// let array = arr3(&[[[1, 2], [3, 4]], [[5, 6], [7, 8]]]); + /// let flattened = array.into_flat(); + /// assert_eq!(flattened, arr1(&[1, 2, 3, 4, 5, 6, 7, 8])); + /// ``` + pub fn into_flat(self) -> ArrayBase + where + A: Clone, + S: DataOwned, + { + let len = self.len(); + self.into_shape_clone(Ix1(len)).unwrap() + } + /// Convert any array or array view to a dynamic dimensional array or /// array view (respectively). /// @@ -3065,3 +3126,32 @@ unsafe fn unlimited_transmute(data: A) -> B } type DimMaxOf = >::Output; + +#[cfg(test)] +mod tests { + use super::*; + use crate::arr3; + + #[test] + fn test_flatten() { + let array = arr3(&[[[1, 2], [3, 4]], [[5, 6], [7, 8]]]); + let flattened = array.flatten(); + assert_eq!(flattened, arr1(&[1, 2, 3, 4, 5, 6, 7, 8])); + } + + #[test] + fn test_flatten_with_order() { + let array = arr2(&[[1, 2], [3, 4], [5, 6], [7, 8]]); + let flattened = array.flatten_with_order(Order::RowMajor); + assert_eq!(flattened, arr1(&[1, 2, 3, 4, 5, 6, 7, 8])); + let flattened = array.flatten_with_order(Order::ColumnMajor); + assert_eq!(flattened, arr1(&[1, 3, 5, 7, 2, 4, 6, 8])); + } + + #[test] + fn test_into_flat() { + let array = arr3(&[[[1, 2], [3, 4]], [[5, 6], [7, 8]]]); + let flattened = array.into_flat(); + assert_eq!(flattened, arr1(&[1, 2, 3, 4, 5, 6, 7, 8])); + } +}