Implement hstack and vstack.

The implementation uses a trait to fold over tuples, summing the
dimensions in one direction and checking for equality in the other, and
then uses `fixed_{rows,columns}_mut` if the dimensions are static, or
`{rows,columns}_mut` if the dimensions are dynamic, together with
`copy_from` to construct the output matrix.
This commit is contained in:
Avi Weinstock 2023-01-30 23:14:20 -05:00
parent 52e6db99c6
commit 317aef574a
3 changed files with 349 additions and 0 deletions

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@ -305,3 +305,46 @@ fn dvector_arbitrary_expressions() {
let a_expected = DVector::from_column_slice(&[1 + 2, 2 * 3, 4 * f(5 + 6), 7 - 8 * 9]);
assert_eq_and_type!(a, a_expected);
}
#[test]
fn test_stacking() {
use nalgebra::{hstack, vstack, RowVector3, RowVector4};
assert_eq_and_type!(
vstack((&RowVector3::new(1, 2, 3), &RowVector3::new(4, 5, 6))),
Matrix2x3::new(1, 2, 3, 4, 5, 6)
);
assert_eq_and_type!(
vstack((
&RowVector3::new(1, 2, 3),
&RowVector3::new(4, 5, 6),
&RowVector3::new(7, 8, 9)
)),
Matrix3::new(1, 2, 3, 4, 5, 6, 7, 8, 9)
);
assert_eq_and_type!(
hstack((&Vector3::new(1, 2, 3), &Vector3::new(4, 5, 6))),
Matrix3x2::new(1, 4, 2, 5, 3, 6)
);
assert_eq_and_type!(
hstack((
&Vector3::new(1, 2, 3),
&Vector3::new(4, 5, 6),
&Vector3::new(7, 8, 9)
)),
Matrix3::new(1, 4, 7, 2, 5, 8, 3, 6, 9)
);
assert_eq_and_type!(
vstack((
&hstack((&DMatrix::identity(3, 3), &Vector3::new(2, 2, 2))),
&RowVector4::new(3, 3, 3, 3)
)),
matrix![1, 0, 0, 2; 0, 1, 0, 2; 0, 0, 1, 2; 3, 3, 3, 3]
);
assert_eq_and_type!(
vstack((
&hstack((&DMatrix::identity(3, 3), &dvector![2, 2, 2],)),
&dvector![3, 3, 3, 3].transpose(),
)),
dmatrix![1, 0, 0, 2; 0, 1, 0, 2; 0, 0, 1, 2; 3, 3, 3, 3]
);
}

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@ -8,6 +8,7 @@ pub mod default_allocator;
pub mod dimension;
pub mod iter;
mod ops;
mod stacking;
pub mod storage;
mod alias;
@ -61,6 +62,7 @@ pub use self::alias_slice::*;
pub use self::alias_view::*;
pub use self::array_storage::*;
pub use self::matrix_view::*;
pub use self::stacking::{hstack, vstack};
pub use self::storage::*;
#[cfg(any(feature = "std", feature = "alloc"))]
pub use self::vec_storage::*;

304
src/base/stacking.rs Normal file
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@ -0,0 +1,304 @@
///! Utilities for stacking matrices horizontally and vertically.
use crate::{
base::allocator::Allocator,
constraint::{DimEq, SameNumberOfColumns, SameNumberOfRows, ShapeConstraint},
Const, DefaultAllocator, Dim, DimAdd, DimSum, Dyn, Matrix, RawStorage, RawStorageMut, Scalar,
};
use num_traits::Zero;
/// A visitor for each folding over each element of a tuple.
pub trait Visitor<A> {
/// The output type of this step.
type Output;
/// Visits an element of a tuple.
fn visit(self, x: A) -> Self::Output;
}
/// The driver for visiting each element of a tuple.
pub trait VisitTuple<F> {
/// The output type of the fold.
type Output;
/// Visits each element of a tuple.
fn visit(visitor: F, x: Self) -> Self::Output;
}
macro_rules! impl_visit_tuple {
($($is:ident),*) => {
impl_visit_tuple!(__GENERATE_TAILS, [$($is),*]);
};
(__GENERATE_TAILS, [$i:ident]) => {
impl_visit_tuple!(__GENERATE_CLAUSE, [$i]);
};
(__GENERATE_TAILS, [$i:ident, $($is:ident),*]) => {
impl_visit_tuple!(__GENERATE_CLAUSE, [$i, $($is),*]);
impl_visit_tuple!(__GENERATE_TAILS, [$($is),*]);
};
(__GENERATE_CLAUSE, [$i:ident]) => {
impl<$i, Func: Visitor<$i>> VisitTuple<Func> for ($i,) {
type Output = <Func as Visitor<$i>>::Output;
#[allow(non_snake_case)]
fn visit(visitor: Func, ($i,): Self) -> Self::Output {
visitor.visit($i)
}
}
};
(__GENERATE_CLAUSE, [$i:ident, $($is:ident),*]) => {
impl<$i, $($is,)* Func: Visitor<$i>> VisitTuple<Func> for ($i, $($is),*)
where ($($is,)*): VisitTuple<<Func as Visitor<$i>>::Output>
{
type Output = <($($is,)*) as VisitTuple<<Func as Visitor<$i>>::Output>>::Output;
#[allow(non_snake_case)]
fn visit(visitor: Func, ($i, $($is),*): Self) -> Self::Output {
VisitTuple::visit(visitor.visit($i), ($($is,)*))
}
}
};
}
impl_visit_tuple!(H, G, F, E, D, C, B, A);
mod vstack_impl {
use super::*;
#[derive(Clone, Copy)]
pub struct VStackShapeInit;
#[derive(Clone, Copy)]
pub struct VStackShape<R, C> {
r: R,
c: C,
}
impl<T: Scalar, R: Dim, C: Dim, S: RawStorage<T, R, C>> Visitor<&Matrix<T, R, C, S>>
for VStackShapeInit
{
type Output = VStackShape<R, C>;
fn visit(self, x: &Matrix<T, R, C, S>) -> Self::Output {
let (r, c) = x.shape_generic();
VStackShape { r, c }
}
}
impl<T: Scalar, R1: Dim + DimAdd<R2>, C1: Dim, R2: Dim, C2: Dim, S2: RawStorage<T, R2, C2>>
Visitor<&Matrix<T, R2, C2, S2>> for VStackShape<R1, C1>
where
ShapeConstraint: SameNumberOfColumns<C1, C2>,
{
type Output =
VStackShape<DimSum<R1, R2>, <ShapeConstraint as DimEq<C1, C2>>::Representative>;
fn visit(self, x: &Matrix<T, R2, C2, S2>) -> Self::Output {
let (r, c) = x.shape_generic();
VStackShape {
r: self.r.add(r),
c: <ShapeConstraint as DimEq<C1, C2>>::Representative::from_usize(c.value()),
}
}
}
pub struct VStack<T, R, C, S, R2> {
out: Matrix<T, R, C, S>,
current_row: R2,
}
impl<
T: Scalar,
R1: Dim + DimAdd<Const<R2>>,
C1: Dim,
S1: RawStorageMut<T, R1, C1>,
const R2: usize,
C2: Dim,
S2: RawStorage<T, Const<R2>, C2>,
R3: Dim + DimAdd<Const<R2>>,
> Visitor<&Matrix<T, Const<R2>, C2, S2>> for VStack<T, R1, C1, S1, R3>
where
ShapeConstraint: SameNumberOfColumns<C1, C2>,
{
type Output = VStack<T, R1, C1, S1, DimSum<R3, Const<R2>>>;
fn visit(self, x: &Matrix<T, Const<R2>, C2, S2>) -> Self::Output {
let (r2, _) = x.shape_generic();
let VStack {
mut out,
current_row,
} = self;
out.fixed_rows_mut::<{ R2 }>(current_row.value())
.copy_from::<Const<R2>, C2, S2>(x);
let current_row = current_row.add(r2);
VStack { out, current_row }
}
}
impl<
T: Scalar,
R1: Dim + DimAdd<Dyn>,
C1: Dim,
S1: RawStorageMut<T, R1, C1>,
C2: Dim,
S2: RawStorage<T, Dyn, C2>,
R3: Dim + DimAdd<Dyn>,
> Visitor<&Matrix<T, Dyn, C2, S2>> for VStack<T, R1, C1, S1, R3>
where
ShapeConstraint: SameNumberOfColumns<C1, C2>,
{
type Output = VStack<T, R1, C1, S1, DimSum<R3, Dyn>>;
fn visit(self, x: &Matrix<T, Dyn, C2, S2>) -> Self::Output {
let (r2, _) = x.shape_generic();
let VStack {
mut out,
current_row,
} = self;
out.rows_mut(current_row.value(), r2.value())
.copy_from::<Dyn, C2, S2>(x);
let current_row = current_row.add(r2);
VStack { out, current_row }
}
}
/// Stack a tuple of references to matrices with equal column counts vertically, yielding a
/// matrix with every row of the input matrices.
pub fn vstack<
T: Scalar + Zero,
R: Dim,
C: Dim,
X: Copy
+ VisitTuple<VStackShapeInit, Output = VStackShape<R, C>>
+ VisitTuple<
VStack<T, R, C, <DefaultAllocator as Allocator<T, R, C>>::Buffer, Const<0>>,
Output = VStack<T, R, C, <DefaultAllocator as Allocator<T, R, C>>::Buffer, R>,
>,
>(
x: X,
) -> Matrix<T, R, C, <DefaultAllocator as Allocator<T, R, C>>::Buffer>
where
DefaultAllocator: Allocator<T, R, C>,
{
let vstack_shape = VStackShapeInit;
let vstack_shape = <X as VisitTuple<_>>::visit(vstack_shape, x);
let vstack_visitor = VStack {
out: Matrix::zeros_generic(vstack_shape.r, vstack_shape.c),
current_row: Const,
};
let vstack_visitor = <X as VisitTuple<_>>::visit(vstack_visitor, x);
vstack_visitor.out
}
}
pub use vstack_impl::vstack;
mod hstack_impl {
use super::*;
#[derive(Clone, Copy)]
pub struct HStackShapeInit;
#[derive(Clone, Copy)]
pub struct HStackShape<R, C> {
r: R,
c: C,
}
impl<T: Scalar, R: Dim, C: Dim, S: RawStorage<T, R, C>> Visitor<&Matrix<T, R, C, S>>
for HStackShapeInit
{
type Output = HStackShape<R, C>;
fn visit(self, x: &Matrix<T, R, C, S>) -> Self::Output {
let (r, c) = x.shape_generic();
HStackShape { r, c }
}
}
impl<T: Scalar, R1: Dim, C1: Dim + DimAdd<C2>, R2: Dim, C2: Dim, S2: RawStorage<T, R2, C2>>
Visitor<&Matrix<T, R2, C2, S2>> for HStackShape<R1, C1>
where
ShapeConstraint: SameNumberOfRows<R1, R2>,
{
type Output =
HStackShape<<ShapeConstraint as DimEq<R1, R2>>::Representative, DimSum<C1, C2>>;
fn visit(self, x: &Matrix<T, R2, C2, S2>) -> Self::Output {
let (r, c) = x.shape_generic();
HStackShape {
r: <ShapeConstraint as DimEq<R1, R2>>::Representative::from_usize(r.value()),
c: self.c.add(c),
}
}
}
pub struct HStack<T, R, C, S, C2> {
out: Matrix<T, R, C, S>,
current_col: C2,
}
impl<
T: Scalar,
R1: Dim,
C1: Dim + DimAdd<Const<C2>>,
S1: RawStorageMut<T, R1, C1>,
R2: Dim,
const C2: usize,
S2: RawStorage<T, R2, Const<C2>>,
C3: Dim + DimAdd<Const<C2>>,
> Visitor<&Matrix<T, R2, Const<C2>, S2>> for HStack<T, R1, C1, S1, C3>
where
ShapeConstraint: SameNumberOfRows<R1, R2>,
{
type Output = HStack<T, R1, C1, S1, DimSum<C3, Const<C2>>>;
fn visit(self, x: &Matrix<T, R2, Const<C2>, S2>) -> Self::Output {
let (_, c2) = x.shape_generic();
let HStack {
mut out,
current_col,
} = self;
out.fixed_columns_mut::<{ C2 }>(current_col.value())
.copy_from::<R2, Const<C2>, S2>(x);
let current_col = current_col.add(c2);
HStack { out, current_col }
}
}
impl<
T: Scalar,
R1: Dim,
C1: Dim + DimAdd<Dyn>,
S1: RawStorageMut<T, R1, C1>,
R2: Dim,
S2: RawStorage<T, R2, Dyn>,
C3: Dim + DimAdd<Dyn>,
> Visitor<&Matrix<T, R2, Dyn, S2>> for HStack<T, R1, C1, S1, C3>
where
ShapeConstraint: SameNumberOfRows<R1, R2>,
{
type Output = HStack<T, R1, C1, S1, DimSum<C3, Dyn>>;
fn visit(self, x: &Matrix<T, R2, Dyn, S2>) -> Self::Output {
let (_, c2) = x.shape_generic();
let HStack {
mut out,
current_col,
} = self;
out.columns_mut(current_col.value(), c2.value())
.copy_from::<R2, Dyn, S2>(x);
let current_col = current_col.add(c2);
HStack { out, current_col }
}
}
/// Stack a tuple of references to matrices with equal row counts horizontally, yielding a
/// matrix with every column of the input matrices.
pub fn hstack<
T: Scalar + Zero,
R: Dim,
C: Dim,
X: Copy
+ VisitTuple<HStackShapeInit, Output = HStackShape<R, C>>
+ VisitTuple<
HStack<T, R, C, <DefaultAllocator as Allocator<T, R, C>>::Buffer, Const<0>>,
Output = HStack<T, R, C, <DefaultAllocator as Allocator<T, R, C>>::Buffer, C>,
>,
>(
x: X,
) -> Matrix<T, R, C, <DefaultAllocator as Allocator<T, R, C>>::Buffer>
where
DefaultAllocator: Allocator<T, R, C>,
{
let hstack_shape = HStackShapeInit;
let hstack_shape = <X as VisitTuple<_>>::visit(hstack_shape, x);
let hstack_visitor = HStack {
out: Matrix::zeros_generic(hstack_shape.r, hstack_shape.c),
current_col: Const,
};
let hstack_visitor = <X as VisitTuple<_>>::visit(hstack_visitor, x);
hstack_visitor.out
}
}
pub use hstack_impl::hstack;