nalgebra/src/structs/dvec_macros.rs

#![macro_escape]

macro_rules! dvec_impl(
    ($dvec: ident) => (
        impl<N: Zero + Clone> $dvec<N> {
            /// Builds a vector filled with zeros.
            ///
            /// # Arguments
            /// * `dim` - The dimension of the vector.
            #[inline]
            pub fn new_zeros(dim: uint) -> $dvec<N> {
                $dvec::from_elem(dim, ::zero())
            }

            /// Tests if all components of the vector are zeroes.
            #[inline]
            pub fn is_zero(&self) -> bool {
                self.as_slice().iter().all(|e| e.is_zero())
            }
        }

        impl<N> $dvec<N> {
            /// Slices this vector.
            #[inline]
            pub fn as_slice<'a>(&'a self) -> &'a [N] {
                self.at.slice_to(self.len())
            }

            /// Mutably slices this vector.
            #[inline]
            pub fn as_mut_slice<'a>(&'a mut self) -> &'a mut [N] {
                let len = self.len();
                self.at.slice_to_mut(len)
            }
        }

        impl<N> Shape<uint, N> for $dvec<N> {
            #[inline]
            fn shape(&self) -> uint {
                self.len()
            }
        }

        impl<N: Clone> Indexable<uint, N> for $dvec<N> {
            #[inline]
            fn at(&self, i: uint) -> N {
                assert!(i < self.len());
                unsafe {
                    self.unsafe_at(i)
                }
            }

            #[inline]
            fn set(&mut self, i: uint, val: N) {
                assert!(i < self.len());
                unsafe {
                    self.unsafe_set(i, val);
                }
            }

            #[inline]
            fn swap(&mut self, i: uint, j: uint) {
                assert!(i < self.len());
                assert!(j < self.len());
                self.as_mut_slice().swap(i, j);
            }

            #[inline]
            unsafe fn unsafe_at(&self, i: uint) -> N {
                (*self.at.as_slice().unsafe_get(i)).clone()
            }

            #[inline]
            unsafe fn unsafe_set(&mut self, i: uint, val: N) {
                *self.at.as_mut_slice().unsafe_mut(i) = val
            }

        }

        impl<N> Index<uint, N> for $dvec<N> {
            fn index(&self, i: &uint) -> &N {
                &self.as_slice()[*i]
            }
        }

        impl<N> IndexMut<uint, N> for $dvec<N> {
            fn index_mut(&mut self, i: &uint) -> &mut N {
                &mut self.as_mut_slice()[*i]
            }
        }

        impl<N: One + Zero + Clone> $dvec<N> {
            /// Builds a vector filled with ones.
            ///
            /// # Arguments
            /// * `dim` - The dimension of the vector.
            #[inline]
            pub fn new_ones(dim: uint) -> $dvec<N> {
                $dvec::from_elem(dim, ::one())
            }
        }

        impl<N: Rand + Zero> $dvec<N> {
            /// Builds a vector filled with random values.
            #[inline]
            pub fn new_random(dim: uint) -> $dvec<N> {
                $dvec::from_fn(dim, |_| rand::random())
            }
        }

        impl<N> Iterable<N> for $dvec<N> {
            #[inline]
            fn iter<'l>(&'l self) -> Items<'l, N> {
                self.as_slice().iter()
            }
        }

        impl<N> IterableMut<N> for $dvec<N> {
            #[inline]
            fn iter_mut<'l>(&'l mut self) -> MutItems<'l, N> {
                self.as_mut_slice().iter_mut()
            }
        }

        impl<N: Clone + BaseFloat + ApproxEq<N>> $dvec<N> {
            /// Computes the canonical basis for the given dimension. A canonical basis is a set of
            /// vectors, mutually orthogonal, with all its component equal to 0.0 except one which is equal
            /// to 1.0.
            pub fn canonical_basis_with_dim(dim: uint) -> Vec<$dvec<N>> {
                let mut res : Vec<$dvec<N>> = Vec::new();

                for i in range(0u, dim) {
                    let mut basis_element : $dvec<N> = $dvec::new_zeros(dim);

                    basis_element.set(i, ::one());

                    res.push(basis_element);
                }

                res
            }

            /// Computes a basis of the space orthogonal to the vector. If the input vector is of dimension
            /// `n`, this will return `n - 1` vectors.
            pub fn orthogonal_subspace_basis(&self) -> Vec<$dvec<N>> {
                // compute the basis of the orthogonal subspace using Gram-Schmidt
                // orthogonalization algorithm
                let     dim                 = self.len();
                let mut res : Vec<$dvec<N>> = Vec::new();

                for i in range(0u, dim) {
                    let mut basis_element : $dvec<N> = $dvec::new_zeros(self.len());

                    basis_element.set(i, ::one());

                    if res.len() == dim - 1 {
                        break;
                    }

                    let mut elt = basis_element.clone();

                    elt = elt - *self * Dot::dot(&basis_element, self);

                    for v in res.iter() {
                        elt = elt - *v * Dot::dot(&elt, v)
                    };

                    if !ApproxEq::approx_eq(&Norm::sqnorm(&elt), &::zero()) {
                        res.push(Norm::normalize_cpy(&elt));
                    }
                }

                assert!(res.len() == dim - 1);

                res
            }
        }

        impl<N: Mul<N, N> + Zero> Mul<$dvec<N>, $dvec<N>> for $dvec<N> {
            #[inline]
            fn mul(&self, right: &$dvec<N>) -> $dvec<N> {
                assert!(self.len() == right.len());
                FromIterator::from_iter(self.as_slice().iter().zip(right.as_slice().iter()).map(|(a, b)| *a * *b))
            }
        }

        impl<N: Div<N, N> + Zero> Div<$dvec<N>, $dvec<N>> for $dvec<N> {
            #[inline]
            fn div(&self, right: &$dvec<N>) -> $dvec<N> {
                assert!(self.len() == right.len());
                FromIterator::from_iter(self.as_slice().iter().zip(right.as_slice().iter()).map(|(a, b)| *a / *b))
            }
        }

        impl<N: Add<N, N> + Zero> Add<$dvec<N>, $dvec<N>> for $dvec<N> {
            #[inline]
            fn add(&self, right: &$dvec<N>) -> $dvec<N> {
                assert!(self.len() == right.len());
                FromIterator::from_iter(self.as_slice().iter().zip(right.as_slice().iter()).map(|(a, b)| *a + *b))
            }
        }

        impl<N: Sub<N, N> + Zero> Sub<$dvec<N>, $dvec<N>> for $dvec<N> {
            #[inline]
            fn sub(&self, right: &$dvec<N>) -> $dvec<N> {
                assert!(self.len() == right.len());
                FromIterator::from_iter(self.as_slice().iter().zip(right.as_slice().iter()).map(|(a, b)| *a - *b))
            }
        }

        impl<N: Neg<N> + Zero> Neg<$dvec<N>> for $dvec<N> {
            #[inline]
            fn neg(&self) -> $dvec<N> {
                FromIterator::from_iter(self.as_slice().iter().map(|a| -*a))
            }
        }

        impl<N: BaseNum + Clone> Dot<N> for $dvec<N> {
            #[inline]
            fn dot(&self, other: &$dvec<N>) -> N {
                assert!(self.len() == other.len());
                let mut res: N = ::zero();
                for i in range(0u, self.len()) {
                    res = res + unsafe { self.unsafe_at(i) * other.unsafe_at(i) };
                }
                res
            }
        }

        impl<N: BaseFloat + Clone> Norm<N> for $dvec<N> {
            #[inline]
            fn sqnorm(&self) -> N {
                Dot::dot(self, self)
            }

            #[inline]
            fn normalize_cpy(&self) -> $dvec<N> {
                let mut res : $dvec<N> = self.clone();
                let _ = res.normalize();
                res
            }

            #[inline]
            fn normalize(&mut self) -> N {
                let l = Norm::norm(self);

                for n in self.as_mut_slice().iter_mut() {
                    *n = *n / l;
                }

                l
            }
        }

        impl<N: ApproxEq<N>> ApproxEq<N> for $dvec<N> {
            #[inline]
            fn approx_epsilon(_: Option<$dvec<N>>) -> N {
                ApproxEq::approx_epsilon(None::<N>)
            }

            #[inline]
            fn approx_eq_eps(&self, other: &$dvec<N>, epsilon: &N) -> bool {
                let zip = self.as_slice().iter().zip(other.as_slice().iter());
                zip.all(|(a, b)| ApproxEq::approx_eq_eps(a, b, epsilon))
            }
        }

        impl<N: Mul<N, N> + Zero> Mul<N, $dvec<N>> for $dvec<N> {
            #[inline]
            fn mul(&self, right: &N) -> $dvec<N> {
                FromIterator::from_iter(self.as_slice().iter().map(|a| *a * *right))
            }
        }

        impl<N: Div<N, N> + Zero> Div<N, $dvec<N>> for $dvec<N> {
            #[inline]
            fn div(&self, right: &N) -> $dvec<N> {
                FromIterator::from_iter(self.as_slice().iter().map(|a| *a / *right))
            }
        }

        impl<N: Add<N, N> + Zero> Add<N, $dvec<N>> for $dvec<N> {
            #[inline]
            fn add(&self, right: &N) -> $dvec<N> {
                FromIterator::from_iter(self.as_slice().iter().map(|a| *a + *right))
            }
        }

        impl<N: Sub<N, N> + Zero> Sub<N, $dvec<N>> for $dvec<N> {
            #[inline]
            fn sub(&self, right: &N) -> $dvec<N> {
                FromIterator::from_iter(self.as_slice().iter().map(|a| *a - *right))
            }
        }
    )
)

macro_rules! small_dvec_impl (
    ($dvec: ident, $dim: expr $(,$idx: expr)*) => (
        impl<N> $dvec<N> {
            #[inline]
            pub fn len(&self) -> uint {
                self.dim
            }
        }

        impl<N: PartialEq> PartialEq for $dvec<N> {
            #[inline]
            fn eq(&self, other: &$dvec<N>) -> bool {
                if self.len() != other.len() {
                    return false; // FIXME: fail instead?
                }

                for (a, b) in self.as_slice().iter().zip(other.as_slice().iter()) {
                    if *a != *b {
                        return false;
                    }
                }

                true
            }
        }

        impl<N: Clone> Clone for $dvec<N> {
            fn clone(&self) -> $dvec<N> {
                let at: [N, ..$dim] = [ $( self.at[$idx].clone(), )* ];

                $dvec {
                    at:  at,
                    dim: self.dim
                }
            }
        }

        dvec_impl!($dvec)
    )
)

macro_rules! small_dvec_from_impl (
    ($dvec: ident, $dim: expr $(,$zeros: expr)*) => (
        impl<N: Clone + Zero> $dvec<N> {
            /// Builds a vector filled with a constant.
            #[inline]
            pub fn from_elem(dim: uint, elem: N) -> $dvec<N> {
                assert!(dim <= $dim);

                let mut at: [N, ..$dim] = [ $( $zeros, )* ];

                for n in at.slice_to_mut(dim).iter_mut() {
                    *n = elem.clone();
                }

                $dvec {
                    at:  at,
                    dim: dim
                }
            }
        }

        impl<N: Clone + Zero> $dvec<N> {
            /// Builds a vector filled with the components provided by a vector.
            ///
            /// The vector must have at least `dim` elements.
            #[inline]
            pub fn from_slice(dim: uint, vec: &[N]) -> $dvec<N> {
                assert!(dim <= vec.len() && dim <= $dim);

                // FIXME: not safe.
                let mut at: [N, ..$dim] = [ $( $zeros, )* ];

                for (curr, other) in vec.iter().zip(at.iter_mut()) {
                    *other = curr.clone();
                }

                $dvec {
                    at:  at,
                    dim: dim
                }
            }
        }

        impl<N: Zero> $dvec<N> {
            /// Builds a vector filled with the result of a function.
            #[inline(always)]
            pub fn from_fn(dim: uint, f: |uint| -> N) -> $dvec<N> {
                assert!(dim <= $dim);

                let mut at: [N, ..$dim] = [ $( $zeros, )* ];

                for i in range(0, dim) {
                    at[i] = f(i);
                }

                $dvec {
                    at:  at,
                    dim: dim
                }
            }
        }

        impl<N: Zero> FromIterator<N> for $dvec<N> {
            #[inline]
            fn from_iter<I: Iterator<N>>(mut param: I) -> $dvec<N> {
                let mut at: [N, ..$dim] = [ $( $zeros, )* ];

                let mut dim = 0;

                for n in param {
                    if dim == $dim {
                        break;
                    }

                    at[dim] = n;

                    dim = dim + 1;
                }

                $dvec {
                    at:  at,
                    dim: dim
                }
            }
        }
    )
)