rlst 0.9.0

A Rust native linear algebra library.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237

use std::cell::Cell;

use crate::operator::{element::Element, interface::array_vector_space::ArrayVectorSpace};
use crate::{
    Array, ArrayFrameImpl, ElementFrame, FrameApply, FrameImpl, FrameQr, FrameQrDecomposition,
    FrameQrOptions, FrameRefAccess, GenericFrameImpl, LinearSpace, Norm, RlstResult, Shape,
    SliceArray, UnsafeRandom1DAccessByValue,
};

// Use a third implementation to ensure dispatch is truly generic. The counters
// distinguish backend overrides from defaults that would produce the same values.
struct ObservedFrameImpl<'a> {
    inner: GenericFrameImpl<'a, ArrayVectorSpace<f64>>,
    is_empty_calls: Cell<usize>,
    apply_calls: Cell<usize>,
    apply_into_calls: Cell<usize>,
    qr_calls: Cell<usize>,
    ref_calls: Cell<usize>,
    generation: usize,
}

impl<'a> ObservedFrameImpl<'a> {
    fn new(inner: GenericFrameImpl<'a, ArrayVectorSpace<f64>>, generation: usize) -> Self {
        Self {
            inner,
            is_empty_calls: Cell::new(0),
            apply_calls: Cell::new(0),
            apply_into_calls: Cell::new(0),
            qr_calls: Cell::new(0),
            ref_calls: Cell::new(0),
            generation,
        }
    }
}

impl<'a> FrameRefAccess<'a> for ObservedFrameImpl<'a> {
    fn element_ref(&self, index: usize) -> Option<&Element<'a, Self::Space>> {
        self.ref_calls.set(self.ref_calls.get() + 1);
        self.inner.element_ref(index)
    }
    fn element_mut<'s>(&'s mut self, index: usize) -> Option<&'s mut Element<'a, Self::Space>> {
        self.ref_calls.set(self.ref_calls.get() + 1);
        self.inner.element_mut(index)
    }
    fn iter<'s>(&'s self) -> impl ExactSizeIterator<Item = &'s Element<'a, Self::Space>>
    where
        'a: 's,
    {
        self.ref_calls.set(self.ref_calls.get() + 1);
        self.inner.iter()
    }
    fn iter_mut<'s>(&'s mut self) -> impl ExactSizeIterator<Item = &'s mut Element<'a, Self::Space>>
    where
        'a: 's,
    {
        self.ref_calls.set(self.ref_calls.get() + 1);
        self.inner.iter_mut()
    }
}

impl<'a> FrameImpl<'a> for ObservedFrameImpl<'a> {
    type Space = ArrayVectorSpace<f64>;

    fn space(&self) -> &'a Self::Space {
        self.inner.space()
    }
    fn element(&self, index: usize) -> Option<Element<'a, Self::Space>> {
        self.inner.element(index)
    }
    fn set_element(&mut self, index: usize, elem: &Element<Self::Space>) -> RlstResult<()> {
        self.inner.set_element(index, elem)
    }
    fn len(&self) -> usize {
        self.inner.len()
    }
    fn is_empty(&self) -> bool {
        self.is_empty_calls.set(self.is_empty_calls.get() + 1);
        self.inner.is_empty()
    }
    fn capacity(&self) -> usize {
        self.inner.capacity()
    }
    fn reserve(&mut self, additional: usize) {
        self.inner.reserve(additional);
    }
    fn push(&mut self, elem: &Element<Self::Space>) -> RlstResult<()> {
        self.inner.push(elem)
    }
    fn pop(&mut self) -> Option<Element<'a, Self::Space>> {
        self.inner.pop()
    }
    fn clear(&mut self) {
        self.inner.clear();
    }
}

impl<'a> FrameApply<'a> for ObservedFrameImpl<'a> {
    fn apply<A>(&self, coefficients: &Array<A, 1>) -> RlstResult<Element<'a, Self::Space>>
    where
        A: Shape<1> + UnsafeRandom1DAccessByValue<Item = f64>,
    {
        self.apply_calls.set(self.apply_calls.get() + 1);
        self.inner.apply(coefficients)
    }

    fn apply_into<A>(
        &self,
        alpha: f64,
        coefficients: &Array<A, 1>,
        beta: f64,
        output: &mut Element<Self::Space>,
    ) -> RlstResult<()>
    where
        A: Shape<1> + UnsafeRandom1DAccessByValue<Item = f64>,
    {
        self.apply_into_calls.set(self.apply_into_calls.get() + 1);
        self.inner.apply_into(alpha, coefficients, beta, output)
    }
}

impl<'a> FrameQr<'a> for ObservedFrameImpl<'a> {
    fn qr_pivoted(
        &self,
        options: FrameQrOptions<f64>,
    ) -> RlstResult<FrameQrDecomposition<Self, f64>> {
        self.qr_calls.set(self.qr_calls.get() + 1);
        let result = self.inner.qr_pivoted(options)?;
        Ok(FrameQrDecomposition {
            q: Self::new(result.q, self.generation + 1),
            r: result.r,
            permutation: result.permutation,
        })
    }
}

#[test]
fn wrapper_preserves_backend_overrides_through_inherent_and_trait_methods() {
    let space = ArrayVectorSpace::<f64>::new(2);
    let mut frame = ElementFrame::new(ObservedFrameImpl::new(GenericFrameImpl::new(&space), 7));
    assert!(frame.is_empty());
    assert!(FrameImpl::is_empty(&frame));
    assert_eq!(frame.imp().is_empty_calls.get(), 2);
    let mut element = space.zero();
    element.imp_mut()[[0]] = 2.0;
    frame.push(&element).unwrap();
    let coefficients = SliceArray::from_shape(&[3.0], [1]);
    assert_eq!(frame.apply(&coefficients).unwrap().imp()[[0]], 6.0);
    assert_eq!(
        FrameApply::apply(&frame, &coefficients).unwrap().imp()[[0]],
        6.0
    );
    assert_eq!(frame.imp().apply_calls.get(), 2);

    let mut output = space.zero();
    frame
        .apply_into(2.0, &coefficients, 0.0, &mut output)
        .unwrap();
    assert_eq!(output.imp()[[0]], 12.0);
    FrameApply::apply_into(&frame, 1.0, &coefficients, 2.0, &mut output).unwrap();
    assert_eq!(output.imp()[[0]], 30.0);
    assert_eq!(frame.imp().apply_into_calls.get(), 2);
    assert_eq!(frame.imp().apply_calls.get(), 2);

    let qr = frame.qr_pivoted(FrameQrOptions::default()).unwrap();
    let _: &ElementFrame<'_, ObservedFrameImpl<'_>> = &qr.q;
    assert_eq!(qr.q.imp().generation, 8);
    assert!(std::ptr::eq(qr.q.space(), &space));
    assert_eq!(qr.permutation, vec![0]);
    assert!((&qr.q.apply(&qr.r.r().col(0)).unwrap() - &element).norm() < 1e-12);
    let qr = FrameQr::qr_pivoted(&frame, FrameQrOptions::default()).unwrap();
    assert_eq!(qr.q.imp().generation, 8);
    assert_eq!(frame.imp().qr_calls.get(), 2);
    assert!(
        frame
            .qr_pivoted(FrameQrOptions {
                atol: -1.0,
                rtol: 0.0
            })
            .is_err()
    );
    assert_eq!(frame.imp().qr_calls.get(), 3);
}

#[test]
fn implementation_access_and_extraction_preserve_storage() {
    let space = ArrayVectorSpace::<f64>::new(2);
    let mut backend = ArrayFrameImpl::new(&space);
    backend.push(&space.zero()).unwrap();
    let pointer = backend.matrix().data().unwrap().as_ptr();
    let mut frame = ElementFrame::new(backend);
    assert_eq!(frame.matrix().data().unwrap().as_ptr(), pointer);
    frame.imp_mut().column_mut(0).unwrap()[[1]] = 42.0;
    assert_eq!(frame.column(0).unwrap()[[1]], 42.0);
    let mut backend = frame.into_imp();
    assert_eq!(backend.matrix().data().unwrap().as_ptr(), pointer);
    assert_eq!(backend.pop().unwrap().imp()[[1]], 42.0);

    let mut generic = ElementFrame::new(GenericFrameImpl::new(&space));
    generic.imp_mut().push(&space.zero()).unwrap();
    assert_eq!(generic.len(), 1);
    let backend = generic.into_imp();
    assert_eq!(backend.iter().count(), 1);
}

#[test]
fn storage_does_not_require_application_or_inner_products() {
    let space = ArrayVectorSpace::<i64>::new(2);
    let mut frame = ElementFrame::new(ArrayFrameImpl::new(&space));
    let mut element = space.zero();
    element.imp_mut()[[1]] = 9;
    frame.push(&element).unwrap();
    assert_eq!(frame.pop().unwrap().imp()[[1]], 9);
    assert!(frame.is_empty());
}

#[test]
fn wrapper_forwards_reference_access_to_the_backend() {
    let space = ArrayVectorSpace::<f64>::new(2);
    let mut inner = GenericFrameImpl::new(&space);
    let mut element = space.zero();
    element.imp_mut()[[0]] = 7.0;
    inner.push(&element).unwrap();
    let mut frame = ElementFrame::new(ObservedFrameImpl::new(inner, 0));

    assert_eq!(frame.element_ref(0).unwrap().imp()[[0]], 7.0);
    assert!(frame.element_ref(1).is_none());
    frame.element_mut(0).unwrap().imp_mut()[[0]] = 8.0;
    assert_eq!(frame.iter().next().unwrap().imp()[[0]], 8.0);
    for elem in frame.iter_mut() {
        elem.imp_mut()[[0]] += 1.0;
    }
    assert_eq!(frame.element_ref(0).unwrap().imp()[[0]], 9.0);

    // Two `element_ref`, one `element_mut`, one `iter`, one `iter_mut`, and the
    // final `element_ref`: every call reached the backend.
    assert_eq!(frame.imp().ref_calls.get(), 6);
}