Example for vector assignments

Added a new example which shows the most optimal way to assign vectors (or parts of vectors) to other vectors (or parts).

examples/vector_assignments.rs

@@ -0,0 +1,101 @@
+use nalgebra::{DVector, SVector};
+
+fn main() {
+    // Set full SVector (SV) to DVector (DV)
+    let (sv, mut dv) = (new_sv(), new_dv());
+    dv.copy_from(&sv);
+    assert_eq!(dv, SVector::<f32, 5>::new(0.0, 1.0, 2.0, 3.0, 4.0));
+
+    // Set full DV to SV
+    let (mut sv, dv) = (new_sv(), new_dv());
+    sv.copy_from(&dv);
+    assert_eq!(sv, SVector::<f32, 5>::new(0.0, 0.1, 0.2, 0.3, 0.4));
+
+    // Create new FV from another FV
+    let sv = new_sv();
+    let sv2: SVector<f32, 5> = sv; // SVector is Copy
+    assert_eq!(sv2, sv);
+
+    // Create new FV from another DV
+    let dv = new_dv();
+    let sv2: SVector<f32, 5> = dv.fixed_view::<5, 1>(0, 0).into();
+    assert_eq!(sv2, dv);
+
+    // Create new DV from another FV
+    let sv = new_sv();
+    let dv2: DVector<f32> = DVector::from_row_slice(sv.as_slice());
+    assert_eq!(dv2, sv);
+
+    // Create new DV from another DV
+    let dv = new_dv();
+    let dv2: DVector<f32> = dv.clone(); // DVector is only Clone
+    assert_eq!(dv2, dv);
+
+    // Set part of FV to another FV
+    let (mut sv, sv_sub) = (new_sv(), new_sv_sub());
+    *sv.fixed_view_mut::<3, 1>(1, 0) = *sv_sub;
+    assert_eq!(sv, SVector::<f32, 5>::new(0.0, 0.5, 1.5, 2.5, 4.0));
+
+    // Set part of FV to part of another FV
+    let (mut sv, sv_sub) = (new_sv(), new_sv_sub());
+    *sv.fixed_view_mut::<2, 1>(2, 0) = *sv_sub.fixed_view::<2, 1>(1, 0);
+    assert_eq!(sv, SVector::<f32, 5>::new(0.0, 1.0, 1.5, 2.5, 4.0));
+
+    // Set part of FV to another DV
+    let (mut sv, dv_sub) = (new_sv(), new_dv_sub());
+    *sv.fixed_view_mut::<3, 1>(1, 0) = *dv_sub.fixed_view::<3, 1>(0, 0);
+    assert_eq!(sv, SVector::<f32, 5>::new(0.0, 0.5, 1.5, 2.5, 4.0));
+
+    // Set part of FV to part of another DV
+    let (mut sv, dv_sub) = (new_sv(), new_dv_sub());
+    *sv.fixed_view_mut::<2, 1>(2, 0) = *dv_sub.fixed_view::<2, 1>(1, 0);
+    assert_eq!(sv, SVector::<f32, 5>::new(0.0, 1.0, 1.5, 2.5, 4.0));
+
+    // Set part of DV to another FV
+    let (mut dv, sv_sub) = (new_dv(), new_sv_sub());
+    dv.view_mut((1, 0), (3, 1)).copy_from(&sv_sub);
+    assert_eq!(dv, SVector::<f32, 5>::new(0.0, 0.5, 1.5, 2.5, 0.4));
+
+    // Set part of DV to part of another FV
+    let (mut dv, sv_sub) = (new_dv(), new_sv_sub());
+    dv.view_mut((2, 0), (2, 1))
+        .copy_from(&sv_sub.fixed_view::<2, 1>(1, 0));
+    assert_eq!(dv, SVector::<f32, 5>::new(0.0, 0.1, 1.5, 2.5, 0.4));
+
+    // Set part of DV to another DV
+    let (mut dv, dv_sub) = (new_dv(), new_dv_sub());
+    dv.view_mut((1, 0), (3, 1)).copy_from(&dv_sub);
+    assert_eq!(dv, SVector::<f32, 5>::new(0.0, 0.5, 1.5, 2.5, 0.4));
+
+    // Set part of DV to part of another DV
+    let (mut dv, dv_sub) = (new_dv(), new_dv_sub());
+    dv.view_mut((2, 0), (2, 1))
+        .copy_from(&dv_sub.view((1, 0), (2, 1)));
+    assert_eq!(dv, SVector::<f32, 5>::new(0.0, 0.1, 1.5, 2.5, 0.4));
+
+    // Set part of DV to part of another DV (alternative)
+    let (mut dv, dv_sub) = (new_dv(), new_dv_sub());
+    dv.view_mut((2, 0), (2, 1))
+        .copy_from(&dv_sub.fixed_view::<2, 1>(1, 0));
+    assert_eq!(dv, SVector::<f32, 5>::new(0.0, 0.1, 1.5, 2.5, 0.4));
+}
+
+// Create an example fixed sized vector with length 5
+fn new_sv() -> SVector<f32, 5> {
+    SVector::<f32, 5>::new(0.0, 1.0, 2.0, 3.0, 4.0)
+}
+
+// Create an example dynamically sized vector with length 5
+fn new_dv() -> DVector<f32> {
+    DVector::from_row_slice(&[0.0, 0.1, 0.2, 0.3, 0.4])
+}
+
+// Create an example fixed sized vector with length 3
+fn new_sv_sub() -> SVector<f32, 3> {
+    SVector::<f32, 3>::new(0.5, 1.5, 2.5)
+}
+
+// Create an example dynamically sized vector with length 3
+fn new_dv_sub() -> DVector<f32> {
+    DVector::from_row_slice(&[0.5, 1.5, 2.5])
+}