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Write kaleidocycle nudge in uniform coordinates

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In the previous commit, the nudge was written in standard coordinates,
so the example shouldn't have worked. However, by sheer dumb luck, the
standard and uniform coordinates match for this particular nudge. In
fact, the expression used before to get the standard coordinates may
even produce equivalent floating point values as the expression used
here to get the uniform coordinates. That would explain why the example
prints exactly the same output in this commit.
This commit is contained in:
Aaron Fenyes 2025-01-21 18:04:21 -08:00
parent a05a2e1d54
commit 01261aed91
1 changed files with 7 additions and 16 deletions
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23
app-proto/examples/kaleidocycle.rs
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@ -1,4 +1,4 @@
use nalgebra::DMatrix; use nalgebra::{DMatrix, DVector};
use std::{array, f64::consts::PI}; use std::{array, f64::consts::PI};
use dyna3::engine::{Q, point, realize_gram, PartialMatrix}; use dyna3::engine::{Q, point, realize_gram, PartialMatrix};
@ -59,22 +59,13 @@ fn main() {
println!("Loss: {}\n", history.scaled_loss.last().unwrap()); println!("Loss: {}\n", history.scaled_loss.last().unwrap());
// find the kaleidocycle's twist motion // find the kaleidocycle's twist motion
let up = DVector::from_column_slice(&[0.0, 0.0, 1.0, 0.0, 0.0]);
let down = -&up;
let twist_motion: DMatrix<_> = (0..N_POINTS).step_by(4).flat_map( let twist_motion: DMatrix<_> = (0..N_POINTS).step_by(4).flat_map(
|n| { |n| [
let up_field = { tangent.proj(&up.as_view(), n),
DMatrix::from_column_slice(5, 5, &[ tangent.proj(&down.as_view(), n+1)
0.0, 0.0, 0.0, 0.0, 0.0, ]
0.0, 0.0, 0.0, 0.0, 0.0,
0.0, 0.0, 0.0, 0.0, 1.0,
0.0, 0.0, 2.0, 0.0, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0
])
};
[
tangent.proj(&(&up_field * config.column(n)).as_view(), n),
tangent.proj(&(-&up_field * config.column(n+1)).as_view(), n+1)
]
}
).sum(); ).sum();
let normalization = 5.0 / twist_motion[(2, 0)]; let normalization = 5.0 / twist_motion[(2, 0)];
print!("Twist motion:{}", normalization * twist_motion); print!("Twist motion:{}", normalization * twist_motion);