use std::ops::AddAssign;
use anyhow::Error;
use num::{Float, FromPrimitive};
use crate::pert::PerturbationVectors;
use crate::utils::{mod_and_calc, mod_and_calc_const};
use super::OpFn;
pub fn forward_jacobian_const<const N: usize, const M: usize, F>(
x: &[F; N],
fs: OpFn<'_, N, M, F>,
) -> Result<[[F; N]; M], Error>
where
F: Float + FromPrimitive,
{
let fx = (fs)(x)?;
let mut xt = *x;
let eps_sqrt = F::epsilon().sqrt();
let mut out = [[F::from_f64(0.0).unwrap(); N]; M];
for i in 0..N {
let fx1 = mod_and_calc_const(&mut xt, fs, i, eps_sqrt)?;
for j in 0..M {
out[j][i] = (fx1[j] - fx[j]) / eps_sqrt;
}
}
Ok(out)
}
pub fn central_jacobian_const<const N: usize, const M: usize, F>(
x: &[F; N],
fs: OpFn<'_, N, M, F>,
) -> Result<[[F; N]; M], Error>
where
F: Float + FromPrimitive,
{
let mut xt = *x;
let eps_cbrt = F::epsilon().cbrt();
let mut out = [[F::from_f64(0.0).unwrap(); N]; M];
for i in 0..M {
let fx1 = mod_and_calc(&mut xt, fs, i, eps_cbrt)?;
let fx2 = mod_and_calc(&mut xt, fs, i, -eps_cbrt)?;
for j in 0..M {
out[j][i] = (fx1[j] - fx2[j]) / (F::from_f64(2.0).unwrap() * eps_cbrt);
}
}
Ok(out)
}
pub fn forward_jacobian_vec_prod_const<const N: usize, const M: usize, F>(
x: &[F; N],
fs: OpFn<'_, N, M, F>,
p: &[F; N],
) -> Result<[F; M], Error>
where
F: Float + FromPrimitive,
{
let fx = (fs)(x)?;
let eps_sqrt = F::epsilon().sqrt();
let mut x1 = [F::from_f64(0.0).unwrap(); N];
x1.iter_mut()
.enumerate()
.map(|(i, o)| *o = x[i] + eps_sqrt * p[i])
.count();
let fx1 = (fs)(&x1)?;
let mut out = [F::from_f64(0.0).unwrap(); M];
out.iter_mut()
.enumerate()
.map(|(i, o)| {
*o = (fx1[i] - fx[i]) / eps_sqrt;
})
.count();
Ok(out)
}
pub fn central_jacobian_vec_prod_const<const N: usize, const M: usize, F>(
x: &[F; N],
fs: OpFn<'_, N, M, F>,
p: &[F; N],
) -> Result<[F; M], Error>
where
F: Float + FromPrimitive,
{
let eps_cbrt = F::epsilon().cbrt();
let mut x1 = [F::from_f64(0.0).unwrap(); N];
let mut x2 = [F::from_f64(0.0).unwrap(); N];
x1.iter_mut()
.zip(x2.iter_mut())
.enumerate()
.map(|(i, (x1, x2))| {
let tmp = eps_cbrt * p[i];
*x1 = x[i] + tmp;
*x2 = x[i] - tmp;
})
.count();
let fx1 = (fs)(&x1)?;
let fx2 = (fs)(&x2)?;
let mut out = [F::from_f64(0.0).unwrap(); M];
out.iter_mut()
.enumerate()
.map(|(i, o)| {
*o = (fx1[i] - fx2[i]) / (F::from_f64(2.0).unwrap() * eps_cbrt);
})
.count();
Ok(out)
}
pub fn forward_jacobian_pert_const<const N: usize, const M: usize, F>(
x: &[F; N],
fs: OpFn<'_, N, M, F>,
pert: &PerturbationVectors,
) -> Result<[[F; N]; M], Error>
where
F: Float + FromPrimitive + AddAssign,
{
let fx = (fs)(x)?;
let eps_sqrt = F::epsilon().sqrt();
let mut xt = *x;
let mut out = [[F::from_f64(0.0).unwrap(); N]; M];
for pert_item in pert.iter() {
for j in pert_item.x_idx.iter() {
xt[*j] += eps_sqrt;
}
let fx1 = (fs)(&xt)?;
for j in pert_item.x_idx.iter() {
xt[*j] = x[*j];
}
for (k, x_idx) in pert_item.x_idx.iter().enumerate() {
for j in pert_item.r_idx[k].iter() {
out[*j][*x_idx] = (fx1[*j] - fx[*j]) / eps_sqrt;
}
}
}
Ok(out)
}
pub fn central_jacobian_pert_const<const N: usize, const M: usize, F>(
x: &[F; N],
fs: OpFn<'_, N, M, F>,
pert: &PerturbationVectors,
) -> Result<[[F; N]; M], Error>
where
F: Float + FromPrimitive + AddAssign,
{
let eps_cbrt = F::epsilon().cbrt();
let mut xt = *x;
let mut out = [[F::from_f64(0.0).unwrap(); N]; M];
for pert_item in pert.iter() {
for j in pert_item.x_idx.iter() {
xt[*j] += eps_cbrt;
}
let fx1 = (fs)(&xt)?;
for j in pert_item.x_idx.iter() {
xt[*j] = x[*j] - eps_cbrt;
}
let fx2 = (fs)(&xt)?;
for j in pert_item.x_idx.iter() {
xt[*j] = x[*j];
}
for (k, x_idx) in pert_item.x_idx.iter().enumerate() {
for j in pert_item.r_idx[k].iter() {
out[*j][*x_idx] = (fx1[*j] - fx2[*j]) / (F::from_f64(2.0).unwrap() * eps_cbrt);
}
}
}
Ok(out)
}
#[cfg(test)]
mod tests {
use crate::PerturbationVector;
use super::*;
const COMP_ACC: f64 = 1e-6;
fn f(x: &[f64; 6]) -> Result<[f64; 6], Error> {
Ok([
2.0 * (x[1].powi(3) - x[0].powi(2)),
3.0 * (x[1].powi(3) - x[0].powi(2)) + 2.0 * (x[2].powi(3) - x[1].powi(2)),
3.0 * (x[2].powi(3) - x[1].powi(2)) + 2.0 * (x[3].powi(3) - x[2].powi(2)),
3.0 * (x[3].powi(3) - x[2].powi(2)) + 2.0 * (x[4].powi(3) - x[3].powi(2)),
3.0 * (x[4].powi(3) - x[3].powi(2)) + 2.0 * (x[5].powi(3) - x[4].powi(2)),
3.0 * (x[5].powi(3) - x[4].powi(2)),
])
}
fn res1() -> [[f64; 6]; 6] {
[
[-4.0, 6.0, 0.0, 0.0, 0.0, 0.0],
[-6.0, 5.0, 6.0, 0.0, 0.0, 0.0],
[0.0, -6.0, 5.0, 6.0, 0.0, 0.0],
[0.0, 0.0, -6.0, 5.0, 6.0, 0.0],
[0.0, 0.0, 0.0, -6.0, 5.0, 6.0],
[0.0, 0.0, 0.0, 0.0, -6.0, 9.0],
]
}
fn res2() -> [f64; 6] {
[8.0, 22.0, 27.0, 32.0, 37.0, 24.0]
}
fn x() -> [f64; 6] {
[1.0f64, 1.0, 1.0, 1.0, 1.0, 1.0]
}
fn p() -> [f64; 6] {
[1.0f64, 2.0, 3.0, 4.0, 5.0, 6.0]
}
fn pert() -> PerturbationVectors {
vec![
PerturbationVector::new()
.add(0, vec![0, 1])
.add(3, vec![2, 3, 4]),
PerturbationVector::new()
.add(1, vec![0, 1, 2])
.add(4, vec![3, 4, 5]),
PerturbationVector::new()
.add(2, vec![1, 2, 3])
.add(5, vec![4, 5]),
]
}
#[test]
fn test_forward_jacobian_const_f64() {
let jacobian = forward_jacobian_const(&x(), &f).unwrap();
let res = res1();
for i in 0..6 {
for j in 0..6 {
assert!((res[i][j] - jacobian[i][j]).abs() < COMP_ACC)
}
}
}
#[test]
fn test_central_jacobian_const_f64() {
let jacobian = central_jacobian_const(&x(), &f).unwrap();
let res = res1();
println!("{:?}", jacobian);
for i in 0..6 {
for j in 0..6 {
assert!((res[i][j] - jacobian[i][j]).abs() < COMP_ACC);
}
}
}
#[test]
fn test_forward_jacobian_vec_prod_const_f64() {
let jacobian = forward_jacobian_vec_prod_const(&x(), &f, &p()).unwrap();
let res = res2();
for i in 0..6 {
assert!((res[i] - jacobian[i]).abs() < 11.0 * COMP_ACC)
}
}
#[test]
fn test_central_jacobian_vec_prod_const_f64() {
let jacobian = central_jacobian_vec_prod_const(&x(), &f, &p()).unwrap();
let res = res2();
for i in 0..6 {
assert!((res[i] - jacobian[i]).abs() < COMP_ACC)
}
}
#[test]
fn test_forward_jacobian_pert_const_f64() {
let jacobian = forward_jacobian_pert_const(&x(), &f, &pert()).unwrap();
let res = res1();
for i in 0..6 {
for j in 0..6 {
assert!((res[i][j] - jacobian[i][j]).abs() < COMP_ACC)
}
}
}
#[test]
fn test_central_jacobian_pert_const_f64() {
let jacobian = central_jacobian_pert_const(&x(), &f, &pert()).unwrap();
let res = res1();
for i in 0..6 {
for j in 0..6 {
assert!((res[i][j] - jacobian[i][j]).abs() < COMP_ACC)
}
}
}
}