solve_grid3: Batched 3-parameter least squares over a grid

In mnirs: Muscle Near-Infrared Spectroscopy Processing and Analysis

Batched 3-parameter least squares over a grid

Description

Solves the normal equations of a 3-column linear model at every grid point at once, given the Gram entries ⁠g_ij = <c_i, c_j>⁠ and right-hand sides ⁠b_i = <c_i, x>⁠ as equal-shaped arrays (one element per grid point). Used by the self-start initialisers to profile the non-linear parameters on a grid without a per-point decomposition.

Usage

solve_grid3(g11, g12, g13, g22, g23, g33, b1, b2, b3, xx)

Arguments

g11, g12, g13, g22, g23, g33	Gram entries of the three basis columns.
b1, b2, b3	Inner products of the basis columns with the response.
xx	The response sum of squares ⁠<x, x>⁠.

Value

A list with the coefficient arrays c1, c2, c3 and the residual sum of squares rss, which is Inf where the system is singular.

mnirs documentation built on Sept. 13, 2026, 1:06 a.m.