_phi

pmrf.models.components.lines.profiles._phi(x: Array | ndarray | bool | number | bool | int | float | complex, a: Array | ndarray | bool | number | bool | int | float | complex) → Array | ndarray | bool | number | bool | int | float | complex

Klopfenstein’s \(\phi(x, A)\), by Gauss-Legendre quadrature, elementwise in x.

The integration interval \([0, x]\) is mapped onto the rule’s \([-1, 1]\), so the whole of x is handled in one vectorised evaluation with no scan or loop.