Source code for torx.geometry.shrink_rectangle_m

"""
Utilities for shrinking rectangular boundaries inward by a fractional margin.

Useful for computing grid limits that avoid interpolation errors near domain edges.
"""
import numpy as np



def shrink_rectangle(
    r_min: float,
    r_max: float,
    z_min: float,
    z_max: float,
    factor: float = 0.01,
) -> tuple[float, float, float, float]:
    """
    Shrink a rectangle inward by a fraction of its extent.

    Returns (r_min, r_max, z_min, z_max).
    """
    r_extent = r_max - r_min
    z_extent = z_max - z_min

    return (
        r_min + factor * r_extent,
        r_max - factor * r_extent,
        z_min + factor * z_extent,
        z_max - factor * z_extent,
    )




def shrink_grid(
    r_points: np.ndarray,
    z_points: np.ndarray,
    factor: float = 0.01,
) -> tuple[float, float, float, float]:
    """
    Call shrink_rectangle with inferring bounds from grid arrays.

    Returns (r_min, r_max, z_min, z_max).
    """
    return shrink_rectangle(
        r_min=float(np.min(r_points)),
        r_max=float(np.max(r_points)),
        z_min=float(np.min(z_points)),
        z_max=float(np.max(z_points)),
        factor=factor,
    )