def calc_lims(val_min=False, val_max=False, offset=False):
    """
    Gives back an optimal limit for an plot upper or lower value. Therefor, it uses an inbuild offset from the PROFILE.
    """
    from pen.profiles import get
    import numpy as np
    import math

    if not offset:
        offset = get()["ax_xylim_moffset"]

    if not isinstance(val_min, (bool)):
        if val_min == 0.0:
            return 0.0

        val_min = float(val_min - offset * np.abs(val_min))

        e = int(math.log10(abs(val_min)))
        if e < 0:
            e = e - 1
        M = val_min / (10 ** e)
        val_min = np.floor(M * 10.0) / 10.0 * 10 ** e

        return val_min

    if not isinstance(val_max, (bool)):
        if val_max == 0.0:
            return 0.0

        val_max = float(val_max * 1.0 + offset * np.abs(val_max))

        e = int(math.log10(abs(val_max)))
        if e < 0:
            e = e - 1
        M = val_max / (10 ** e)
        val_max = np.ceil(M * 10.0) / 10.0 * 10 ** e

        return val_max

    return False