def get_constants_from_Y_G(y, g):
    """
    Calculates the remaining elastic quantities given the young's modulus (y),
    and the shear modulus (g)
    Returns:
         (dict): mapping from string symbol to float value
    """
    # Bulk modulus
    b = y * g / (3 * (3 * g - y))
    # Poisson Ratio
    v = y / (2 * g) - 1
    # Lame's First Parameter
    l = g * (y - 2 * g) / (3 * g - y)
    # P-Wave Modulus
    p = g * (4 * g - y) / (3 * g - y)
    return {"K": b, "v": v, "l": l, "M": p}