#NEWLINE# def l2_norm( f , lim ) : #NEWLINE# #INDENT# '\n    Calculates L2 norm of the function "f", over the domain lim=(x, a, b).\n\n    x ...... the independent variable in f over which to integrate\n    a, b ... the limits of the interval\n\n    Examples\n    ========\n\n    >>> from sympy import Symbol\n    >>> from gibbs_phenomenon import l2_norm\n    >>> x = Symbol(\'x\', real=True)\n    >>> l2_norm(1, (x, -1, 1))\n    sqrt(2)\n    >>> l2_norm(x, (x, -1, 1))\n    sqrt(6)/3\n\n    ' #NEWLINE# return sqrt ( integrate ( ( Abs ( lim ) ** 2 ) , lim ) )