def getFunction(LHStok, RHStok, eqnVars, graphVars, dim):
    """Returns function for plotting

    Arguments:
        LHStok {list} -- expression tokens
        RHStok {list} -- expression tokens
        eqnVars {list} -- variables in equation
        graphVars {list} -- variables for plotting
        dim {int} -- dimenion of plot

    Returns:
        (LHS - RHS) {numpy.array(2D)/function(3D)} -- equation converted to compatible data type for plotting
    """
    LHS = getFuncExpr(LHStok, eqnVars, graphVars)
    if len(eqnVars) == dim:
        RHS = getFuncExpr(RHStok, eqnVars, graphVars)
    elif len(eqnVars) == dim - 1:
        RHS = graphVars[-1]
    return LHS - RHS