%feature("docstring") OT::DualLinearCombinationFunction
"Linear combination of functions with vectorial weights.

Allows to create a function which is the linear combination
of scalar functions with vectorial weights.

:math:`functionCollection  = (f_1, \hdots, f_N)`
where :math:`\forall 1 \leq i \leq N, \,     f_i: \Rset^n \rightarrow \Rset`
and :math:`scalarCoefficientColl = (\vect{c}_1, \hdots, \vect{c}_N), \vect{c}_i \in \Rset^p`
then the linear combination is:

.. math::

    vectLinComb  \left|\begin{array}{rcl}
                  \Rset^n & \rightarrow & \Rset^{p} \\
                  \vect{X} & \mapsto & \displaystyle \sum_{i=1}^N \vect{c}_i f_i (\vect{X})
              \end{array}\right.

Parameters
----------
functionCollection : sequence of :class:`~openturns.Function`
    Collection of functions.
vectorCoefficientColl : 2-d sequence of float
    Collection of vectorial weights.

Examples
--------
>>> import openturns as ot
>>> f1 = ot.SymbolicFunction(['x1', 'x2', 'x3'],
...                          ['x1 + 2 * x2 + x3'])
>>> f2 = ot.SymbolicFunction(['x1', 'x2', 'x3'],
...                          ['x1^2 + x2'])
>>> functions = [f1, f2]
>>> coefficients = [[2.0, 4.0], [3.0, 1.0]]
>>> vectLinComb = ot.DualLinearCombinationFunction(functions, coefficients)
>>> print(vectLinComb([1, 2, 3]))
[25,35]
"
