.. _elementWiseHW:

Element-wise Arithmetic
===============================

Write a function called poly_val that is called like this ``p =
poly_val(c0,c,x)``, where ``c0`` and ``x`` are scalars,
and ``p`` is a scalar. If ``c`` is an empty vector, then ``p = c0``. If
``c`` is a scalar, then ``p = c0 + c*x`` . Otherwise, ``p`` equals the
polynomial,

.. math:: c_0 + c_1x + c_2x^2 + \cdots + c_nx^n

where ``n`` is the length of the vector ``c``. 

Hints:

#. The functions ``isempty``, ``isscalar``, ``iscolumn``, and ``length``
   will tell you everything you need to know about the vector ``c``.

#. When ``c`` is a vector, use an element-wise exponent to determine
   the vector :math:`[x \: x^2 \: x^3\, \cdots\, x^n]`.

#. When ``c`` is a vector, use the ``sum`` function with element-wise
   multiplication. Matrix multiplication could also be used, but we have not
   yet covered that.
   
Here are three example runs::

    >> p = poly_val(-17,[],5000)
    p =
      -17
    >> p = poly_val(3.2,[3,-4,10],2.2)
    p =
       96.9200
    >> p = poly_val(1,[1;1;1;1],10)
    p =
       11111
    >> p = poly_val(8,5,4)
    p =
        28

`MATLAB Grader Element-wise assignment page
<https://grader.mathworks.com/courses/115347-applied-data-analysis-and-tools-fall-2024/assignments/315717-element-wise-arithmetic>`_.

.. raw:: latex

    \clearpage