.. role:: blue
   :class: blue

Constructing Two-Dimensional Cosine Wave
========================================
.. _Constructing_Two-Dimensional_Cosine_Wave_:

.. kernel version: 118058

The function  

.. code-block:: cpp

   MbResultType Cosinusoid( const MbCartPoint & point0,
                            const MbCartPoint & point1,
                                  MbCartPoint & point2,
                                  double        phase,
                                  double        waveLength,
                                  MbCurve *&    result );

constructs a cosine wave (two-dimensional harmonic curve).

Input parameters of the function are as follows:

- **point0** — an origin of the local coordinate system;
- **point1** — a point located on the X axis of the local coordinate system;
- **point2** — a point defining the Y axis of the local coordinate system;
- **phase** — a phase shift of the harmonic curve (in radians);
- **waveLength** — a wavelength of the harmonic curve.

The output parameter of the function is the pointer **result** to the constructed two-dimensional curve of type :blue:`MbCurve` representing the cosine wave.

If successful, the function returns :blue:`rt_Success`, otherwise it returns an error code from :ref:`MbResultType <MbResultType_>` enumeration.

The function is declared in *action_curve.h* file.

**point0**, **point1** and **point2** points define the local coordinate system of the cosine wave. **point0** will be the origin of the local coordinate system of the cosine wave, **axisX** of the local coordinate system will be directed from **point0** to **point1**, **axisY** of the local coordinate system will be orthogonal to **axisX** and directed from **point0** to **point2**.

**point0**, **point1** and **point2** points should not lie along a single straight line.

Two-dimensional cosine waves are described in Item :ref:`MbCosinusoid Two-Dimensional Cosine Wave <MbCosinusoid_Two-Dimensional_Cosine_Wave_>`.

The amplitude of the cosine wave is equal to the length of the projection of the vector (**point2** − **point0**) onto the Y axis **axisY**. The wavelength of the cosine wave is equal to **waveLength**. The number of waves of the cosine wave is determined by the distance between the points **point0** and **point1**.

**phase** defines the phase shift of the cosine wave:

.. figure:: /MODELER/TWO-DIMENSIONAL_CURVE_CONSTRUCTION_METHODS/pictures/M.3.6.1.png
   :width: 15cm
   :align: center