/*!

\page double_nodes_page Duplicate Nodes

\n This operation allows to duplicate nodes of your mesh, which can be
useful to emulate a crack in the model.
Duplication consists in replacement of an existing mesh element by another one.
Lower level elements of the duplicated ones are cloned automatically. 

<em>To duplicate nodes:</em>
<ol>
<li>From the \b Modification menu choose \b Transformation -> \b Duplicate
\b Nodes item or click <em>"Duplicate Nodes"</em> button in the toolbar.
<br>
\image html duplicate_nodes.png "Duplicate Nodes button"
</li>
<li>Check in the dialog box one of two radio buttons corresponding to
the type of nodes duplication operation you would like to perform.</li>
<li>Fill the other fields available in the dialog box (depends on the chosen
 operation mode).</li>
<li>Click the \b Apply or <b>Apply and Close</b> button to perform the operation of nodes
 duplication.</li>
</ol>

\n "Duplicate Nodes" dialog has two working modes:
<ul>
<li>\ref mode_without_elem_anchor "Without the duplication of border elements"</li>
<li>\ref mode_with_elem_anchor "With the duplication of border elements"</li>
</ul>

<br>
\anchor mode_without_elem_anchor
<h2>Without duplication of border elements</h2>

In this mode the dialog looks like:

\image html duplicate01.png

Parameters to be defined in this mode:
<ul>
<li><b>Group of nodes to duplicate</b> (<em>mandatory</em>): these nodes will be duplicated.</li>
<li><b>Group of elements to replace nodes with new ones</b> (<em>optional</em>): the duplicated nodes
 will be associated with these elements.</li>
<li><b>Construct group with newly created nodes</b> option (<em>checked by default</em>): 
 if checked - the group with just created nodes will be built.</li>
</ul>

<br>
\anchor mode_with_elem_anchor
<h2>With duplication of border elements</h2>

In this mode the dialog looks like:

\image html duplicate02.png

Parameters to be defined in this mode:
<ul>
<li><b>Group of elements to duplicate</b> (<em>mandatory</em>): these elements will be duplicated.</li>
<li><b>Group of nodes at not to duplicate</b> (<em>optional</em>): group of nodes at crack bottom
 which will not be duplicated.</li>
<li><b>Group of elements to replace nodes with new ones</b> (<em>mandatory</em>): the duplicated nodes
 will be associated with these elements.</li>
<li><b>Construct group with newly created elements</b> option (<em>checked by default</em>): 
 if checked - the group of just created elements will be built.</li>
<li><b>Construct group with newly created nodes</b> option (<em>checked by default</em>): 
 if checked - the group of just created nodes will be built.</li>
</ul>


<br><b>See Also</b> a sample TUI Script of a \ref tui_duplicate_nodes "Duplicate nodes" operation.

*/