Generating the Input File
=========================

At this point, we have three simulation resources in our modelbuilder project: (i) a geometric model which was imported from PPG file; (ii) an attribute resource storing the simulation input data, in our example, material properties and constraint/load conditions; and (iii) a discretization (mesh) of the geometry model for the finite element calculations. The next step is to generate an input file in the format consumed the MinimalFEM solver. To do this, ModelBuilder-2D includes an *export operation*, which is implemented as a Python script that traverses the simulation resources and writes the input file in the correct format. (Look for the file ``MinimalFEM.py`` underneath the ModelBuilder-2D directory.) The use of the interpreted Python language allows applications to be customized without requiring compiled code.


.. rst-class:: step-number

16\. Export the Analysis

The process of generating the solver input file is referred to as *exporting* from modelbuilder to the solver-specific format. For this operation, the only user feedback are info messages writen to the :guilabel:`Output Messages` view indicating that the various operation steps were completed successfully. Before proceeding, click the :guilabel:`Clear` button below the :guilabel:`Output Messages` view to clear its current contents. Then generate the solver input file by going to the :guilabel:`CMB2D` menu and selecting the :guilabel:`Export Analysis` item. When you do this, ModelBuilder-2D will run the python script (``MinimalFEM.py``) which creates an ``export`` subfolder under your project folder and generates a file with the name ``minfem.inp`` in that folder. The script only takes a second to run. The resulting ``minfem.inp`` file is ascii, so you can load it into a text editor to view its contents if desired (but be sure not to make any changes!). It should be no surprise that most of the file consists of lists of mesh node coordinates and mesh element connectivity. In addition, the first line of the file contains the two elasticity parameters you entered, and the last 150 or so lines of the file specify the boundary conditions and load data you entered.