added SC's dyna handling (#108)

* added SC's dyna handling

* test for khandler

Author: e-dub

pygem/__init__.py

@@ -1,14 +1,15 @@
 __all__ = [
 	'affine', 'filehandler', 'freeform', 'radial', 'openfhandler', 'params',
 	'stlhandler', 'unvhandler', 'vtkhandler', 'nurbshandler', 'stephandler',
-	'igeshandler', 'utils', 'gui'
+	'igeshandler', 'utils', 'gui', 'khandler'
 ]
 
 from . import affine
 from . import filehandler
 from . import freeform
 from . import gui
 from . import igeshandler
+from . import khandler
 from . import nurbshandler
 from . import openfhandler
 from . import params

pygem/khandler.py

@@ -0,0 +1,87 @@
+"""
+Derived module from filehandler.py to handle LS-DYNA keyword (.k) files.
+"""
+import numpy as np
+import pygem.filehandler as fh
+
+
+class KHandler(fh.FileHandler):
+    """
+    LS-Dyna keyword file handler class
+
+    :cvar string infile: name of the input file to be processed.
+    :cvar string outfile: name of the output file where to write in.
+    :cvar list extensions: extensions of the input/output files. It is equal
+            to '.k'.
+    """
+    def __init__(self):
+        super(KHandler, self).__init__()
+        self.extensions = ['.k']
+
+    def parse(self, filename):
+        """
+        Method to parse the file `filename`. It returns a matrix with all the
+        coordinates. It reads only the section *NODE of the k files.
+
+        :param string filename: name of the input file.
+
+        :return: mesh_points: it is a `n_points`-by-3 matrix containing the
+                coordinates of the points of the mesh.
+        :rtype: numpy.ndarray
+        """
+        self._check_filename_type(filename)
+        self._check_extension(filename)
+        self.infile = filename
+        index = -9
+        mesh_points = []
+        with open(self.infile, 'r') as input_file:
+            for num, line in enumerate(input_file):
+                if line.startswith('*NODE'):
+                    index = num
+                if num == index + 1:
+                    if line.startswith('$'):
+                        index = num
+                    elif line.startswith('*'):
+                        index = -9
+                    else:
+                        l = []
+                        l.append(float(line[8:24]))
+                        l.append(float(line[24:40]))
+                        l.append(float(line[40:56]))
+                        mesh_points.append(l)
+                        index = num
+            mesh_points = np.array(mesh_points)
+        return mesh_points
+
+    def write(self, mesh_points, filename):
+        """
+        Writes a .k file, called filename, copying all the lines from
+        self.filename but the coordinates. mesh_points is a matrix that
+        contains the new coordinates to write in the .k file.
+
+        :param numpy.ndarray mesh_points: it is a `n_points`-by-3 matrix
+                          containing the coordinates of the points of the mesh
+        :param string filename: name of the output file.
+        """
+        self._check_filename_type(filename)
+        self._check_extension(filename)
+        self._check_infile_instantiation()
+        self.outfile = filename
+        index = -9
+        i = 0
+        with open(self.outfile, 'w') as output_file:
+            with open(self.infile, 'r') as input_file:
+                for num, line in enumerate(input_file):
+                    if line.startswith('*NODE'):
+                        index = num
+                    if num == index + 1:
+                        if line.startswith('$'):
+                            index = num
+                        elif line.startswith('*'):
+                            index = -9
+                        else:
+                            for j in range(0, 3):
+                                line = line[:8+16*(j)] + '{:16.10f}'.format(mesh_points[i][j]) + line[8+16*(j+1):]
+                            i += 1
+                            index = num
+                    output_file.write(line)