FEM: Add simple dat file reader

It's a simple CalculiX dat file reader used to extract eigenmode
frequencies after freqyency analysis.

Signed-off-by: Przemo Firszt <przemo@firszt.eu>

src/Mod/Fem/App/CMakeLists.txt

@@ -69,6 +69,7 @@ SOURCE_GROUP("Module" FILES ${Mod_SRCS})
 
 SET(FemScripts_SRCS
     convert2TetGen.py
+    ccxDatReader.py
     ccxFrdReader.py
     ccxInpWriter.py
     TestFem.py

src/Mod/Fem/CMakeLists.txt

@@ -10,6 +10,7 @@ INSTALL(
         Init.py
         InitGui.py
         convert2TetGen.py
+        ccxDatReader.py
         ccxFrdReader.py
         ccxInpWriter.py
         FemTools.py

src/Mod/Fem/ccxDatReader.py

@@ -0,0 +1,89 @@
+#***************************************************************************
+#*   Copyright (c) 2015 - FreeCAD Developers                               *
+#*   Author: Przemo Firszt <przemo@firszt.eu>                              *
+#*                                                                         *
+#*   This program is free software; you can redistribute it and/or modify  *
+#*   it under the terms of the GNU Lesser General Public License (LGPL)    *
+#*   as published by the Free Software Foundation; either version 2 of     *
+#*   the License, or (at your option) any later version.                   *
+#*   for detail see the LICENCE text file.                                 *
+#*                                                                         *
+#*   This program is distributed in the hope that it will be useful,       *
+#*   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+#*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+#*   GNU Library General Public License for more details.                  *
+#*                                                                         *
+#*   You should have received a copy of the GNU Library General Public     *
+#*   License along with this program; if not, write to the Free Software   *
+#*   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
+#*   USA                                                                   *
+#*                                                                         *
+#***************************************************************************
+
+
+import FreeCAD
+import os
+
+__title__ = "ccxDatReader"
+__author__ = "Przemo Firszt"
+__url__ = "http://www.freecadweb.org"
+
+
+if open.__module__ == '__builtin__':
+    # because we'll redefine open below
+    pyopen = open
+
+EIGENVALUE_OUTPUT_SECTION = "     E I G E N V A L U E   O U T P U T"
+
+
+# read a calculix result file and extract the data
+def readResult(dat_input):
+    dat_file = pyopen(dat_input, "r")
+    eigenvalue_output_section_found = False
+    mode_reading = False
+    results = []
+
+    for line in dat_file:
+        if EIGENVALUE_OUTPUT_SECTION in line:
+            # Found EIGENVALUE_OUTPUT_SECTION
+            eigenvalue_output_section_found = True
+        if eigenvalue_output_section_found:
+            try:
+                mode = int(line[0:7])
+                mode_frequency = float(line[39:55])
+                m = {}
+                m['eigenmode'] = mode
+                m['frequency'] = mode_frequency
+                results.append(m)
+                mode_reading = True
+            except:
+                if mode_reading:
+                    # Conversion error after mode reading started, so it's the end of section
+                    eigenvalue_output_section_found = False
+                    mode_reading = False
+
+    dat_file.close()
+    return results
+
+
+def import_dat(filename, Analysis=None):
+    r = readResult(filename)
+    #print ("Results {}".format(r))
+    return r
+
+
+def insert(filename, docname):
+    "called when freecad wants to import a file"
+    try:
+        doc = FreeCAD.getDocument(docname)
+    except NameError:
+        doc = FreeCAD.newDocument(docname)
+    FreeCAD.ActiveDocument = doc
+
+    import_dat(filename)
+
+
+def open(filename):
+    "called when freecad opens a file"
+    docname = os.path.splitext(os.path.basename(filename))[0]
+    insert(filename, docname)