Merge pull request #1609 from lbl-srg/issue1587_kalmanFilterFix

Issue1587 kalman filter fix
lbl-srg · Oct 25, 2019 · d535f4d · d535f4d
2 parents 465b55a + a32f2cc
commit d535f4d
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Showing 4 changed files with 25 additions and 16 deletions.
diff --git a/Buildings/Resources/Python-Sources/KalmanFilter.py b/Buildings/Resources/Python-Sources/KalmanFilter.py
@@ -23,17 +23,16 @@ def filter(u):
     # Science, TR 95-041,
     # http://www.cs.unc.edu/~welch/kalman/kalmanIntro.html
     # by Andrew D. Straw
+    import json
     import os
-    import pickle
 
-    temporaryFile = "tmp-kalman.pkl"
+    temporaryFile = "tmp-kalman.json"
 
     # Read past observations from file, if the file exists
     # Otherwise, create a new array
     if os.path.exists( temporaryFile ):
-        pkl_file = open(temporaryFile, 'rb')
-        d = pickle.load(pkl_file)
-        pkl_file.close()
+        with open(temporaryFile, 'r') as fh:
+            d = json.load(fh)
         xhat = d['xhat']
         P    = d['P']
     else:
@@ -54,8 +53,7 @@ def filter(u):
 
     # Store observations to file for use in next iteration
     d = {'xhat': xhat, 'P': P}
-    pkl_file = open(temporaryFile, 'wb')
-    pickle.dump(d, pkl_file)
-    pkl_file.close()
+    with open(temporaryFile, 'w') as fh:
+        json.dump(d, fh)
 
     return xhat
diff --git a/Buildings/Resources/Scripts/BuildingsPy/conf.json b/Buildings/Resources/Scripts/BuildingsPy/conf.json
@@ -27,12 +27,6 @@
      "jmodelica": {
        "simulate": false
   },
-  "model_name": "Buildings.Utilities.IO.Python27.Examples.KalmanFilter"
-  },
-  {
-     "jmodelica": {
-       "simulate": false
-  },
   "model_name": "Buildings.Utilities.IO.Python27.Functions.Examples.Exchange"
   },
   {

diff --git a/Buildings/Utilities/IO/Python27/Examples/KalmanFilter.mo b/Buildings/Utilities/IO/Python27/Examples/KalmanFilter.mo
@@ -29,8 +29,8 @@ equation
  // Delete the temporary file generated by the Python file
  // at the start and end of the simulation.
  when {initial(), terminal()} then
-  Modelica.Utilities.Files.removeFile("tmp-kalman.pkl");
-end when;
+    Modelica.Utilities.Files.remove("tmp-kalman.json");
+ end when;
 
   connect(clock.y, ran.uR[1]) annotation (Line(
       points={{-59,10},{-42,10}},
@@ -84,6 +84,12 @@ http://www.scipy.org/Cookbook/KalmanFiltering</a>.
 </html>", revisions="<html>
 <ul>
 <li>
+October 24, 2019, by Antoine Gautier:<br/>
+Changed the temporary file format from <code>pickle</code> to <code>json</code> as the former can trigger a
+segfault with JModelica simulation run in a subprocess.<br/>
+This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/1587\">Buildings, #1587</a>.
+</li>
+<li>
 February 5, 2013, by Michael Wetter:<br/>
 First implementation.
 </li>

diff --git a/Buildings/package.mo b/Buildings/package.mo
@@ -299,6 +299,17 @@ its class name ends with the string <code>Beta</code>.
                            This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/1577\">1577</a>.
         </td>
     </tr>
+    <tr><td colspan=\"2\"><b>Buildings.Utilities</b>
+        </td>
+    </tr>
+    <tr><td valign=\"top\">Buildings/Resources/Python-Sources/KalmanFilter.py<br/>
+                           Buildings.Utilities.IO.Python27.Examples.KalmanFilter
+        </td>
+        <td valign=\"top\">Changed the temporary file format from <code>pickle</code> to <code>json</code> as the former can trigger a
+                           segfault with JModelica simulation run in a subprocess.<br/>
+                           This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/1587\">Buildings, #1587</a>.
+        </td>
+    </tr>
     </table>
     <!-- Uncritical errors -->
     <p>