Add some more known issues related to El Capitan and the elliptical Gaussian model.

Jürgen Knödlseder
1 parent e7db1c12
Showing 1 changed file with 66 additions and 13 deletions
doc/source/issues.rst
@@ -5,11 +5,68 @@ Known issues
  
 Below you will find a list of known issues.
  
+**Installation issues**
+
+- :ref:`Certificate problem when cloning from Git <issue_ssl>`
+- :ref:`Python unit test fail on El Capitan <issue_elcapitan>`
+
+**Analysis issues**
+
+- :ref:`Binned analysis is biased for coarse binning <issue_binned>`
+
+**Model fitting issues**
+
 - :ref:`Broken power law has unreliable errors <issue_bplaw>`
 - :ref:`Errors become unreliable when fitting the pivot energy <issue_pivot>`
-- :ref:`Binned analysis is biased when using coarse binning <issue_binned>`
 - :ref:`Shell model is biased when width is comparable to angular resolution <issue_shell>`
+- :ref:`Elliptical Gaussian model fit converges slowly <issue_egauss>`
+
+
+Installation issues
+^^^^^^^^^^^^^^^^^^^
+
+.. _issue_ssl:
+
+.. topic:: Certificate problem when cloning from Git
+
+    When cloning ctools from git you may encounter an SSL certificate 
+    problem. This is related to the usage of the https protocol and can
+    be resolved by setting the ``GIT_SSL_NO_VERIFY`` environment variable
+    to true:
+
+    .. code-block:: bash
  
+       export GIT_SSL_NO_VERIFY=true
+ 
+.. _issue_elcapitan:
+
+.. topic:: Python unit test fail on El Capitan
+
+    On Mac OS X 10.11 (El Capitan) the Python unit tests fail when ctools 
+    are not installed due to the way the ``DYLD_LIBRARY_PATH`` environment
+    variable is handled by the operating system. A (not very elegant)
+    workaround is to install the ctools before running the unit test using 
+    ``make check``.
+
+
+Analysis issues
+^^^^^^^^^^^^^^^
+
+.. _issue_binned:
+
+.. topic:: Binned analysis is biased for coarse binning
+
+   When performing a binned or stacked analysis you should make sure
+   that the spatial and spectral binning is sufficiently fine grained.
+   The spatial binning should be better than the best angular resolution
+   over the energy range of interest. Use a typical value of 0.02 degrees
+   per pixel for the spatial binning and 10 bins per decade for the
+   spectral binning. If the binning is too coarse, the spectral parameters 
+   that are fitted will be biased.
+
+
+Model fitting issues
+^^^^^^^^^^^^^^^^^^^^
  
 .. _issue_bplaw:
  
@@ -35,18 +92,6 @@ Below you will find a list of known issues.
    parameters of the model to assure non-degeneracy of the free
    parameters.
  
-.. _issue_binned:
-
-.. topic:: Binned analysis is biased when using coarse binning
-
-   When performing a binned or stacked analysis you should make sure
-   that the spatial and spectral binning is sufficiently fine grained.
-   The spatial binning should be better than the best angular resolution
-   over the energy range of interest. Use a typical value of 0.02 degrees
-   per pixel for the spatial binning and 10 bins per decade for the
-   spectral binning. If the binning is too coarse, the spectral parameters 
-   that are fitted will be biased.
-
 .. _issue_shell:
  
 .. topic:: Shell model is biased when width is comparable to angular resolution
@@ -57,3 +102,11 @@ Below you will find a list of known issues.
    The fitted shell width and radius should thus not be overinterpreted
    when the width is close to the angular resolution of CTA.
  
+.. _issue_egauss:
+
+.. topic:: Elliptical Gaussian model fit converges slowly
+
+   The convergence of the elliptical Gaussian model can be slow and
+   in some situations requires of the order of 20 iterations before
+   the fit terminates. Nevertheless, the numerical accuracy of the model
+   fitting results are satisfactory.