[cig-commits] r19156 - short/3D/PyLith/branches/v1.6-stable/doc/releasenotes

[brad at geodynamics.org]

Author: brad
Date: 2011-11-08 08:34:58 -0800 (Tue, 08 Nov 2011)
New Revision: 19156

Added:
   short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/announce_v1.6.2.txt
Modified:
   short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/Makefile.am
Log:
Added draft of release notes for v1.6.2.

Modified: short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/Makefile.am
===================================================================
--- short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/Makefile.am	2011-11-07 22:49:02 UTC (rev 19155)
+++ short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/Makefile.am	2011-11-08 16:34:58 UTC (rev 19156)
@@ -28,7 +28,9 @@
 	announce_v1.5.0.txt \
 	announce_v1.5.1.txt \
 	announce_v1.5.2.txt \
-	announce_v1.6.0.txt
+	announce_v1.6.0.txt \
+	announce_v1.6.1.txt \
+	announce_v1.6.2.txt
 
 
 # End of file 

Added: short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/announce_v1.6.2.txt
===================================================================
--- short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/announce_v1.6.2.txt	                        (rev 0)
+++ short/3D/PyLith/branches/v1.6-stable/doc/releasenotes/announce_v1.6.2.txt	2011-11-08 16:34:58 UTC (rev 19156)
@@ -0,0 +1,71 @@
+Greetings,
+
+I am pleased to announce the release of PyLith 1.6.2, a finite-element
+code designed to solve dynamic elastic problems and quasi-static
+viscoelastic problems in tectonic deformation.
+
+This release fixes several bugs in PyLith v1.6.1. We strongly
+recommend all users of previous PyLith releases switch to this latest
+release, especially anyone running in parallel or using fault friction.
+
+You can download the source code and binaries from
+
+    http://geodynamics.org/cig/software/packages/short/pylith
+
+Detailed installation instructions for the binary packages are in the
+User Manual with detailed building instructions for a few platforms
+in the INSTALL file bundled with the PyLith Installer utility.
+
+
+RELEASE NOTES
+
+* Internal changes
+
+  - Fault implementation
+
+    Several changes have been made to the fault implementation, but
+    none of these affect the user interface. The runtime performance
+    is nearly identical with improved accuracy for spontaneous rupture
+    (fault friction) simulations. These changes involved switching to
+    using tractions (non-integrated quantities) for the Lagrange
+    multipliers in the global coordinate system rather than integrated
+    quantities in the fault coordinate system. Additionally, initial
+    fault tractions are associated with the fault vertices and their
+    interpolation uses the finite-element basis functions.
+
+  - Distribution of mesh among processors
+
+    The data structures used to distribute the mesh among processors
+    have been improved. This reduces memory use and runtime for this
+    stage of the simulations.
+
+
+* Bug fixes
+
+  - Fixed bug in writing HDF5 files in parallel when one processor
+    does not write any information (e.g., faults and boundary
+    conditions).
+
+  - Added dimensioning of time dataset in HDF5 files. The units are
+    now seconds rather than nondimensional time.
+
+  - Fixed memory allocation error (std::bad_alloc) when a processor
+    did not contain cells for a boundary condition or output. This bug
+    did not show up on all architectures.
+
+  - Increased robustness of spontaneous rupture (fault friction)
+    implementation to broaden the range of conditions it can
+    handle. The implementation now properly handles cases with fault
+    opening and cases with zero shear or normal tractions.
+    
+
+KNOWN ISSUES
+
+  The custom line search used with the PETSc nonlinear solver (SNES)
+  has difficulty handling cases with fault opening when the fault
+  normal tractions are much larger than the fault shear tractions. The
+  direction of the line search tends to be nearly orthogonal to the
+  residual, resulting in extremely poor convergence. We plan to
+  improve the line search algorithm in a future release in order to
+  resolve this issue and improve the rate of convergence in
+  spontaneous rupture simulations.