home.md

+# Millepede-II
+
+## Introduction
+
+Millepede II is the successor of Millepede, a package for linear least squares fits with 
+a large number of parameters. Both have been developed as experiment independent programs
+by Prof. V. Blobel (Univ. Hamburg) primary for the alignment and calibration of tracking detectors. Documentation and source code of Millepede and of the first version
+of Millepede II are available on
+[his web page](http://www.desy.de/~blobel/mptalks.html) 
+(or [mirror](http://www.desy.de/~sschmitt/blobel/mptalks.html)).
+Meanwhile, the Statistics Tools group of the Analysis Centre of the Helmholtz
+[Terascale](http://terascale.de) Alliance took over the maintenance 
+of Millepede II.
+
+The first Analysis Centre release, version V02-00-01, contains V. Blobel's 2009 
+development and small changes/fixes coming from CMS experience by G. Flucke. 
+Further development, mainly by C. Kleinwort for usage in CMS, adds
+
+- auto-detection of bordered band matrices in the local fit to speed up processing if e.g.
+  fed with tracks fitted using the broken lines technique (cf.
+  [NIM A566:14-17,2006 by V. Blobel](http://www-library.desy.de/cgi-bin/spiface/find/hep/www?j=NUIMA,A566,14)
+  and *GeneralBrokenLines*),
+- the possibility to ignore or compress rare off-diagonal elements of the global matrix 
+  (to reduce space requirements),
+- shared-memory parallelisation of most parts of the code (track fits, MINRES, inversion) 
+  using [OpenMP™](http://openmp.org/wp),
+- the possibility to read gzipped C/C++ binaries,
+- further fixes/improvements not only from CMS experience.
+
+Using these features allows CMS silicon tracker alignment to determine 200 000 parameters 
+in one go fitting more than 20 million tracks, including 3.6 million cosmic ray tracks 
+and about 375 thousand muon pairs from Z decays reparametrised as one fit object with a 
+vertex constraint and adding a virtual Z mass measurement (cf. 
+[CMS-CR-2011-323](http://cdsweb.cern.ch/record/1406822)). 
+The computing requirements on an Intel™ Xeon™ L5520 with 2.27 GHz using eight threads are 
+44.5 h CPU (but only 10 h wall clock time) and less than 32 GB of RAM.
+
+## [Availability](availability)
+
+## [Compilation](compilation)
+
+## [Version history](history)
+
+## [Hardcoded limits](limits)
+
+## [Collection of users](users)
+
+## [References](references)
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