For several years I have been running a mail server for me and my family plus some other services. The lack of monitoring has never really been an issue until recently. After migrating to a new VPS the clamd (antivirus) … Continue reading
Crystals is fully open source since a few years but building from source was always a tedious task. After many years, improvements have been made. The old Linux Makefiles and windows bat files have been replaced with cmake. The same … Continue reading
Since the apparition of area detectors, the storage of the frames resulting of the experiment has always been troublesome. The apparition of bigger and faster detectors increased the problem where a lots of big images are produced. Several methods exist … Continue reading
After looking at the Cholesky factorization problem, time to have a look at the eigenvalue decomposition of a symmetric matrix. Depending on the function and the blas library used, lots of differences appear. The functions which are benchmarked here are: … Continue reading
Crystals is using packed storage to store symmetric matrices. Packed storage is using a linear array to store only the unique data (Netlib packed storage). There is a huge penalty on the calculation by doing so in some cases. In … Continue reading
The compression scheme “byte offset” is commonly used in frames encoded in cbf. The Pilatus hybrid pixel detectors are using this format. The algorithm is descrived here: http://www.bernstein-plus-sons.com/software/CBF/doc/CBFlib.html#3.3 and a library already exist to manipulate cbf files called cbflib. The … Continue reading
As part of my new position in Oxford, I have a new computer: An 8-cores Intel Xeon CPU E5-2665 with 16GB of memory. Enough cores to try if my library is scaling well in multi-threaded environments. The result is really … Continue reading
The cryptic warning “not vectorized: not suitable for gather” is from a report of gfortran on auto-vectorization. For a long time, gfortran was reporting this failed optimization on a very simple mathematical operation. I managed to find the cause today … Continue reading
In the Crm² lab, in Nancy (France), we have prototype of an hybrid pixel detector from the company Imxpad. The data from the detector are raw ASCII files that I need to convert into files suitable for integration software. We … Continue reading
Moore’s law has driven computing power for years and will probably continue for sometime even though it ends is coming. However, if during the first 20 years the increasing power was directly related to the frequency, it’s no longer the … Continue reading