Aug
28
Platon – nightly
After a long time of inactivity, I added fedora 16 and 17 for the nightly builds of platon. Fedora 16 Fedora 17
Aug
21
Sleef library – benchmark
The Sleef library is an optimised library for the calculation of mathematical functions: the trigonometric functions(sin, cos, tan, sincos), inverse trigonometric functions(asin, acos, atan, atan2), exponential and logarithmic functions(exp, log, pow, exp2, exp10, expm1, log10, log1p), hyperbolic/inverse hyperbolic functions(sinh, cosh, … Continue reading
Jun
26
Help vectorization of the code
The compiler gfortran is able to automatically vectorize part of the code. The flag “–ftree-vectorize” enable the auto-vectorization and some diagnostics are written on the screen at compile time with the flag “-ftree-vectorizer-verbose=x” (x is a number from 1 to … Continue reading
Jun
22
Speed up code with SIMD instructions
I previously talked the use of optimised trigonometric function through the use of the acml library. Trigonometric functions are coded in hardware through the x87 extension but it works on 80bits which is not necessary all the time. So software … Continue reading
Apr
24
Using geogebra for optics
New subject for this post. Since my new position at the crm2 in Nancy, I am working with optics. We set up an experiment on interferences and optical diffraction for demonstration. I am looking for a free open source software … Continue reading
Mar
09
High perfomance structure factors calculations
Part of a study on the standard deviation of the electron density using Monte Carlo simulations, I was needing a fast way to calculate structure factors. I achieve this goal a while ago but I continued to improve things each … Continue reading
Jan
20
Autovectorization
Vectorization is a nice concept in optimisation. It allows simulaneous calculations using special units in the processor. It is working only on special cases. I tried to apply to structure factors calculations. Fortran does not allow you to write vector … Continue reading
Jan
04
Platon nightly bug
A bug happened on the last December release of platon-nightly which was dated from 2012 instead of 2011. I forced the update (I increase the epoch tag) for the January release so that it will updated as usual.
Dec
13
Social integration – comments
I changed a few things in the settings of the blog. You have to be logged in to comment. No worry, you don’t need to create an account on Debroglie you can just login via facebook, twitter, google or linkedin. … Continue reading
Dec
10
Plotting libraries
Small reveiw and feelings about a few graphical libraries: gnuplot, matplotlib, pgplot, plplot, dislin and R. Continue reading