https://codingspirit.de/dokuwiki/ 2026-04-27T21:29:48+00:00 https://codingspirit.de/dokuwiki/ https://codingspirit.de/dokuwiki/lib/exe/fetch.php?media=wiki:dokuwiki.svg text/html 2023-01-08T20:24:28+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:bitmagic&rev=1673209468&do=diff Bit-Magic Hacker's Delight * Official Website * <https://web.archive.org/web/20190915025154/http://www.hackersdelight.org/> * contains Errata and C code * Book as PDF - in images * <https://doc.lagout.org/security/Hackers%20Delight.pdf> * Wiki * <https://en.wikipedia.org/wiki/Hacker%27s_Delight> * Links, Copy of Code * <https://github.com/hcs0/Hackers-Delight> * <https://github.com/LucasForster/hackers-delight> HAKMEM * Wiki * <https://en.wikipedia.org/wiki… text/html 2023-12-26T04:28:05+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:converter&rev=1703564885&do=diff (Float)Number, RGB, Time and more converters References to external online converters * Binary/Decimal/Hex: * https://www.epochconverter.com/numbers/bin-oct-dec-hex * https://www.rapidtables.com/convert/number/index.html * bitwise (CLI) * IEEE-754 (Float/Double): * https://babbage.cs.qc.cuny.edu/ieee-754/ * RGB, Hex, CMYK, HSV, HSL, : * https://www.rapidtables.com/convert/color/rgb-to-hex.html * https://www.rapidtables.com/web/color/color-picker.html * https://ww… text/html 2023-12-26T05:09:45+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:cpp&rev=1703567385&do=diff C++ There are many interesting C++ sites and blogs. There's no need to repeat / copy the contents. Sites, Blogs and Books * hacking C++ * <https://hackingcpp.com/> * C++ and other development and devop themes * <https://www.bogotobogo.com/cplusplus/cpptut.php> * Fluent C++ * <https://www.fluentcpp.com/> * accu.org * contents for non-members * Abseil * <https://abseil.io/tips/> text/html 2022-12-24T22:11:54+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:fast_math&rev=1671919914&do=diff Fast/SIMD Linear/Trigonometric Math Notes Digital Signal Processing (DSP) is usually applied on streams, thus processed on signal blocks, consisting of a bunch of (complex) floating-point samples, e.g. with block size 256 .. 2048 samples. In the lab, a big signal file might be processed at once - similar to Octave/Matlab/NumPy/SciPy, but not when it comes to responsive realtime processing.$c(n)$$\sin()$$\cos()$$y(n) = x(n) \cdot c(n)$$x(n)$$c(n) = \exp(n \cdot i \cdot \Delta\varphi) = \cos(n \… text/html 2025-08-22T11:22:26+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:git&rev=1755861746&do=diff Git This is my git cheat-sheet, which grew with time .. cloning git clone git@github.com:/<GHUSER>/<PROJECT>.git git clone https://[<USER>:<PWD>@]github.com/<GHUSER>/<PROJECT> # only specific branch git clone --branch <BRANCH> git@github.com:/<GHUSER>/<PROJECT>.git # clone including submodules git clone --recursive git@github.com:/<GHUSER>/<PROJECT>.git git clone --recursive https://[<USER>:<PWD>@]github.com/<GHUSER>/<PROJECT> text/html 2023-08-14T20:09:13+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:numeric_math&rev=1692043753&do=diff Numeric / Math / Linear Algebra Numerically Robust Variance and weighted sum * John D. Cook's Accurately computing running variance * <https://kunalbandekar.blogspot.com/2011/03/algorithms-for-calculating-variance.html> * <https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance> * Welford algorithm * West algorithm * <https://en.wikipedia.org/wiki/Squared_deviations_from_the_mean> * <https://en.wikipedia.org/wiki/Kahan_summation_algorithm> * <https://www.ddj.com/f… text/html 2023-01-22T01:52:39+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:performance&rev=1674352359&do=diff Performance with C++ IEEE-754 Float Numbers as written in Numeric / Math / Linear Algebra, calculation with denormals or non-numbers slows down performance - even when not signalled. it might be interesting to abort a calculation, e.g. a matrix/vector multiplication, with first occurence of NaN - or with one of the other conditions .. text/html 2024-04-18T06:01:27+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:plotting&rev=1713420087&do=diff Plotting It's quite difficult - practically impossible - to perceive data from rows and columns with numerical data. This holds true for complex (scientific) data; but also for much simpler data, e.g. temperature records over time. Graphical plots allow fast perception. That makes plots very important - also for debugging while development. text/html 2022-12-24T21:49:07+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:simd&rev=1671918547&do=diff SIMD Modern processors have capabilities for SIMD (single instruction multiple data) like SSE or AVX instruction sets on x64 or NEON on ARM architecture. Now, in 2022, C/C++ compilers still have problems at automatic vectorization to generate these vector instructions. Assembler or compiler intrinsic functions can be used to enforce the usage .. text/html 2022-06-14T20:38:42+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:start&rev=1655239122&do=diff development index text/html 2023-01-08T20:24:02+00:00 Anonymous (anonymous@undisclosed.example.com) https://codingspirit.de/dokuwiki/doku.php?id=development:testing_and_prng&rev=1673209442&do=diff Testing, Reproducibility and Random Numbers General Software needs testing .. and many tests can be automized with unittests - or integration tests. The program/test should be reproducible to allow (later) debugging/fixing. Crash early! Especially when the program or it's results must be reliable,