When using native Windows Git client along with WSL Git, there can be nuisance dirty repo messages like:
old mode 100755
new mode 100644This problem is resolved for each Git client by executing in each of native Windows and WSL:
git config --global core.filemode falseFortran has a long legacy of preprocessing systems, reaching back at least to the 1970s when C was not yet widely known.
I would argue that modern Fortran ≥ 2008 has eliminated most preprocessors use cases.
It’s usually much cleaner and quicker (build/runtime) to use Fortran submodule to switch functionality such as
MKL vs. Atlas vs. Netlib Lapack
using CMake, for example.
Numerous Python preprocessors have arisen (and sunk) along with the usual C/C++-based preprocessors.
The only thing we use preprocessors for is very simple single-line statements, where adding a submodule would be significantly more cumbersome than a one-liner preprocessor statement.
Historically, very elaborate Fortran preprocessors were developed such that they nearly became a language unto themselves.
FLECS and Ratfor (also ratfiv, ratfor90, etc.)
These extensive preprocessors have been made obsolete by advances from Fortran 77 onward.
A few quick start tips for using EZNEC antenna design software for yagi antennas. This is assuming a yagi antenna for 440 MHz band.
How good is good enough?
SWR is a measure of how efficient an antenna is at coupling energy to/from the air to a radio device.
Γ = (SWR - 1) / (SWR + 1)
Suppose: SWR = 3.0
Power loss (gain) factors:
CMake by default searches for shared libs before static libs.
Sometimes a project needs to specifically link external or internal static libs, even if shared libs are present.
A simple cross-platform way to do this is to set
CMAKE_FIND_LIBRARY_SUFFIXES
before any find_library() or find_package():
set(CMAKE_FIND_LIBRARY_SUFFIXES .a .lib)This takes advantage of de facto static library extensions for macOS, Windows and Linux, using CMake system variables.
The default values for CMAKE_FIND_LIBRARY_SUFFIXES are set by (depending on platform and compiler) CMake
Modules/CMakeGenericSystem.cmake
Modules/Compiler/
Modules/Platform/Reading RINEX files in Python or other languages historically required compiling or buying complex software. The GeoRINEX Python 3 program and library to be used with RINEX OBS and NAV files, including Hatanaka compressed files or other compression wrappers like ZIP.
GeoRINEX can even read only every N seconds from a RINEX file with option georinex.load(..., interval=N).
This greatly speeds up reading where coarser time intervals than the RINEX file provides is needed.
GeoRINEX uses performance-oriented techniques to read RINEX files at speeds approaching compiled languages, using Pure Python + Numpy and Xarray for metadata rich results.
If you use GNSS and RINEX in your work, you may like GeoRINEX for Python 3.
For those dual-booting Windows and Linux, it’s useful to disable Windows Fast startup so that you can access the Windows partition from Linux. Disabling Fast Boot may add a few seconds to boot time. When you shutdown your PC, Fast Boot actually reboots and then hibernates. This locks the Windows partition so that Linux can’t access it.
Disable Fast Boot:
⊞+r
powercfg.cpl → “Choose what the power button does”.
We typically disable hibernate as well to save on SSD wear.
BitLocker and dual-booting: If BitLocker is enabled, Linux cannot access the Windows partition.
Fast Boot SSD wear: Fast Boot just like hibernate increases solid state drive (SSD) wear, since you are dumping an image ~ RAM size to disk on each Fast Boot shutdown.
Python
pathlib
is part of Python standard library.
When using Python
subprocess,
in general, do str(mypath) where type(mypath) is pathlib.Path.
Example:
#!/usr/bin/env python
from pathlib import Path
import subprocess
P = Path('~').expanduser()
O = subprocess.check_output(['dir', str(P)])
print(O)if you don’t cast pathlib.Path to str:
TypeError: argument of type ‘WindowsPath’ is not iterable.
You should rarely if ever need shell=True.
On Windows in particular, give the full path to a non-system executable.
Related: Idiomatic pathlib Python
Find and replace text in files recursively on Linux, macOS and
Windows Subsystem for Linux
with recursive_sed.sh:
#!/usr/bin/env bash
#
# The quoted variables allow using backticks and other "nasty" characters in sed.
#
# usage:
# ./recursive_sed.sh pathtofiles yuck yay
#
# References:
# https://stackoverflow.com/a/1585810
# https://unix.stackexchange.com/a/128758
set -o errexit
set -o nounset
path=$1
old=$2
new=$3
echo "${old} => ${new}"
find $path -not -path '*/.git*' -type f -execdir sed -i 's/'"${old}"'/'"${new}"'/g' {} +Pdoc is vastly simpler to use than Sphinx for small projects, with good HTML formatting.
In distinction from Sphinx, pdoc does not parse RST docstrings, but Pdoc does allow the following docstring formats:
At this time, pdoc3 doesn’t consider Python type hinting.
pdoc is a light minimal install.
pip install pdoc3We use the
pymap3d project
with auto-generated docs
as an example.
From the top-level pymap3d/ directory, type
pdoc --html pymap3dThis creates several *.html files under html/pymap3d, including index.html.
Check the output by:
firefox html/pymap3d/index.htmlIf the output seems satisfactory,
move the files to the gh-pages branch,
or at least to a docs/ folder:
mv html/pymap3d/*.html docs/Publish the docs to the web by:
Python users typically use a non-system Python distribution such as Miniconda. Python distributions typically allow easy switching of Python version. Where Linux system Python must be used, the default Python version can be switched persistently with update-alternatives.
Update-alternatives without sudo: a one-time setup.
Configure shell to use ~/.local/bin instead of system-wide /usr as follows:
mkdir ~/.local/binAdd to ~/.profile:
export PATH="$HOME/.local/bin:$PATH"Enable switching Python default between Python versions with these one-time commands:
update-alternatives --install $HOME/.local/bin/python python /usr/bin/python3 20After the setup above, at any time select the default system Python version without sudo:
update-alternatives --config python