stefanschmidt

# Approximate the median of the standard half-normal distribution by
# computing the 75th percentile of the standard normal distribution using
# the algorithm from the original implementation of scipy.special.ndtri
#
# Based on the code from https://stackoverflow.com/questions/41338539#41338979
# which was based on the original implementation in ndtri.c

s2pi = 2.50662827463100050242E0

P0 = [

stefanschmidt

Gradually resolving symbolic link chains

Let's say one wants to know where pdflatex is located.

$ type pdflatex
pdflatex is /Library/TeX/texbin/pdflatex

We can see that this path is a symbolic link to pdftex.

$ ls -ld /Library/TeX/texbin/pdflatex

stefanschmidt

# cover (1 page)
# table of contents (14 pages)
# result: C1,i,ii,...,xiv,1,2,...
pip install pagelabels
python -m pagelabels --delete doc.pdf
python -m pagelabels --startpage 1 --prefix C doc.pdf
python -m pagelabels --startpage 2 --type 'roman lowercase' doc.pdf
python -m pagelabels --startpage 16 --type arabic doc.pdf

stefanschmidt

# show information about pdf resources (shows font names used in PDF)
mutool info file.pdf
# extract font and image resources
mutool extract file.pdf
# convert a CFF file (Compact Font Format) to OTF format (OpenType Font)
fontforge -lang=ff -c 'Open($1); Generate($1:r + ".otf")' font.cff

stefanschmidt

Simple linear regression in NumPy

The verbosity of performing a simple linear regression in the current stable release has increased by an astonishing amount.¹

In the documentation it is recommended to not use [numpy.polyfit][polyfit].

As noted above, the poly1d class and associated functions defined in numpy.lib.polynomial, such as numpy.polyfit and numpy.poly, are considered legacy and should not be used in new code. Since NumPy version 1.4, the numpy.polynomial package is preferred for working with polynomials.

For polynomial regression, the the documentation [recommends][polynomials] to replace [numpy.polyfit][polyfit] with [numpy.polynomial.polynomial.Polynomial.fit][polynomial].

stefanschmidt

Reading a CSV file with Python

For anything < 50 MB

import csv

with open("data.csv") as fp:
    reader = csv.reader(fp, delimiter=",", quotechar='"')
    csv_data = [row for row in reader]

stefanschmidt

Convert BBC subtitles to plain text

Install prerequisites

brew install youtube-dl
pip install pysrt beautifulsoup4
pip install --pre ttconv

Download the subtitles

stefanschmidt

Test with Chrome 112.0.5615.137 and uBlock Origin 1.49.2

Doesn't work (hides all divs)

www.google.com##div:has-text("It looks like there aren't many great matches for your search")
www.google.com##div:has-text(/It looks like there aren\'t many great matches for your search/)

Works

Use a more specific filter rule

Possibly because it narrows down the number of divs to consider.

stefanschmidt

Running ChromiumOS on macOS

The ChromiumOS distribution CloudReady was discontinued some time after Google acquired the company that offered it. The successor is ChromeOS Flex but there don't seem to be any official virtual machine images available.

Downloading the virtual machine image

The CloudReady OVA file mentioned in the knowledge base article is available on the Wayback Machine (direct download).

$ sha256sum CloudReady-Home-v83-x64.ova

7e4c7304c4b7363dfd778d3a58765c4d03fcd9fb3a1e5ae97c2582b42e4b66ad CloudReady-Home-v83-x64.ova

stefanschmidt

// ==UserScript==
// @name         Anti-Clickjacking
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  restore cmd+click on article links to open new tab
// @author       Stefan
// @match        https://www.technologyreview.com/
// @icon         https://www.technologyreview.com/static/media/favicon.1cfcdb44.ico
// @grant        none
// ==/UserScript==