Archiv der Kategorie: Software

The Apple Keynote Feature we have been waiting for

Apple updated last month Keynote with a feature we have been waiting for years – live video which is super cool to show live internet pages from active polls.


insert video only works from the top menu

There is no video source connected at the beginning but can can be added from the right side menu.

Unfortunately the virtual camera of OBS is not recognized but I could easily connect my Blackmagic Atem Mini so I have direct access to any source coming from a second computer running Chrome, Ipad with Sketchbook  and of course  the Z6 HDMI video signal.


adding the ATEM Mini from the right menu


A comparison of image duplication software

A quick comparison without pretending any objectivity

 Open SourceCommercial / Restricted AccessWebUpper Limit ImagesSpeedSensitivitySpecificityComment
Image Verification AssistantNNY1***
DiplopiaNNY>1000*****my own
SherloqYNN1*******good toolbox
TinEyeNYY*******full images only
max rating is ***

Geschützt: When a scientific journal is modifying your images

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False dichotomies

“The false dichotomy between private interest and public good” by

‘Good’ and ‘public benefit’ are subjective concepts and will vary according to individual perceptions and context. Private and public interest are inevitably intertwined and pitting them against each other creates a false dichotomy. For example, if patients cease to trust their clinicians or more broadly the NHS, public good will suffer. Furthermore, extensive exploration of public attitudes towards sharing medical data has found that people approve in general for their data to be used for medical research and for ‘good causes’, whether environmental, social or medical, but they do not approve of their data to be used for commercial purposes or for powerful companies to profit at society’s expense.

Finally I understand JS (a bit)

It produced a lot of headaches. And yes, it has been described already that

as a lot of articles I read about async in JavaScript, especially those that came out around the time ES2015 (ES6) was new, are just plain wrong. I’m going to clear up the falsehood by presenting a real understanding of the way async works in JavaScript.

Some nice examples are at and freecodecamp as well as a vid at youtube

At the end – I have some working code here, that shouldn’t work according to my understanding of concurrency.

How to monitor any website. At any time interval. With Telegram notification. For Free.

These instructions work for OSX Catalina only and are a bit different than the Linux version shown at urlwatch.

python3 -m pip install pyyaml minidb requests keyring appdirs lxml cssselect html2text
python3 -m pip install urlwatch
urlwatch --edit
# CTRL+X leave the editor without saving

Then edit ~/Library/Application Support/urlwatch/urls.yaml

kind: url
max_tries: 3
name: Camptoi
- element-by-id: product-desc-18713727425
- html2text:
    body_width: 0
    ignore_images: false
    ignore_links: false
    inline_links: false
    method: pyhtml2text
    pad_tables: false
    single_line_break: true
    unicode_snob: true

After that we create the Telegram bot by sending


to user BotFather and record the <API> from the response.

We also need to send a dummy message to the new bot so we can look up the sender <ID><API>/getUpdates

<API> and <ID> are both entered into ~/Library/Application Support/urlwatch/urlwatch.yaml

    bot_token: '<API>'
    chat_id: '<ID>'
    enabled: true

As we have no cron under MacOS we need a parameter file to run launchd. Should be placed at ~/Library/LaunchAgents/com.urlwatch.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
<plist version="1.0">

Ultimately, the agent is started (or stopped) using

launchctl load -w  ~/Library/LaunchAgents/com.urlwatch.plist               
launchctl unload ~/Library/LaunchAgents/com.urlwatch.plist

How to scrape a website with R II: WYSIWYG

Part II

Although Rselenium allows a screenshot of the current browser window

remDr <- remoteDriver(
  remoteServerAddr = "localhost",
  port = 4444,
  browserName = "Chrome"
remDr$screenshot(display = T) # remDr$screenshot(file="screen.jpg")

I found it extremely difficult to control a webbrowser running in a Docker container – looking up the DOM tree, injecting javascript etc is a lot of guess work.

So we need also a VNC server in the docker container as found at github.

After starting in the terminal

docker run -d -p 4444:4444 -p 5900:5900 -v /dev/shm:/dev/shm selenium/standalone-chrome:4.0.0-beta-1-prerelease-20210207

we can watch live at vnc:// what’s going on.

Sometimes it is better to switch bikes not gears

My 3 favorite programs? R, Bookends and Exposure.

The first choice is Rstudio (since 2012, being a long time SAS user). Here is the most recent JJ Allaire keynote


I was a bit with late with Bookends in 2018 (being a long time Sente user) but here is an introduction by Jon Ashwell.


And I am currently migrating to Exposure (after having used Lightroom for 13 years) by Jeff Butterworth


Life changes every day while it is sometimes better to switch bikes not gears.

Breaking up long chains in R’s margrittr code and calling sub functions

Having several long and redundant chains in R ‘s margittr code, I have now figured out how to pipe into named and unnamed functions

f1 <- function(x) {
  x %>% count() %>% print()
f2 <- function(x) {
  x %>% tibble() %>% print()

So we have now two named functions with code blocks that can be inserted in an unnamed function whenever needed

iris %>%
  # do any select, mutate ....
  # before running both functions
  (function(x) {
    x %>% select(Species) %>% f1() %>% print()
    x %>% f2() %>% print()

How to save a Twitter thread

This is not a trivial task as most browser produce garbage when printing to pdf. Also screenshots do not help so much with multipage threads. “Unroll” also doesn’t work reliable.

So I have been using the plugin before producing the pdf,  but this method is time consuming  as it needs a captcha.

Having now Selenium running in a docker container, there is a more convenient solution where  just two lines of R are sufficient

remDr$screenshot(file = 'screen.png')

Login is also possible as explained at github

username <- remDr$findElement(using = "name", value = "session[username_or_email]")
passwd <- remDr$findElement(using = "name", value = "session[password]")
passwd$sendKeysToElement(list("XXX", "\uE007"))

RKI Daten sind tages- und nicht fallbasiert

Leider kann man mit den RKI Daten nicht direkt in ein Regressionsmodell gehen, weil an vielen Tagen mehr als ein Fall in derselben Kategorie auftritt RKI Daten sind tages- und nicht fallbasiert weiterlesen

How to scrape a website with R I: Using a browser generated cookie

While there are quite some SO examples out there how to manage the login, here are the ncessary steps whenever you need to login in manually and have to start with a browser cookie. First install the “EditThisCookie” plugin in Chrome and export the cookie How to scrape a website with R I: Using a browser generated cookie weiterlesen

Better than a streamdeck: the Mac touchbar

I have been thinking to buy an Elgato Streamdeck as we have to lecture now also online during winter 2020.

While the Streamdeck mini would be a nice addition to the Elgato 4 K Camlink (that connects the Nikon) as well as the Epoc Cam software (that connects the Iphone) for easy switching input channels, I ultimately decided against this solution and just reconfigured the Touchbar for OBS using Better Touch Tool.