Author Archives: pauljohn

About pauljohn

Paul E. Johnson is a Professor of Political Science at the University of Kansas. He is an avid Linux User, an adequate system administrator and C programmer, and humility is one of his greatest strengths.

Building R-4.0.0 in a side folder

R 4.0 was released over the weekend and immediately I got an email that said one of my packages does not build anymore with R-4.0. The email from R core said I have 2 weeks to bring the package into … Continue reading

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Creating a new SSH key with ed25519 encryption

A while ago, I prepared notes about creating an SSH key for use with Gitlab (and other SSH-based servers). That guide, , explains the basic ideas of SSH keys. Today I learned that when interacting with an SSH server, … Continue reading

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R package semTable-1.7 uploaded on CRAN

semTable-1.7 includes a bug fix for tables that include variances estimated between latent variables and exogenous predictors. It has been proposed to CRAN. In the meanwhile, to avail yourselves, try this to put KRAN (our test server) at the front … Continue reading

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Does mathjax-latex work? Not entirely if Markdown is enabled.

I have updated to PhP 7.2 FastCGI and WordPress 5.2. I want to use WordPress to display markdown documents that have some latex, so I’ve installed a plugin for markdown which seems to work. However, I’m getting mixed results with … Continue reading

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Finding and Recovering lost files in Git

One problem in git is that when a user deletes a file accidentally, git acts as though the user intended to do that. The next time the user runs “git commit -a” then the list of transactions will include the … Continue reading

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Building a new xfwm4 Debian package: Try it, you’ll like it!

In the askubuntu web forum (, I asked if it is possible to change the behavior of the mouse in response to  Alt-Middle click. Currently, that causes a window to be moved to the bottom of the stack of windows. … Continue reading

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Building R-devel on RedHat Linux 6

  Warning: I’m 85% done with this, formatting is not right. I DO NOT want to type in the prompt in front of every command because then one cannot copy/paste directly.  However, copying some output chunks picks up the dollar … Continue reading

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New lifescape panorama

  Today, I was struck by the beauty of the desert on a crystal clear morning. As the panorama below  indicates, there is no apparent sign of life in this seemingly barren, desolate part of the high plains. Only the … Continue reading

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Time Series tips for R users

Two people were in here last week asking me about time series modeling in R. I said I’d look something up. I thought this was fabulously helpful for translating between R and time series books: The leading authority on … Continue reading

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Get out of fail2ban jail

Ever get locked out of your own computer because you tried the password too many times when you were, well, not paying attention? I found it tough to find how to unban myself and was pretty frustrated by the ambiguity … Continue reading

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