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  1. Adding text or graphics to a PDF file

    Using Acrobat Reader’s ability to add text et cetera has proven unreliable for me. On multiple occasions I have lost all the text added to a PDF file. When your filling in 20-plus pages worth of permit forms this is a huge waste of time and extremely annoying.

    So …

  2. Installing asymptote 2.38 in TeXLive 2016

    Since the previous article [1, 2] I’ve updated TexLive to 2016. This comes with asymptote 2.38, but not with a FreeBSD binary for it.

    My TeXLive is not installed from the FreeBSD ports tree, so I cannot use the asymptote port since it depends on the TeXLive port …

  3. Reading xlsx files with Python

    This article is a write-up of what I learned trying to extract information from ms-office xlsx files using Python.


    For my work I need to keep track of the hours that I spend on projects. Traditionally this is done on pre-printed paper sheets. This is somewhat cumbersome and the …

  4. Using a scanner for macro photography

    Although you wouldn’t guess it from the contents of this blog, my day job involves the design and production of products from fiber reinforced composites. A lot of my projects fall under non-disclosure agreements, so I cannot discuss them here.

    What I can do is share some of the …

  5. Using a Sony PRS-T2N e-reader with FreeBSD

    This article describes how to mount and transfer files to a Sony PRS-T2N.

    In an earlier article I reviewed the Sony PRS-T2N. It seems this model has now been replaced by the PRS-T3, and Sony has stopped making E-readers.

    Nevertheless I want to document how to mount …

  6. Checking links with linklint

    This website contains lots of external links. A fact of life is that hyperlinks are subject to change, so they need checking every now and then.

    In this how-to article I’ll cover how I did that for this website.

    While doing some checking on older articles on my weblog …

  7. Making a subset of a git repository

    Since I am in the process of making most of my programs available on github, I have been re-shuffling the some git repositories. Especially my collection of scripts (small programs for different purposes). Because some of those scripts are private, I don’t want to publish that repository as a …

  8. Making saline solution

    The standard recipe for saline solution is 9 grams of salt per liter of water.

    Since most people don’t have an accurate scale, we need to convert the nine grams to a volume. For that we need the bulk density of table salt. For fine table salt, the listed …

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