I like the Kate editor, so I write this post to list all of my settings to make it usable as a data science environment (for R / Python). This guide relies on the VI editing mode of Kate, which may not be for everyone (however, I am a VI noob myself). I explain some optimizations for writing in Kate (e.g., filling paragraphs) and how to submit code to the (R or Python) console.

General settings

These are my (non-data-science) related configurations.

Activate VI mode

  • Activate VI mode in Configure Kate -> Editing
  • Activates the feature that VI commands replace Kate commands
  • Unfortunately, the search mode no longer fulfills my needs with VI mode activated, because only the next occurrence of a pattern can be searched. So I bound CTRL-f to “Search and Replace” rather than ordinary Search. This even has some advantages, as this search option directly shows all matches and can also be used to search in multiple files.

Hard line breaks

As I prefer hard versus soft linebreaks when writing, for example R Markdown documents, I need some functionality for hard line breaks. In my opinion, emacs has the best option for hard line breaks with the fill paragraph option. I have not seen this option in any other text editor so far. However, I found out how to emulate this functionality in Kate:

  • Add key bindings for VI in Configure Kate -> Editing -> VI editing
  • In normal mode, add the following key binding:
    • <a-q>: mz { j V } k gq `z. This adds the fill paragraph option to ALT-Q key binding in VI normal mode
  • In Insert mode use <esc> mz { j V } k gq `z i. That is, wrap ESC and i around the command to leave and re-enter visual mode.
  • If only one line needs to be “broken”, you can use the Kate keybinding for “Apply word wrap” (Settings -> Configure Shortcuts -> Apply Word Wrap), e.g.  use CTRL-ALT-Q

One problem is that this keybinding sets a vim mark, which in turn converts to a Kate bookmark. So I added a Kate keybinding for clearing all bookmarks (CRTL-ALT-M), which can be appended to the above command. This implies that the fill paragraph command removes all of your marks, but I guess this is not terribly important (for me, at least).

  • For normal mode, this leaves:
    • mz { j V } k gq `z<c-a-m>
  • For insert mode, this leaves:
    • <esc> mz { j V } k gq`z<c-a-m>i

This way, I can mostly reproduce the emacs fill paragraph command. There is one caveat however: If I use fill paragraph in insert mode and the cursor is at the end of the current line, the cursor sometimes moves back one character. Maybe this can be fixed somehow, not sure.

Fonts

  1. Create a new scheme for fonts that can be adapted
  2. Change the font to Ubuntu Mono 14pt (so beautiful <3)
  3. Change the color in Documentation -> Annotation and Comment Variable to something more colorful (something that is easily recognized among grey comment font)

Konsole

Kate requires that the KDE terminal konsole is available. On non-KDE desktops this may need to be installed, on Ubuntu for example with.

$ sudo apt install konsole

Next, some configurations for the terminal.

  • Deactivate Synchronize Terminal with Current Document in the settings. This is crucial to prevent the terminal trying to cd to the directory of every document that is opened, which raises an erron when you are in the python or R console.
  • Move the terminal to the right of Kate (via right click on the terminal button below).
  • Open the terminal, right click and choose Edit current profile to change the appearance of the terminal to your liking. In the terminal, we will start the R or python consoles, as explained below.

Using Kate as Data Science IDE

In this section, I describe the functionalities of Kate making it useful as a Data Science environment.

CTags

Activate CTags in Kate to efficiently browse and navigate through code. First, it has to be installed, on Ubuntu using:

$ sudo apt install exuberant-ctags

Activate the CTags plugin in Kate: Settings Configure Kate -> Plugins -> Click the Ctags button.

Define key bindings for CTags: Settings -> Configure Keyboard Shortcuts -> Action CTags. I use CTRL-Y for jumping to a function definition, CTRL-Q to go back, and CTRL-ALT-Q to go to a declaration. Note that code needs to be processed by CTags in order to navigate through code. This can be done using the CTags button at the bottom via “indexing files”. Remember to update the index when writing new code.

By default, CTags does not include support for the R language, which can however can be added by the user. To enable R support, we can add the following lines to a file “.ctags” in the home directory (if it does not exist, create it):

--langdef=R
--langmap=r:.R.r
--regex-R=/^[ \t]*"?([.A-Za-z][.A-Za-z0-9_]*)"?[ \t]*(<-|=)[ \t]function/\1/f,Functions/

Submit code to the console

For python, I use the ipython konsole, and for R, I use radian. Then, we have an “intelligent” console, while the editor itself is still rather “dumb”. For example, in RStudio or rkward the editor understands the R environment and may offer completion suggestions for function arguments. When using Kate, we do not have this convenience.

To submit code to the console via CRTL-Shift-C, add the following VI keybindings:

  • normal mode:
    • <s-c-c>: } V { y <f4> <s-c-v> <cr> <f4> <esc> }
  • insert mode:
    • <s-c-c>: <esc> } V { y <f4> <s-c-v> <cr> <f4> <esc> } i
  • visual mode:
    • <s-c-c>: y <f4> <s-c-v> <cr> <f4> <esc>

This way, CTRL-Shift-C will execute either the current (or following) code block or, when in visual mode, the code selection.

To send the entire document to the console via CTRL-Shift-Z, add this keybinding:

  • Normal mode:
    • <s-c-z>: mz ggVG y <f4> <s-c-v> <cr> <f4> <esc> `z<c-a-m>
  • Insert mode:
    • <s-c-z>: <esc> mz ggVG y <f4> <s-c-v> <cr> <f4> <esc> `z<c-a-m>i

Problems with R / radian in the Kate terminal

In the current version of Kate that I use, the konsole terminal does not play entirely flawlessly with R or radian; it has to be started using sudo radian and then, the user R library is not found, meaning that depending on how the R packages were installed, these cannot be found when using R in Kate. I expect that this problem will vanish in future releases. For now, I had to add a .radian_profile file that adds my user R library to the search path .libPaths().

Another option I use in my .radian_profile file is for changing the color mode:

options(radian.color_scheme = "colorful")

Otherwise the text in the console is not very readable on my machine.

Improved syntax highlighting for R code

The standard syntax highlighting scheme for R code ist rather old. Use my improved syntax highlighting, instead, which for example includes syntax highlighting for roxygen documentation in R packages. Get the syntax highlighting file here. and add it to

~/.local/share/katepart5/syntax

or

~/.local/share/org.kde.syntax-highlighting/syntax

Create these directories if they do not exist.

Optimizing indentation

In this section I will describe how to optimally use indentation in Kate, as soon as I understand it.

Last updated: 2020-11-19

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