render Rmd files

Keep this code in the Rmd

# ---- Setup for unique image handling ----

# Define a unique prefix for this post (match your .md filename)
post_prefix <- "2025-11-22-topics-use-case-PL-"

# Configure knitr chunk options
knitr::opts_chunk$set(
  fig.path = paste0("images/", post_prefix),  # save plots into root/images/
  fig.ext  = "png",
  fig.align = "center"
)

# Custom hook: replace default ![] markdown with <img src="...">
knitr::knit_hooks$set(plot = function(x, options) {
  raw_url <- paste0(
    "https://raw.githubusercontent.com/vladdsm/myblog_attempt/master/",
    x
  )
  sprintf('<img src="%s" alt="plot" />', raw_url)
})

Instructions to running this website

Source: arkadianriver.com: based off the http://html5up.net/spectral design by @ajlkn. The site is made for blog and portfolio content. The blog can contain both personal entries and entries by syndicated authors. The site uses jekyll, a method of creating and maintaining a web site, which works by using local templates to generate static files that you upload and sync with your remote site. This repo is the same code I use for my site, excluding my posts.

If you clone or fork this repo to use it:

0. Install Jekyll (version 3.1.2 or higher). DONE

1. Tweak the site to make it your own. Jekyll uses YAML files for its site variables:

   a. Edit the _config.yml file, replacing the values for each key with your info. DONE (seems to be)

   b. Add a _data/tokens.yml file with your IDs & mail program. Not clear See the _data/tokens-template.yml. file for example entries.

   c. Add author info for yourself in _data/authors.yml as the first author entry in the file.

   d. Provide your own images.

   e. Continue tweaking to your heart's desire, or not.

2. Create your posts:

   a. Use the posts in the 31st century as guides for yours. They're built by jekyll only when the --future option is used. Where should I add this option?

   b. You can run ruby compose.rb to create new draft posts.

3. Test and publish your site:

   If you're building your site on Windows (like me) and you use WinSCP to sync with your remote site, you can use the site.bat file. Set up a _site.env file as described in the comments of site.bat and change the excludes list for your site.

   site dev runs jekyll serve --future --drafts in development mode.
   site devnof runs jekyll serve --drafts in development mode.
   site preview runs jekyll serve in production mode.
   site prod simply builds with jekyll build in production mode (no serve).
   site publish uses WinSCP's synchronize feature to mirror to a remote site.

Adding info from Templates - rules to build posts

---

title: Guide for new posts categories: topics excerpt: Front-matter guide for site pages and posts

Required

categories

If it's a post, the categories array is required with at least the first element set to the permalink name of its parent page (so that breadcrumbs work).

{% highlight yaml %} categories: topics ... {% endhighlight %}

The two top-level categories with provided index pages are topics and works.

If you want back/next navigation within a subcategory:

{:.nobullet}

• Create a first post for the sub-category, but with a permalink. The category list can be space-delimited on one line or in a bulleted list. Note that the category names must exactly match the permalink.

  {% highlight yaml %} categories: topics my-great-vacation permalink: /topics/my-great-vacation/ {% endhighlight %}

{:.nobullet}

• The site permalink would be: /topics/my-great-vacation/index.html

{:.nobullet}

• If your subcategory contains spaces, specify categories as an array

  {% highlight yaml %} categories:

  • topics
  • my great vacation permalink: /topics/my great vacation/ {% endhighlight %}

{:.nobullet}

• For subsequent topics in the sub-category, add the sub-category and no permalink:

  {% highlight yaml %} categories: topics my-great-vacation {% endhighlight %}

{:.nobullet}

• resulting in: /topics/my-great-vacation/topic-title.html

{:.nobullet}

• Topics in the sub-category are sorted by date (and time). Therefore, if they all fall on the same day, specify the date in the post with a timestamp by which to sort.

  {% highlight yaml %} date: 3009-09-22 00:00:03 {% endhighlight %}

excerpt

You'll probably wanna provide an excerpt in front-matter, because relying on jekyll to get the excerpt from the body has too many caveats. The excerpt is truncated as necessary in references, so it can be as long as you want, except that it's also displayed, centered, right under the topic title (in all caps).

{% highlight yaml %} excerpt: yada yada {% endhighlight %}

permalink

If it's the first page of a sub-category, use a permalink for the categories. It becomes the index that a breadcrumb link would pop up to, ie: /topics/new-category/index.html. Also see categories.

{% highlight yaml %} permalink: /topics/new-category/ {% endhighlight %}

title

Title for <title/> and <h1/>. For this and all other fields refer to Yaml restrictions on when you need to quote the value.

{% highlight yaml %} title: My interesting topic {% endhighlight %}

Presentation options

author

If you want the article to be attributed to an author, specify a name that corresponds to a key in the _data\authors.yml file.

{% highlight yaml %} author: key_name {% endhighlight %}

background-image

If you want a larger title block with a background image, specify it here. If it's in the /images/ folder, specify just the name; otherwise specify the folder relative to your jekyll root, starting with /. If it's a remote image, begin the name with //. Use a high resolution image, if possible, for when viewed full screen. Once displayed, you'll wanna slowly resize your browser or use its developer tools to see how the image responds for all @media breakpoints and crop it as necessary.

{% highlight yaml %} background-image: imagefile.png {% endhighlight %}

icon

For the featured articles on the main page, if you want an icon other than the heart icon, specify the font-awesome icon identifier (just the text after fa-). See the [font-awesome icons]({{ '/topics/icons.html' | prepend: site.baseurl }}) topic for a list of available icons.

{% highlight yaml %} icon: industry {% endhighlight %}

layout

For both posts and pages, there's no need to specify the layout. Specifying the layout is optional because defaults are set in the _config.yml file to set the layout based on the folder it's in (_posts or _pages). The layout is useful for pages outside of these folders, however.

{% highlight yaml %} layout: {page|post} {% endhighlight %}

options

The options allow you to customize the page somewhat.

{% highlight yaml %} options:

• minihead # as minimal a title as possible, and no date printed
• fullwidth # leaving only a tiny margin on all media sizes
• nocomment # disable disqus comments for this post
• nomenu # for pages, don't add to the menu
• nolanding # for pages and featured posts, don't add to the landing page {% endhighlight %}

Note that disqus comments are not displayed on works posts.

Ordering and site map options

changefreq

The default change frequency for all pages in the site map is monthly. Depending on how often you think you'll edit a page, you can set the page change frequency. Here's a good guide on when to use the available values.

{% highlight yaml %} changefreq: weekly {% endhighlight %}

key

All files in the _pages folder are displayed in the nav menu unless you set the nomenu option. Use key to specify the order you want the pages listed in the nav menu. Values are sorted in ascending order.

{% highlight yaml %} key: 2 {% endhighlight %}

lastmod, date

If you want the site map lastmod setting to be updated, you can set one or both of these to your new modified date as YYYY-MM-DD HH:MM:SS +/-TTTT (lastmod has priority). If you use date, the date shown on the page is also modified, overriding the date in the filename. The timestamp is assumed to be UTC unless you specify the time zone offset afterward.

{% highlight yaml %} lastmod: 2016-03-13 23:11:00 date: 2016-01-01 00:00:00 -0800 {% endhighlight %}

priority

Use priority to specify two things:

• the grouping in the works index
• the site map priority

{% highlight yaml %} priority: 0.8 {% endhighlight %}

In the works index, the works are grouped by priority, listed by descending priority and by descending date within each priority.

Note: For now, works posts must have a priority set for the ordering to work. If you get a "can't compare float with nil" error in your jekyll build, there's a missing priority somewhere.

Because the value is used to set the site map priority, it must be set to a value between 0 and 1.0. I have three groups of works, using priorities 0.7, 0.6, and 0.5. None as high as featured posts, but then, I'm not looking for a job right now. ;-)

Default priorities in the sitemap.xml file:

• 1.0 - Landing page
• 0.9 - Featured posts
• 0.7 - Other posts
• 0.5 - Pages

sitemap_exclude

Set to yes if you want to exclude a page from the sitemap.

{% highlight yaml %} sitemap_exclude: yes {% endhighlight %}

tags

For topics posts, the only tag that has an effect right now is featured, which adds it to the top of the /topics/ page. The most recent eight featured posts are also added to the main landing page.

{% highlight yaml %} tags: featured {% endhighlight %}

For works posts, the tags become a listing of skills demonstrated. For example:

{% highlight yaml %} tags:

• C
• Windows DLL
• SGML {% endhighlight %}


You can add the featured tag to a work if you want it to appear on the main landing page. The featured tag is excluded from the list of skills on the page and works index. However, its page priority overrides the standard priority of featured posts in the site map.

CSS and Script support

includes

If your page needs to include stylesheets or scripts, provide 'em as either local or remote URLs. Prefix remote urls with //, not http. Stylesheets are included in the header and scripts at the bottom before the body closes.

{% highlight yaml %} style-includes:

• /local/path/to/stylesheet.css
• //remote.com/url/to/stylesheet.css {% endhighlight %}

{% highlight yaml %} script-includes:

• /local/path/to/script.js
• //remote.com/url/to/script.js {% endhighlight %}

style, script

These are useful when you want to embed styles and scripts outside of the {% raw %}{{ content }}{% endraw %} area. Use the yaml | indented block to ensure line breaks are preserved. The styles are included in the header below stylesheet includes; scripts are included at the bottom below script includes.

{% highlight yaml %} style: | /* some css block here */ .some-class { somestyle: definition; } {% endhighlight %}

{% highlight yaml %} script: | // some script block here... $(document).ready(function(){ ... }); {% endhighlight %}