# TeXmacs: Thermodynamics and Chemistry by Howard DeVoe - done

Created by Steven Baltakatei Sandoval on 2022-03-17T02:21Z under a CC BY-SA 4.0 license and last updated on 2022-03-20T18:18Z.

## Summary

Thermodynamics and Chemistry by Howard DeVoe, Version 10, Transcribed to TeXmacs. It's done. See the repository for the source code. Compare to the original compiled from LaTeX here.

This past week I've made an effort to finish off the Bibliography and citations of the thermodynamics textbook transcription job I assigned myself over a year ago.

## Bibliography wrangling

I had to figure out how exactly TeXmacs processes bibtex data. It's complicated and usage isn't well-documented but I found a way that works (when inserting an automatically-updating bibliography section via "Insert -> Automatic -> Bibliography", it is possible to specify a file as well as a bibliography style if you examine the <bibliography> tag that is created; the file must be a bibtex file; then, a tag like <cite|author-1999> will trigger the bibliography section to read the file and populate itself with a new bibliography entry and assign the <cite> tag a reference number).

One of DeVoe's bibtex entries kept causing crashes in TeXmacs whenever I tried to update the bibliography. It was the only one of its kind.

@incollection{
clapeyron-1834,
Author = {Clapeyron, \'{E}.},
Title = {Memoir on the Motive Power of Heat},
BookTitle = {Reflections on the Motive Power of Fire: Sadi Carnot and other Papers on the Second Law of Thermodynamics by \'{E}.\ Clapeyron and R.\ Clausius},
Editor = {Mendoza, E.},
Publisher = {Dover},
Address = {Mineola, New York},
Pages = {71-105},
Note = {Translation by E.\ Mendoza of M\'{e}moire sur la Puissance Motrice de la Chaleur,'' \emph{J.\ de l'\'{E}cole Polytechnique}, \textbf {14}, 153--190 (1834).},
Year = {1988} }


The problem is with the Note value. There's a lot of what looks like LaTeX code (which I'm not familiar with). I'm using the tm-plain style which seems to be okay with processing some LaTeX'isms in these bibliographical entries (a lot of the markup seems to be used to effect diacritical marks which could be handled by use of UTF-8 characters, but I wasn't about to go down the rabbit hole of figuring out how TeXmacs handles Unicode points in its bibliography processing code). I switched out the Note value to something simpler (that references the title's OCLC code) and now book.tm compiles (clapeyron-1834 was used in a citation in bio-CLAPEYRON.tm).

Note = {See OCLC 559435201; 153--190.},


## Two columns in one column document

I also figured out that its possible to get two-column pages in an otherwise single-column TeXmacs document. Basically, you create a two-column page (single page only) in one TeXmacs document (.tm) then <include> it in another document (via "Insert -> Link -> Include"). I'm pretty sure this is stretching what the original developer intended but it seems to work well enough for the single-page biographical sketches that DeVoe included in his book.

## Disappearing Dotted Line

A few months into the transcription project, I emailed Howard DeVoe a PDF of a draft. He noted that some figures had dashed lines that changed depending on how far you were zoomed in. Eventually I concluded the cause of that problem was some error / wrong assumption made by either Inkscape, ghostscript, or some converter in between the source Encapsulated Post Script (EPS or .eps) file that DeVoe had emailed me and the .eps file that I got to work when inserted into the TeXmacs documents. Instead of trying to hunt down the cause, I decided to try and fix each issue in each .svg file that Inkscape could produce from each .eps file.

SVG is an XML-like format that I can easily parse with grep, sed, and other command line tools that I'm familiar with; in contrast, EPS is compiled output not meant for direct editing (perhaps decades ago it was meant to be human-editable but SVG seems to be the standard now). So, I converted every EPS file I received from DeVoe into an SVG master file from which I would export EPS or whatever format I needed to make the book work (see ink_export_to_eps.sh). I found that each image with the dynamically chnanging dashed line issue also had a "stroke-dasharray" key value pair; so, I wrote ink_convert_dash.sh (in ref/notes/baltakatei/bash/ in the repository), a script to convert each dashed path object into a path object in which each dash is a subpath; it greatly increases the amount of information requried to define the dashed line but the benefit is that the dashed line appears the same no matter the zoom level; in other words, every single dash is converted into a static object instead of letting whatever vector renderer decide how to draw a dashed line.

While I was patting myself on the back for figuring out how to automatically get Inkscape to process the many SVG files I had, I noticed that some of the images lost some dotted lines. I eventually discovered that some dashed lines had dashes with dash lengths specified so short (zero length), that the Inkscape extension I was using (org.inkscape.filter.dashit.noprefs) was encountering a "divide by zero" error and deleting the path partially or entirely.

Soooooo, I had to write ink_stroke-dasharray_zerofix.sh to run before I ran ink_convert_dash.sh. ink_stroke-dasharray_zerofix.sh would change all the 0's in each stroke-dasharray to something small. I also filed a bug report (which led to a fix that was merged by a Jonathan Neuhauser; thanks!). Testing showed me that a value too close to zero would be the same as if zero were still present. I had to use a relative value of nearby non-zero values in the stroke-dasharray and my code is super brittle (it probably wouldn't work for all dashed paths encoding all possible morse code sequences, but my problem was just with simple dotted lines disappearing). … — …

I debugged the scripts so they'd do what I wanted (fix the dashed paths into paths with static subpaths for each dash/dot). I definitely couldn't do what I did with earlier versions of Inkscape; I downloaded and ran the latest Inkscape version (inkscape 1.2); its command line interface is super slick (although it would be nice if there were a sleep command to let me get a peek at changes).

Long story short, I think I've resolved the dashed line issue, Professor DeVoe. ^^;;

## Next steps

The core reason I transcribed the textbook in the first place was so that when I completed the problem sets for my own review and education, I'd be able to have a digital document that I could link to and share with others. That means the next step, now that transcription is done, is to create my own solutions to the problem sets and record them in TeXmacs.

This means I will probably need to use DWSIM more in order to cross-check my thermodynamic calculations and create illustrations / diagrams relevant to each solution. Again, I want to be able to hand someone a ZIP file containing everything they need to learn Chemical Engineering; that means not only textbooks and problem sets, but also simulation software that they might use when applying this knowledge in industry. A ZIP file that I could in good conscience send to the people on the ISS should everyone on the planet's surface be doomed.