## Inkscape Extension ‘svg2tikz’ revisited.

In this earlier posting, I had written about the low-performing 3rd-party Inkscape Extension known as ‘svg2tikz’. Nevertheless, this extension may prove useful to some users, who wish to import an arbitrary document-type into Inkscape – preferably vector-based – and who wish to convert that into LaTeX in some way. And it seems that, even though this project was abandoned some time ago, work has slowly begun to resume on its source-code. And so, I should also fine-tune some of the earlier commentary I had made about this extension.

First off, there is an important detail about how to compile and install this extension, which its devs fail to point out anywhere. It needs to be built and installed, using Python 3, while many Linux computers still default to Python 2.7. Therefore, the commands to build and install it are:


$python3 setup.py build$ su
(...)
# python3 setup.py install



If one neglects this detail, then Unicode support is left out, and usually, SVG Files etc., will contain some Unicode characters. Further, as the Github comment states, while the importing of raster-based images is now supported, their import as Base-64 encoded, inline data is not. Therefore, within Inkscape, for example if a PDF File is being imported, the option needs to be unchecked, to ‘Embed’ graphics. And when Saving a Copy to TiKz Format, the option should also be unchecked, to ‘Indent Groups’.

But this last detail leads me to an important, additional observation. I have always known that the export of Text with the Figure has been dodgy. But lately, either because I’ve become more observant, or, because the behaviour of the latest version of the extension has improved, I’ve noticed what, exactly, goes wrong with Exporting Text along with the Figure.

(Updated 2/11/2020, 1h05 … )

## Testing the EPUB3 / MathML Support of the E-Book Reader

One subject which I wrote about before was, that while the MathML standard exists, as well as E-Book Readers capable of parsing at least a subset of the EPUB3 standard, most E-Book Readers that people can download and use fully, for free, under Android, fail to do so.

Specifically, I was disappointed that ‘FBReader’ fails to do so. OTOH, I had already written that ‘Infinity Reader’, an Android app that requires an in-app purchase to get rid of the advertisements, at least does support that part of the standard.

The following is a document, which the reader of this blog can use, to test this ability:

http://dirkmittler.homeip.net/MathML-Test_1.epub

(Update 1/31/2020, 20h05 … )

(As of 1/29/2020, 14h30 : )

On this blog, unless I really need to typeset Math perfectly, I’ve been using the EPUB2 posting-tag, and encoding Math to standard HTML, without any MathML. In case the reader did not know, an EPUB File is really a collection of HTML Files (in addition to other file-types one would find on a Web-site, as well as a manifest file), that have been Zipped. (:2) When I tell my software to output Math notation to this form of HTML, what it will often do is to generate PNG Image Files, and to flow those in-line with text. And the evil with that is, that an image flowed in that way, can be commanded by the HTML in question, or the CSS File (more probably), to align with the text, so that the text will be at the Top, in the Middle, or with the Bottom of the image. Why is that a problem? Because even though I have given the appropriate HTML directives in the past, the way some EPUB-capable E-Book Readers render it, ignores the specific instructions…

… (:1)

One step which I always take, is to preview the (main) HTML File using Firefox, before generating an EPUB File.

## An affirmation of a concept that exists in Calculus 2, the Integral of (1/x).

There are certain concepts in Calculus 2, which introduces definite and indefinite integrals, that are taught to College and University Students, and which are actually considered to be basic information in Higher Math. One of them is, that the integral of (1/x) is the natural logarithm of (x).

Yet, some people just like to go around and dispute such things, much as the concept is popular, that (2+2) does not equal (4). And so, what I have just done is to ignore the obvious fact, that people who studied Calculus at a much higher level than I have, have found an analytical proof, and to ask the question:

‘What would happen if the integrals of simple power functions were given, that have powers slightly more-negative and slightly more-positive than (-1), in relation to this accepted answer, the natural logarithm of (x)?’ The accepted answer should always fall between those two curves, even if some plausible arbitrary constant is added to each power-function integral, such as one which sets all the functions to equal zero, when the parameter equals one. Not only that, but it’s easy for me to plot some functions. And so, the following two worksheets have resulted:

Testing the Integral of (1/x) – EPUB File for Mobile Devices

Testing the Integral of (1/x) – PDF File for Desktop and Laptop Computers

Further, I’d just like to remind the reader, that a function can easily be defined that follows a continuous line, except at one parameter-value, at which it has a different value, such that the neighbouring intervals in the domain of said function do not include this endpoint, in either case. The only question which remains is, whether that function is a correct answer to a question. And, because such functions are possible, the answer depends on additional information, to the idea that there are exceptions to how this function is to be computed.

(Update 1/26/2020, 20h20 : )