Category: LaTeX Notes & MathJax in Jekyll
I take Math of Cryptography and Machine Learning this semester. So I guess it is important for me to be able to input mathematics formular in blog posts when I want to write somthing about math.
TeX will also be awesome when I write some post in Physics category.
TeX is a text complier which produce high-quality formatted document on its own syntax. There are many software based on Tex. A well-know of them is LaTeX.
MathJax is a TeX tool purely based on javascript.
Notes for LaTeX
Here are some notes when learning Tex syntax.
Mrs. Krummel’s LaTeX Tutorials
Online LaTeX Equation Editor
\documentclass{article}
\begin{document}
math formular $A=x^2+4x+3$
spearate math formular $$A=x^2+4x+3$$
superscripts: $$2x^{34}$$ ==> x power 34
subscripts: $$x_1$$ $${{x_1}_2}_3$$
greek letters: $$\pi$$ $$\alpha$$ $$A=\pi r^2$$
trig functions: $$y=\sin{x}$$
log functions: $$\log_5{x}$$ $\ln{x}$
square roots: $$\sprt{2}$$ $$\sprt[3]{x^2+y^2}$$ $$\sport{1+\sprt{x}}$$
fractions: 2/3 == $$2/3$$ ==> 2/3
$$\frac{2}{3}$$ ==> 2upstair 3downstair
$\displaystyle\frac{2}{3}$ ==> enlarge the upper formular to better display
$$\sprt{\frac{x}{x^2+x+1}}$$
$$\{a,b,c\}$$ ==> {a,b,c}
$$\$12.55$$
$3\left(\frac{2}{5}\right)$
$$\left|\frac{x}{x+1}\right|$$
$$\left\{$x^2\right.$$ ==> {x^2
$$\left| \frac{dy}{dx} \right|_{x=1}$$ ==> |dy/dx|_x=1
\begin{tabular}{cccccc}
$x$ & 1 & 2 & 3 & 4 & 5 \\ \hline x 1 2 3 4 5
$f(x)$ & 10 & 11 & 12 & 13 & 14 \\ \hline ==> f(x) 10 11 12 13 14
\end{tabular}
\begin{eqnarray} ==> 右侧对其，每行末尾有(1)(2)等行号
5x^2-9=x+3\\ 所有的等号上下对齐
4x^2=12\\
x^3=3\\
x\approx\pm1.732 x 约等于 +-1.732
\end{eqnarray}
\end{document}
MathJax Guide
Simple guide for enabling MathJax.js on your Jekyll posts.
###1. Reference MathJax Library
<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
Using MathJax in popular web platforms
###2. Add MathJax Config Before the Reference
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
tex2jax: {
skipTags: ['script', 'noscript', 'style', 'textarea', 'pre']
}
});
MathJax.Hub.Queue(function() {
// Fix <code> tags after MathJax finishes running. This is a
// hack to overcome a shortcoming of Markdown. Discussion at
// https://github.com/mojombo/jekyll/issues/199
var all = MathJax.Hub.getAllJax(), i;
for(i = 0; i < all.length; i += 1) {
all[i].SourceElement().parentNode.className += ' has-jax';
}
});
</script>
We do this cause Markdown messes up MathJax!
Official guide: Using in-line configuration options
Or be guided from other bloggers: LaTeX Math Magic
###3. Custom the CSS
Of course, the CSS of your formular text can be redefined:
code.has-jax {font: inherit; font-size: 100%; background: inherit; border: inherit;}
###4. Try Your Own Formulars
Two approaches to insert your formulars in posts source file:
You could use: [](raw: put latex here) But this only works partly.
The markdown will interpret the first ) as the closing tag for our raw-statement.
Another approach is to use code blocks. So either using at least 4 spaces before you write something, or using the acute symbol: `. Inside the acute symol, brace the formular with \ [...\ ], you will write formular in a seperate new line, brace with \ (...\ ), you write formular inline.
In case you can not figure out the true html source code of formulars, just take a glance at cowoebker’s_post_source_code.
Some formulars you can test with: TeX Samples
example:
- Maxwell’s Equations
\begin{aligned}
\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \\ \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \\
\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \\
\nabla \cdot \vec{\mathbf{B}} & = 0 \end{aligned}
- Binomial Formular
The probability of getting \( k \) heads when flipping \( n \) coins.
\[
P(E) = {n \choose k} p^k (1-p)^{ n-k}
\]
- Kinetic Energy Equation
Kinetic energy of rigid bodies: \[ E_k = \frac{1}{2}mv^2 \]
Rotating bodies: \[ E_r = \frac{1}{2}Iw^2 \]
Cool.
###5. Tips
Avoid formatting text in formular by using \text tag: \[ IDF_t (Inverse Document Frequency) = \log( \frac {\text{Corpus size}} {\text{Document count contains term }t +1)} ) \] See the difference between text left to = and right to, where the right side is using \text tag.
Align = for multiline equations by using \( \text{\begin{eqnarray} ... \end{eqnarray}} \) and set the align mark with & = &: \[ \begin{eqnarray}\text{Simple TF}_t & = & \frac {f_{t,d}} {Max(f_{i,d})} \\
\text{Modified TF}_t & = & \log{|Sf_t - Hf_t |} \\
\text{Re-modified TF}_t & = & \frac {\log{|Sf_t - Hf_t |}} {Max(f_{i,d})} \end{eqnarray}\]
References:
Author: Doswa
Title: mathjax in markdown
Link: http://doswa.com/2011/07/20/mathjax-in-markdown.html
Author: Cecil Woebker
Title: LaTeX Math Magic
Link: http://cwoebker.com/posts/latex-math-magic/
Author: Krummel
Title: LaTeX Tutorials
Link: http://mrskrummel.com/latex/
Title: MATHJAX GUIDE: Math symbols and math fonts
Link: http://www.martinkeefe.com/math/mathjax3
Title: Math symbols and math fonts Link: http://www.martinkeefe.com/math/mathjax3
