Ulysses’ trip

Latest post

Mar 2, 2026, 00:07:43

I am using #Thunar as my #filemanager and #Ghostty as my #terminal. One thing that bugs me is that clicking "open terminal here" in Thunar opens Ghostty in the default working directory instead. I just fixed this today by changing the command to `TERM_PROGRAM=dumb exo-open --working-directory %f --launch TerminalEmulator`, i.e., adding an environment variable `TERM_PROGRAM`. The value does not matter, but it has to have some value for exo-open to work. No idea why.

Articles

Apr 12, 2020
The concentration change of gas in reversible reactions
A reversible elementary reaction takes place inside a closed, highly thermally conductive container of constant volume, whose reactants are all gases. Given the reaction equations and the reaction rate constants, a natural question to ask is how the concentration of each gas changes w.r.t. time. In this article, I will answer this question by proposing a general approach to solve it.
/chemistry #calculus #ode #chemical reaction #long paper
Apr 11, 2020
Snippet: O, ’tis too true!
O, ’tis too true!
/literature #snippet #chinese
Apr 8, 2020
The structure of a basic RM game
In this article, I present minimal examples of a RM game. They only illustrate the basic concepts of how a RM game is structured and what is the running logic of it.
/programming #ruby #javascript #rgss
Mar 27, 2020
The frequency assignment of musical notes
This article explores the concept which I call the frequency assignment, which is a mapping from $N$ (the set of notes) to $\mathbb R^+$ (the set of frequencies). Concepts such as octaves, intervals, and equal temperaments are introduced.
/music #music theory #number sequence #long paper #abstract algebra
Mar 3, 2020
Normal vectors of a scalar field
This article gives the formula for the normal vectors of a surface defined by a scalar field on $\mathbb R^n$ . The normal vector of the graph of the function $y=f\!\left(\mathbf x\right)$ at $\left(\mathbf x_0,f\!\left(\mathbf x_0\right)\right)$ is $\left(\nabla f\!\left(\mathbf x_0\right),-1\right)$ . This also provides us a way to recover a scalar field from the normal vectors of its graph: normalizing the vectors so that the last component is $-1$ , and then integrate the rest components.
/math #calculus #vector analysis
Feb 29, 2020
It is Feb 29 today!
It is Feb 29 today. The date appears once for as long as 4 years!
/update #fooling around
Feb 9, 2020
Monkey-patching graciously
Monkey-patching is a powerful tool in programming. In this article, I used techniques of Ruby metaprogramming to define a series of methods def_after, def_before, etc. to help monkey-patching. They look graciously in that we can use it to shorten the codes for monkey-patching (avoiding aliasing and repeating codes).
/programming #ruby #meta programming #long paper
Jan 26, 2020
Amazing Siteleaf
I have been using Siteleaf to manage my blog. It is just convenient and amazing.
/update #update #jekyll
Jan 25, 2020
Hyperellipsoids in barycentric coordinates
In this article, I introduce the barycentric coordinates: it is an elegant way to represent geometric shapes related to a simplex. By using it, given a simplex, we can construct a hyperellipsoid with the properties: its surface passes every vertex of the simplex, and its tangent hyperplane at each vertex is parallel to the hyperplane containing all other vertices.
/math #linear algebra #long paper
Jan 6, 2020
Use complex numbers as canonical variables
In this article, I try exploring an idea: using complex numbers to combine pairs of canonical variables into complex variables: $\mathbf c\coloneqq\alpha\mathbf q+\mathrm i\beta\mathbf p$ . It turns out that we can write canonical equations $\frac{\mathrm d\mathbf c}{\mathrm dt}=-2\mathrm i\alpha\beta\frac{\partial\mathcal H}{\partial\mathbf c^*}$ , Poisson brackets $\left\{f,g\right\}=-2\mathrm i\alpha\beta \left(\frac{\partial f}{\partial\mathbf c}\cdot \frac{\partial g}{\partial\mathbf c^*}- \frac{\partial f}{\partial\mathbf c^*}\cdot \frac{\partial g}{\partial\mathbf c}\right)$ , and canonical transformations $\frac{\partial\mathbf c^*}{\partial\mathbf c'^*}= \frac{\partial\mathbf c'}{\partial\mathbf c}, \frac{\partial\mathbf c}{\partial\mathbf c'^*}= -\frac{\partial\mathbf c'}{\partial\mathbf c^*}$ in these complex numbers. Finally, I show two examples of using them in real problems: a free particle, and a harmonic oscillator.
/physics #classical mechanics #canonical transformation #hamiltonian #complex #long paper