Sekai 🌐 🗺

Sekai is the kanji for 世界, meaning “the world”. That’s a great word because of the scale it designates.

Finite Population Sampling without Replacement

Personal note of finite population sampling

First moment Population: \( \Omega = \{ x_1, \dots, x_N \} \) Collection of $n$-samples: \(\mathcal{S} = \{ s \in \Omega^n \mid \forall i,j \in s, i \ne j \} \) Collection of $n$-samples containing $x$: \( \mathcal{S}_x = \{ s \in \mathcal{S} \mid x \in s \} \) Observe that \( |\mathcal{S}_x| = \binom{N-1}{n-1} \). Let population mean be zero. $\mu = 0$, i.e. \( \sum_{i = 1}^N x_i = 0 \) [Read More]

Replacing Deprecated Hugo Syntax in Blog Theme

Fixing Beautiful Hugo issue #261

Problem Since the recent Hugo upgrade to v0.55.3, the following messages popped up after each local site regeneration with hugo server. WARN 2019/04/24 18:07:00 Page's .URL is deprecated and will be removed in a futu re release. Use .Permalink or .RelPermalink. If what you want is the front matte r URL value, use .Params.url. WARN 2019/04/24 18:07:00 Page's .Hugo is deprecated and will be removed in a fut ure release. [Read More]

Julia Rcall Installation

Rcall.jl build failure due to missing dependencies

Problem During the installation of RCall.jl, the package wasn’t successfully built due to a missing variable $R_HOME. $ julia -q julia> Pkg.add("RCall") Resolving package versions... Installed WinReg ─ v0.3.1 Installed RCall ── v0.13.2 Updating `~/.julia/environments/v1.0/Project.toml` [6f49c342] + RCall v0.13.2 Updating `~/.julia/environments/v1.0/Manifest.toml` [6f49c342] + RCall v0.13.2 [1b915085] + WinReg v0.3.1 Building RCall → `~/.julia/packages/RCall/ffM0W/deps/build.log` ┌ Error: Error building `RCall`: │ ERROR: LoadError: R_HOME is not a directory. │ Stacktrace: │ [1] error(::String) at . [Read More]
Julia  RCall  R 

Xubuntu Screen Enlargement

Tonight, the screen of Xubuntu suddenly enlarged and blurred. Typing “xubuntu screen display enlarged” on Google, I’ve learnt that the <Alt> key and the mouse scroll wheel can enlarge/minify screen display from Ubuntu Forums.


Cantonese vs Mandarin for Reading Tang Poems

Comparison using Du Mu's poem

This is a linkblog to a post on Discuss HK which claims how Mandarin (普通話) messes up the flat and oblique tones (平仄) of the regulate verse (近體詩) below. 《山行》 杜牧 遠上寒山石徑斜,白雲生處有人家。 停車坐愛楓林晚,霜葉紅於二月花。 Cantonese (粵語) Mandarin (普通話) 仄仄平平仄仄平 仄平平仄仄平平 平平仄仄平平仄 仄仄平平仄仄平 仄仄平平平仄平 平平平仄仄平平 平平仄仄平平仄 仄仄平平仄仄平 However, Kimery has checked the Mandarin pinyin (拼音) and (s)he doesn’t found such problem except for some characters with entering tone (入聲). [Read More]

Quels schémas à tester ?

Pour simuler les trajectoires d'une équation différentielle, le schéma le plus facile est l'un découvert par Euler. Cependant, en espérant mettre ce que j'ai vu au cours de ma licence en pratique, j'ai cherché un peu sur des méthodes numériques pour les EDS sur Google, et je suis tombé sur un article écrit par Brian D. Ewald. Les différences entre les schémas « forts » et « faibles » seraient-ils pertinents pour mon stage ? [Read More]

Borel Cantelli Exercise 2019

I intend to post this for a Borel-Cantelli lemma exercise on Math.SE.

The target event is ${\exists i_0 \in \Bbb{N} : \forall i \ge i_0, X_i = 1}$, whose complement is

\[ \{\forall i_0 \in \Bbb{N} : \exists i \ge i_0, X_i > = 0\} = \limsup_i \{X_i = 0\}. \]

To apply Borel-Cantelli, one has to determine whether $\sum_i P(X_i = 0)<+\infty$.

Mise à jour du template de lettre

Template de lettre en Xe$\LaTeX$

Contexte J’ai publié mon template de lettre en Xe$\LaTeX$ sur mon ancien blog (hébergé sur GitHub Pages) il y a trois ans. Problème et solution Après le changement de l’ordi portable, il me faut l’installation du pacquetage “texlive-lang-french” sur la nouvelle version d’Ubuntu. Sinon, une erreur du pacquetage Babel se surviendra. ! Package babel Error: Unknown option `frenchb'. Either you misspelled it (babel) or the language definition file frenchb.ldf was not foun d. [Read More]

Staticman Failure on Tsalikis' Site

Use Alternative Staticman API server

After reading Hugo Comments with Staticman on Kostas Tsalikis’ web site, I tried to leave the following comment. As far as I know, Staticman can be used only with GitHub, since it works as a GitHub bot. Obviously, not all static sites are saved in GitHub, and this may be a showstopper for someone using another service. Thanks to eduardoboucas/staticman#219, Staticman now supports GitLab. You may view my demo Hugo site on Framagit at https://staticman-gitlab-pages. [Read More]