# Articles by Stéphane Laurent

### Child tables with DT, editing, exporting

May 7, 2020 |

I’m going to show how to use the DT package to do a table with child tables, and how to edit and export such a table. In order to do a table with child tables, one adds a list column to the ... [Read more...]

### Focal quadrics and their lines of curvature

May 2, 2020 |

This blog post provides some R code for drawing focal quadrics and their curvatures lines with the rgl package. Ellipsoid The ellipsoidMesh function below generates a mesh of the ellip... [Read more...]

### Drawing slices of a hypersurface with R

April 30, 2020 |

Let $$s \colon I \times J \times K \to \mathbb{R}^4$$ be a parameterization of a hypersurface $$\mathcal{S}$$, where $$I,J,K \subset \mathbb{R}$$ are some intervals. I’m going to show how ... [Read more...]

April 11, 2020 |

### The Beta distribution of the third kind (or generalised Beta prime)

July 21, 2019 |

Preliminaries: the (scaled) Beta prime distribution Beta distribution of the third kind Update 2019-09-05: generalised Beta distribution ... [Read more...]

### Drawing nested Steiner chains

July 12, 2019 |

This is a Steiner chain with its enveloping cyclide: And these are nested Steiner chains: With R We will include the cyclides in the plot. We firstly write a functi... [Read more...]

### Plotting the columns of a Datatable

July 9, 2019 |

Here is the code of this app: library(shiny) library(shinyBS) library(DT) library(ggplot2) ui [Read more...]

### Useful callbacks for DT (in Shiny)

June 13, 2019 |

Edit cells on pressing Tab and arrow keys Select rows on click and drag Getting the selected rows Edit columns... [Read more...]

### Drawing hyperbolic polyhedra

April 4, 2019 |

A. A. Ungar has developed the concept of gyrovector space. His theory provides a (gyro)vector approach to hyperbolic geometry. Ungar deeply studied three examples of gyrovector spaces; they ... [Read more...]

March 12, 2019 |

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