Ternary Contour Plots in JavaScript

I would like to reopen #3503.

Currently there is no native support of ploting contours in ternary plot, the current official documentation for it is wrong (or inconsistent). As reported in this issue from the graphing-library-docs repo.

In plotly.py, Ternary contours in Python, there are ternary contour plots examples:

But in JS, Contour Plots in JavaScript, we only get:

Apparently, the JS example only fills the area instead of doing what is expected of a "contour" plot.

It would be great if this could be implemented (or if it already is, but only requires data transformation? ) and if there were examples showing how to plot the contours as in Ternary contours in Python.

Commencez par la documentation liée sur JavaScript ternary-contour et contour-plots, puis comparez-la aux exemples liés de Python ternary-contour. Déterminez si Plotly.js prend déjà en charge le rendu demandé ou si une implémentation et des exemples sont nécessaires ; le travail est terminé lorsque JavaScript peut produire des lignes de contour comparables à celles des exemples Python et que la documentation officielle est correcte.