Margins and joint distributions

Toolset copula_distribution: 2 tools.

Tool	What it does	Notes
`copula_joint_density`	Fits a joint distribution of several assets on the original scale: each margin a kernel density (default; continuous, discrete or zero-inflated, with optional bounds) or the best parametric family, then a vine copula on the margins’ probability transforms.
`copula_margin_fit`	Fits one variable’s marginal distribution: a boundary-corrected kernel density (continuous, discrete or zero-inflated, default), the best parametric family among normal, Student t, Laplace, skew-normal and others by AIC/BIC/AICc (or one family with given or partly fixed parameters), or a density supplied on a grid.

Inputs, limits and outputs are described in Fincept Copula. Full schemas: fincept_describe_tool.