band

Julia

struct Band
Band(rows::Vector{Tuple{Int64, Int64}}, ridx::Vector{Union{Int64, String}}, cidx::Vector{EarthSciAST.ASTExpr}, coef::EarthSciAST.ASTExpr, contracted::Vector{Tuple{String, Int64, Int64}})
Band(rows, ridx, cidx, coef, contracted)
Band(rows, ridx, cidx, coef)

Band

One structured block of ∂(rhs of the equation for u)/∂v:

• rows::Vector{Tuple{Int,Int}} — a rectangular region of u’s index space, per-dimension inclusive (lo, hi). Empty for a scalar u.
• ridx::Vector{Union{String,Int}} — per-dimension row index: a free index NAME ranging over rows[k], or a constant Int for a singleton dimension.
• cidx::Vector{ASTExpr} — v’s column index expressions, one per dimension of v, in terms of the row index names. Empty for scalar v.
• coef::ASTExpr — scalar ESM coefficient expression in terms of the row index names (plus parameters and other states).
• contracted::Vector{Tuple{String,Int,Int}} — free CONTRACTED column dimensions (name, lo, hi): when non-empty the band denotes, for every row cell AND every value of the contracted names over their inclusive ranges, an entry J[row, cidx(row, contracted…)] += coef(row, contracted…) — entries meeting at one column ACCUMULATE (this is how a reduce: "+" faq node’s sum over a gathered column materializes). Empty for ordinary bands.

The band is the symbolic, portable analogue of the tree-walk’s _AccDesc state-read descriptors: cidx of the form row ± const is an affine stencil offset, cidx == ridx is a diagonal (per-cell) coupling, and a cidx referencing a contracted name is an indirect/contracted gather (source–receptor matrices, regrid joins, conn[]-table stencils).

Source

Python

class Band
Band(rows: list[tuple[int, int]], ridx: list, cidx: list, coef: Expr, contracted: list[tuple[str, int, int]] = list())

One structured block of ∂(rhs of the equation for u)/∂v — see the Julia reference docstring and esm-jacobian-spec.md §4. contracted holds free contracted column dimensions (name, lo, hi).

Source

Rust

pub struct Band {
    pub rows: Vec<(i64, i64)>,
    pub ridx: Vec<RIdx>,
    pub cidx: Vec<Expr>,
    pub coef: Expr,
    pub contracted: Vec<(String, i64, i64)>,
}

One rectangular region of a Jacobian block: the rows it covers (rows, 1-based inclusive ranges, named by ridx), the column-index expressions (cidx) and the coefficient expression (coef). contracted lists extra column dimensions that accumulate (summed) at assembly.

Source · Rust docs