Filter Rows Of A PTTF Operator

Creates a new "pttf_operator" object with a subset of compact operator rows. The sparse triplet payload is rebuilt from the filtered matrix so triplet row indices always refer to the filtered fit rows, while original compact and full logical row identities remain in row.table.

Usage

pttf.operator.filter.rows(
  operator,
  rows,
  reason = NULL,
  preserve.original = TRUE
)

Arguments

operator

A "pttf_operator" object from pttf.operator.

rows

Integer, logical, or character row selector. Character selectors are matched against row.table$status.

reason

Optional character reason stored in row.filter.

preserve.original

Logical. If TRUE, preserve original row identities in row.table$compact.row and row.table$full.row.

Value

A filtered "pttf_operator" object.

Examples

n <- 10L
X <- matrix(seq(0, 1, length.out = n), ncol = 1)
adj <- lapply(seq_len(n), function(i) intersect(c(i - 1L, i + 1L), 1:n))
lengths <- Map(function(i, j) abs(X[j, 1] - X[i, 1]), seq_len(n), adj)
geometry <- pttf.geometry(
  X, adj, lengths, graph = "supplied", tangent.dim = 1L
)
operator <- pttf.operator(geometry, derivative.order = 2L)
pttf.operator.filter.rows(operator, seq_len(max(1L, nrow(operator$A) - 2L)))
#> PTTF transported-difference operator
#>   derivative order: 2 
#>   A dim: 8 x 10