R/134_constraints_cones.R

In CVXR: Disciplined Convex Optimization

#####
## DO NOT EDIT THIS FILE!! EDIT THE SOURCE INSTEAD: rsrc_tree/constraints/cones.R
#####

## CVXPY SOURCE: constraints/cones.py
## Cone -- base class for all conic constraints
##
## A thin subclass of Constraint that provides:
## - dual_cone() -- abstract, must be overridden by subclasses
## - dual_residual() -- computed from dual_cone + residual


Cone <- new_class("Cone", parent = Constraint, package = "CVXR")

# -- dual_cone: abstract on Cone ----------------------------------
## CVXPY SOURCE: cones.py lines 44-56 -- _dual_cone (raises NotImplementedError)

method(dual_cone, Cone) <- function(x, ...) {
  cli_abort("{.fn dual_cone} not implemented for {.cls {class(x)[[1L]]}}.")
}

# -- explicit-args guard shared by the dual_cone methods ----------
## R-SPECIFIC helper (no single CVXPY counterpart). Every CVXPY `_dual_cone(*args)`
## asserts, on the explicit-args branch, that the args match the constraint's own
## args in count and shape -- exponential.py:159-163, power.py:149-153 and
## :323-327, second_order.py:190-194. The two asserts are hoisted here once and
## raised with cli_abort(). Claims-audit row C0334, ported 1.9.2.9137.

.dual_cone_check_args <- function(x, args) {
  n <- length(x@args)
  if (length(args) != n) {
    cli_abort(
      "{.fn dual_cone} expects {n} arguments for {.cls {class(x)[[1L]]}}, got {length(args)}."
    )
  }
  same_shape <- mapply(
    function(a, b) identical(as.integer(.shape(a)), as.integer(.shape(b))),
    args, x@args
  )
  if (!all(same_shape)) {
    cli_abort(
      "{.fn dual_cone} arguments must have the shapes of the {.cls {class(x)[[1L]]}} arguments."
    )
  }
  invisible(TRUE)
}

# -- dual_residual ------------------------------------------------
## CVXPY SOURCE: cones.py lines 58-66 -- dual_residual property
## Calls _dual_cone with dual variables, then returns residual of that cone.

method(dual_residual, Cone) <- function(x) {
  dc <- do.call(dual_cone, c(list(x), x@dual_variables))
  residual(dc)
}

# -- print --------------------------------------------------------

method(print, Cone) <- function(x, ...) {
  cat(expr_name(x), "\n")
  invisible(x)
}