R/211_reductions_dgp2dcp_canonicalizers_quad_over_lin_canon.R

In CVXR: Disciplined Convex Optimization

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## DO NOT EDIT THIS FILE!! EDIT THE SOURCE INSTEAD: rsrc_tree/reductions/dgp2dcp/canonicalizers/quad_over_lin_canon.R
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## CVXPY SOURCE: reductions/dgp2dcp/canonicalizers/quad_over_lin_canon.py
## DGP canonicalizer for QuadOverLin: ||x||_2^2 / y
## In log-space: log(||x||^2/y) = log(sum(x_i^2)) - log(y)
##             = log_sum_exp(2*log(x_i)) - log(y)
## Args are already in log-space, so: add_canon(explicit_sum(2*x)) - y

.dgp_quad_over_lin_canon <- function(expr, args) {
  summed <- .dgp_explicit_sum(2 * args[[1L]])
  numerator_result <- .dgp_add_canon(summed, summed@args)
  numerator <- numerator_result[[1L]]
  result <- numerator - args[[2L]]
  list(result, list())
}