Issue when running budget allocator with 0-constraint channels but no 0-coef channels

[m4x3]

Issue

The budget allocator does not run correctly for a model if the model has no non-zero coefficients for any channel and some channels are forced to zero via the constraints. --> relevant code here:

In the below code channel_for_allocation is a vector that stores the channels with either 0 coefs (zero_coef_channel) or 0 constraints (zero_coef_channel). These channels are supposed to be ignored for the budget allocation.

This code if (length(zero_coef_channel) > 0) {...} is only executed if there are 0 coef channels. If all channels are non-zero, it does not get executed, even if some channels should be forced to 0 via the constraints.

## Exclude 0 coef and 0 constraint channels for the optimisation
  skip_these <- (channel_constr_low == 0 & channel_constr_up == 0)
  zero_constraint_channel <- mediaSpendSorted[skip_these]
  if (any(skip_these) && !quiet) {
    message("Excluded variables (constrained to 0): ", zero_constraint_channel)
  }
  if (!all(coefSelectorSorted)) {
    zero_coef_channel <- setdiff(names(coefSelectorSorted), mediaSpendSorted[coefSelectorSorted])
    if (!quiet) message(
      "Excluded variables (coefficients are 0): ",
      paste(zero_coef_channel, collapse = ", "))
  } else {
    zero_coef_channel <- as.character()
  }
  channel_for_allocation_loc <- mediaSpendSorted %in% c(zero_coef_channel, zero_constraint_channel)
  channel_for_allocation <- mediaSpendSorted[!channel_for_allocation_loc]
  if (length(zero_coef_channel) > 0) {
    temp_init <- temp_init_all[channel_for_allocation]
    temp_ub <- temp_ub_all[channel_for_allocation]
    temp_lb <- temp_lb_all[channel_for_allocation]
    temp_ub_ext <- temp_ub_ext_all[channel_for_allocation]
    temp_lb_ext <- temp_lb_ext_all[channel_for_allocation]
    x0 <- x0_all[channel_for_allocation]
    lb <- lb_all[channel_for_allocation]
    ub <- ub_all[channel_for_allocation]
    x0_ext <- x0_ext_all[channel_for_allocation]
    lb_ext <- lb_ext_all[channel_for_allocation]
    ub_ext <- ub_ext_all[channel_for_allocation]
  }

Proposed Solution

I think here it should therefore rather be: if (length(zero_coef_channel) > 0 | length(zero_constraint_channel) > 0) {...}

[gufengzhou]

Hi thanks for raising this! So far it looks like you're right. I'll test a bit more and let you know.

[gufengzhou]

just pushed a fix. please reopen if necessary