templr (version 0.2-0)

tell_dY: ask&tell component function to 'tell' objective function value to waiting 'ask_Y' call in another R session.

Description

ask&tell component function to 'tell' objective function value to waiting 'ask_Y' call in another R session.

Usage

tell_dY(
  dy,
  id = 0,
  dY.tmp = "dY.done",
  tmp_path = file.path(tempdir(), "..", "asktell.tmp"),
  trace = function(...) cat(paste0(..., "\n")),
  force_cleanup = FALSE
)

Value

input value of objective function to compute externally

Arguments

dy

output value of objective function gradient to return

id

unique identifier for this asktell loop (default: "0")

dY.tmp

temporary "Y" values file (default: "dY.done")

tmp_path

temporary directory to store X.tmp & Y.tmp (default: 'tempdir()/../asktell.tmp')

trace

function to display asktell loop status (default : 'cat')

force_cleanup

should we cleanup temporary files before writing (possible conflicting asktell calls) ? (default: FALSE)

Author

Y. Richet, discussions with D. Sinoquet. Async IO principle was defined by G. Pujol.

Details

'ask&tell' injection loop to call an external objective function within an inline algorithm (like optim(...)) Main idea: pass 'ask_Y' as objectve function argument of algorithm, which will wait until you call 'tell_Y' in another R process. In this secondary process, you can read what X is called using 'ask_X', and when you know what values returns from the external objective, just call 'tell_Y' to give it.

Examples

if (FALSE)  ### Assumes you can use two independent R sessions
## In main R session
  ask_dY(x=123)
## In another R session
  ask_dX() # returns c(123, 123.123)
  tell_dY(dy=c(456,456.123))
## Then ask_dY in main R session returns with value '1'