Queue function calls defined by rows in a data.frame

Usage

Q_rows(
  df,
  fun,
  const = list(),
  export = list(),
  pkgs = c(),
  seed = 128965,
  memory = NULL,
  template = list(),
  n_jobs = NULL,
  job_size = NULL,
  rettype = "list",
  fail_on_error = TRUE,
  workers = NULL,
  log_worker = FALSE,
  chunk_size = NA,
  timeout = Inf,
  max_calls_worker = Inf,
  verbose = TRUE
)

Arguments

df: data.frame with iterated arguments
fun: A function to call
const: A list of constant arguments passed to each function call
export: List of objects to be exported to the worker
pkgs: Character vector of packages to load on the worker
seed: A seed to set for each function call
memory: Short for `template=list(memory=value)`
template: A named list of values to fill in the scheduler template
n_jobs: The number of jobs to submit; upper limit of jobs if job_size is given as well
job_size: The number of function calls per job
rettype: Return type of function call (vector type or 'list')
fail_on_error: If an error occurs on the workers, continue or fail?
workers: Optional instance of QSys representing a worker pool
log_worker: Write a log file for each worker
chunk_size: Number of function calls to chunk together defaults to 100 chunks per worker or max. 10 kb per chunk
timeout: Maximum time in seconds to wait for worker (default: Inf)
max_calls_worker: Maxmimum number of chunks that will be sent to one worker
verbose: Print status messages and progress bar (default: TRUE)

Examples

if (FALSE) {
# Run a simple multiplication for data frame columns x and y on a worker node
fx = function (x, y) x * y
df = data.frame(x = 5, y = 10)
Q_rows(df, fx, job_size = 1)
# [1] 50

# Q_rows also matches the names of a data frame with the function arguments
fx = function (x, y) x - y
df = data.frame(y = 5, x = 10)
Q_rows(df, fx, job_size = 1)
# [1] 5
}