Write run metadata

Record various types of training run metadata This function can be called even when a run directory isn't active (metadata will only be written if and when a run directory is initialized).

write_run_metadata(type, data, run_dir = NULL)



Type of metadata to write. Standard types include "flags", "sources", "properties", "metrics", and "evaluation". You can also specify a custom type (see Custom Types section below).


Metadata to write:

  • "flags" --- Named list of training flags

  • "source" --- Directory to copy source files from

  • "properties" --- Named list of arbitrary properties. Note that properties will be stored as strings.

  • "metrics" --- Data frame with training run metrics (see Metrics Data Frame below).

  • "evaluation" --- Named list of evaluation metrics.

  • "error" --- Named list with 'message' and 'traceback'

  • "<custom>" -- Function used to write the data (see Custom Types section below).


Run directory to write metadata into (defaults to currently active run)


write_run_data() is deprecated and is provided as an alias for backward compatibility.

Metrics Data Frame

Metrics should be passed as a data frame with one column for each metric. If the metrics are not yet complete (e.g. only metrics for the first several epochs are provided) then metrics in yet to be completed epochs should use NA as their values. For example:

data.frame':	30 obs. of  4 variables:
$ loss    : num  0.423 0.201 NA NA NA ...
$ acc     : num  0.873 0.942 NA NA NA ...
$ val_loss: num  0.174 0.121 NA NA NA ...
$ val_acc : num  0.949 0.964 NA NA NA ...

If both metrics and validation metrics are provided, you should preface the name of the validation metric with "val_" (e.g. for a metric named "loss" provide validation metrics in "val_loss"). This indicates that the metrics are related which is useful e.g. when plotting metrics.

Custom Types

You can pass a type with an arbitary name along with a function that should be used to writes the data. The function will be passed a single data_dir argument. For example:

write_run_metadata("images", function(data_dir) {
  # write into data_dir here