Hide recorded daily weights of the stage on purpose, fill them again with
each method and compare with the recorded values. Errors are measured on
the hidden days (filled minus recorded daily weight) and on ADG (against
the ADG of all records with the settings of weight).
All weight records of the hidden days are removed before cleaning, and the
remaining records are cleaned again with the settings of weight
(clean_weight()), so the hidden days do not decide which of the other
records are kept (before 1.5.0 the records were cleaned on all days).
Result of clean_weight().
Fill methods to compare:
"linear": linear interpolation between recorded days, the growth
curve curve_model of the settings before the first and after the
last recorded day (the method of calc_adg());
"poly1", "poly2", "poly3", "gompertz": that growth curve,
fitted on the remaining records, for every missing day.
Extrapolations of the curve beyond the records to compare
(values of curve_extrap): "start", "curve", "tangent" or
several. Default: the one of the settings of weight. Other than
"curve", a method is labelled e.g. "linear+tangent". It
matters for the days hidden at the ends ("late<d>", "early<d>").
Patterns of hidden days, as in validate_adfi():
"random<p>", "blocks<n>", "late<d>", "early<d>". Only recorded
stage days are hidden.
Number of repetitions per scenario. Default 3.
Use a random sample of at most this many pigs. Default
NULL: all.
Random seed.
0 (silent), 1 (summary and progress, default).
Number of CPU cores. Default 1.
A list of class ppt_validation with
summary: one row per scenario and method: daily_rmse and
daily_mae (kg, hidden days), daily_bias (kg), adg_bias and
adg_rmse (g/d), adg_spearman (rank correlation with the full-data
ADG) and n_pigs;
per_pig: the errors of every pig, scenario, repetition and method;
settings.