Check that observed values are constant within each forecast unit

Helper function that checks that all rows belonging to the same forecast (as defined by the forecast unit) share a single observed value. Rows where observed is NA are ignored. If the observed values are constant within each forecast unit, the function returns TRUE and a string with an error message otherwise.

Usage

check_observed_constant(data, forecast_unit)

Arguments

data

A data.frame or similar to be checked

forecast_unit

Character vector denoting the unit of a single forecast.

Value

Returns TRUE if the check was successful and a string with an error message otherwise.