A NowCast algorithm is applied to the data in in the
monitor object. The version argument specifies the minimum
weight factor and number of hours to be used in the calculation.
Available versions include:
pm: hours = 12, weight = 0.5
pmAsian: hours = 3, weight = 0.1
ozone: hours = 8, weight = NA
The default, version = "pm", is appropriate for typical usage.
monitor_nowcast(
monitor,
version = c("pm", "pmAsian", "ozone"),
includeShortTerm = FALSE
)A modified mts_monitor object. (A list with
meta and data dataframes.)
This function calculates each hour's NowCast value based on the value
for the given hour and the previous N-1 hours, where N is the number
of hours appropriate for the version argument. For example, if
version = "pm", the NowCast value for Hour 12 is based on the data
from hours 1-12.
The function returns values when at least two of the previous three hours have data. NA's are returned for hours where this condition is not met.
By default, the funtion will not return a valid value until the Nth hour.
If includeShortTerm = TRUE, the function will return a valid value
after only the 2nd hour (provided, of course, that both hours are valid).
Calculated Nowcast values are truncated to the nearest .1 ug/m3 for 'pm' and nearest .001 ppm for 'ozone' regardless of the precision of the data in the incoming mts_monitor object.