This function takes a data frame that contains a field date and other
variables and adds other common variables needed by the modelling functions.
This function is run automatically by buildMod() but can be used separately
for further analysis. These variables include:
hour - The hour of the day from 0 to 23.
hour.local - The hour in the local time zone. Note that the local time zone will need to be supplied (see
local.tz). The purpose of using local time rather than UTC is that emissions can vary more strongly by local time rather than UTC.weekday - The day of the week.
trend - The trend is calculated as a decimal year.
week - The week of the year. Useful for taking account of long-term seasonal variations.
jday - The Julian Day number.
month - month of the year. Useful for taking account of long-term seasonal variations.
Usage
prepData(
mydata,
add = c("hour", "hour.local", "weekday", "trend", "week", "jday", "month"),
local.tz = "Europe/London",
lag = NULL
)Arguments
- mydata
A data frame to process.
- add
Names of explanatory variables to include.
- local.tz
Used if hour needs to be expressed in local time. This can be useful for situations where the anthropogenic emissions source is strong and follows local time rather than UTC.
- lag
Variables(s) to lag. Any variables included here will add new columns to the data frame. For example
lag = "ws"with add a new columnslag1ws. Adding some variables here can improve the explanatory power of the models. Variables are lagged by one unit of time.