This function will plot data by month laid out in a conventional calendar format. The main purpose is to help rapidly visualise potentially complex data in a familiar way. Users can also choose to show daily mean wind vectors if wind speed and direction are available.
calendarPlot(
mydata,
pollutant = "nox",
year = 2003,
month = 1:12,
type = "default",
annotate = "date",
statistic = "mean",
cols = "heat",
limits = c(0, 100),
lim = NULL,
col.lim = c("grey30", "black"),
col.arrow = "black",
font.lim = c(1, 2),
cex.lim = c(0.6, 1),
digits = 0,
data.thresh = 0,
labels = NA,
breaks = NA,
w.shift = 0,
w.abbr.len = 1,
remove.empty = TRUE,
main = NULL,
key.header = "",
key.footer = "",
key.position = "right",
key = TRUE,
auto.text = TRUE,
plot = TRUE,
...
)an openair object
A data frame minimally containing date and at least one other
numeric variable. The date should be in either Date format or class
POSIXct.
Mandatory. A pollutant name corresponding to a variable in a
data frame should be supplied e.g. pollutant = "nox".
Year to plot e.g. year = 2003. If not supplied all data
potentially spanning several years will be plotted.
If only certain month are required. By default the function will
plot an entire year even if months are missing. To only plot certain months
use the month option where month is a numeric 1:12 e.g. month = c(1, 12) to only plot January and December.
Not yet implemented.
This option controls what appears on each day of the calendar. Can be: "date" --- shows day of the month; "wd" --- shows vector-averaged wind direction, or "ws" --- shows vector-averaged wind direction scaled by wind speed. Finally it can be “value” which shows the daily mean value.
Statistic passed to timeAverage(). Note that if statistic = "max" and annotate is "ws" or "wd", the hour corresponding to the
maximum concentration of polluant is used to provide the associated ws
or wd and not the maximum daily ws or wd.
Colours to be used for plotting. See openColours() for more
details.
Use this option to manually set the colour scale limits. This
is useful in the case when there is a need for two or more plots and a
consistent scale is needed on each. Set the limits to cover the maximum
range of the data for all plots of interest. For example, if one plot had
data covering 0--60 and another 0--100, then set limits = c(0, 100). Note
that data will be ignored if outside the limits range.
A threshold value to help differentiate values above and below
lim. It is used when annotate = "value". See next few options for
control over the labels used.
For the annotation of concentration labels on each day. The
first sets the colour of the text below lim and the second sets the
colour of the text above lim.
The colour of the annotated wind direction / wind speed arrows.
For the annotation of concentration labels on each day. The
first sets the font of the text below lim and the second sets the font of
the text above lim. Note that font = 1 is normal text and font = 2 is
bold text.
For the annotation of concentration labels on each day. The
first sets the size of the text below lim and the second sets the size of
the text above lim.
The number of digits used to display concentration values when
annotate = "value".
Data capture threshold passed to timeAverage(). For
example, data.thresh = 75 means that at least 75\
available in a day for the value to be calculate, else the data is removed.
If a categorical scale is defined using breaks, then labels
can be used to override the default category labels, e.g., labels = c("good", "bad", "very bad"). Note there is one less label than break.
If a categorical scale is required then these breaks will be
used. For example, breaks = c(0, 50, 100, 1000). In this case
“good” corresponds to values between 0 and 50 and so on. Users
should set the maximum value of breaks to exceed the maximum data value
to ensure it is within the maximum final range e.g. 100--1000 in this case.
Controls the order of the days of the week. By default the
plot shows Saturday first (w.shift = 0). To change this so that it starts
on a Monday for example, set w.shift = 2, and so on.
The default (1) abbreviates the days of the week to a
single letter (e.g., in English, S/S/M/T/W/T/F). w.abbr.len defines the
number of letters to abbreviate until. For example, w.abbr.len = 3 will
abbreviate "Monday" to "Mon".
Should months with no data present be removed? Default is
TRUE.
The plot title; default is pollutant and year.
Adds additional text/labels to the scale key. For example,
passing calendarPlot(mydata, key.header = "header", key.footer = "footer") adds addition text above and below the scale key. These
arguments are passed to drawOpenKey() via quickText(), applying the
auto.text argument, to handle formatting.
see key.header.
Location where the scale key is to plotted. Allowed
arguments currently include "top", "right", "bottom" and "left".
Fine control of the scale key via drawOpenKey(). See
drawOpenKey() for further details.
Either TRUE (default) or FALSE. If TRUE titles and
axis labels will automatically try and format pollutant names and units
properly e.g. by subscripting the `2' in NO2.
Should a plot be produced? FALSE can be useful when analysing
data to extract calendar plot components and plotting them in other ways.
Other graphical parameters are passed onto the lattice function
lattice::levelplot(), with common axis and title labelling options (such
as xlab, ylab, main) being passed to via quickText() to handle
routine formatting.
David Carslaw
calendarPlot() will plot data in a conventional calendar format, i.e., by
month and day of the week. Daily statistics are calculated using
timeAverage(), which by default will calculate the daily mean
concentration.
If wind direction is available it is then possible to plot the wind direction
vector on each day. This is very useful for getting a feel for the
meteorological conditions that affect pollutant concentrations. Note that if
hourly or higher time resolution are supplied, then calendarPlot() will
calculate daily averages using timeAverage(), which ensures that wind
directions are vector-averaged.
If wind speed is also available, then setting the option annotate = "ws"
will plot the wind vectors whose length is scaled to the wind speed. Thus
information on the daily mean wind speed and direction are available.
It is also possible to plot categorical scales. This is useful where, for
example, an air quality index defines concentrations as bands, e.g., "good",
"poor". In these cases users must supply labels and corresponding breaks.
Note that is is possible to pre-calculate concentrations in some way before
passing the data to calendarPlot(). For example rollingMean() could be
used to calculate rolling 8-hour mean concentrations. The data can then be
passed to calendarPlot() and statistic = "max" chosen, which will plot
maximum daily 8-hour mean concentrations.
Other time series and trend functions:
TheilSen(),
runRegression(),
smoothTrend(),
timePlot(),
timeProp(),
timeVariation(),
trendLevel()
# basic plot
calendarPlot(mydata, pollutant = "o3", year = 2003)
# show wind vectors
calendarPlot(mydata, pollutant = "o3", year = 2003, annotate = "wd")
if (FALSE) {
# show wind vectors scaled by wind speed and different colours
calendarPlot(mydata,
pollutant = "o3", year = 2003, annotate = "ws",
cols = "heat"
)
# show only specific months with selectByDate
calendarPlot(selectByDate(mydata, month = c(3, 6, 10), year = 2003),
pollutant = "o3", year = 2003, annotate = "ws", cols = "heat"
)
# categorical scale example
calendarPlot(mydata,
pollutant = "no2", breaks = c(0, 50, 100, 150, 1000),
labels = c("Very low", "Low", "High", "Very High"),
cols = c("lightblue", "green", "yellow", "red"), statistic = "max"
)
# UK daily air quality index
pm10.breaks <- c(0, 17, 34, 50, 59, 67, 75, 84, 92, 100, 1000)
calendarPlot(mydata, "pm10",
year = 1999, breaks = pm10.breaks,
labels = c(1:10), cols = "daqi", statistic = "mean", key.header = "DAQI"
)
}
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