calculate_ps {AeRobiology} | R Documentation |
Function to calculate the main parameters of the pollen season with regard to phenology and pollen intensity from a historical database of several pollen types. The function can use the most common methods in the definition of the pollen season.
calculate_ps(data, method = "percentage", th.day = 100, perc = 95, def.season = "natural", reduction = FALSE, red.level = 0.9, derivative = 5, man = 11, th.ma = 5, n.clinical = 5, window.clinical = 7, window.grains = 5, th.pollen = 10, th.sum = 100, type = "none", interpolation = TRUE, int.method = "lineal", maxdays = 30, result = "table", plot = TRUE, export.plot = FALSE, export.result = FALSE)
data |
A |
method |
A |
th.day |
A |
perc |
A |
def.season |
A |
reduction |
A |
red.level |
A |
derivative |
A |
man |
A |
th.ma |
A |
n.clinical |
A |
window.clinical |
A |
window.grains |
A |
th.pollen |
A |
th.sum |
A |
type |
A |
interpolation |
A |
int.method |
A |
maxdays |
A |
result |
A |
plot |
A |
export.plot |
A |
export.result |
A |
This function allows to calculate the pollen season using five different methods which are described below. After calculating the start_date, end_date and peak_date for the pollen season all rest of parameters have been calculated as detailed in Value section.
"percentage"
method. This is a commonly used method for defining the pollen season based on the elimination of a certain percentage in the beginning and the end of the pollen season (Nilsson and Persson, 1981; Andersen, 1991). For example if the pollen season is based on the 95% of the total annual pollen ("perc" = 95
), the start_date of the pollen season is marked as the day in which 2.5% of the total pollen is registered and the end_date of the pollen season is marked as the day in which 97.5% of the total pollen is registered.
"logistic"
method. This method was developed by Ribeiro et al. (2007) and modified by Cunha et al. (2015). It is based on fitting annually a non_linear logistic regression model to the daily accumulated curve for each pollen type. This logistic function and the different derivatives were considered to calculate the start_date and end_date of the pollen season, based on the asymptotes when pollen amounts are stabilized on the beginning and the end of the accumulated curve. For more information about the method to see Ribeiro et al. (2007) and Cunha et al. (2015). Three different derivatives may be used (derivative
argument) 4
, 5
or 6
that represent from higher to lower restrictive criterion for defining the pollen season. This method may be complemented with an optional method for reduction the peaks values (reduction = TRUE
), thus avoiding the effect of the great influence of extreme peaks. In this sense, peaks values will be cut below a certain level that the user may select based on a percentile analysis of peaks. For example, red.level = 0.90
will cut all peaks above the percentile 90
.
"moving"
method. This method is proposed the first time by the authors of this package. The definition of the pollen season is based on the application of a moving average to the pollen series in order to obtain the general seasonality of the pollen curve avoiding the great variability of the daily fluctuations. Thus, the start_date and the end_date will be established when the curve of the moving average reaches a given pollen threshold (th.ma
argument). Also the order of the moving average may be customized by the user (man
argument). By default, man
= 11 and th.ma
= 5.
"clinical"
method. This method was proposed by Pfaar et al. (2017). It is based on the expert consensus in relation to pollen exposure and the relationship with allergic symptoms derived of the literature. Different periods may be defined by this method: the pollen season, the high pollen season and the high pollen days. The start_date and end_date of the pollen season were defined as a certain number of days (n.clinical
argument) within a time window period (window.clinical
argument) exceeding a certain pollen threshold (th.pollen
argument) which summation is above a certain pollen sum (th.sum
argument). All these parameters are established for each pollen type according to Pfaar et al. (2017) and using the type
argument these parameters may be automatically adjusted for the specific pollen types ("birch"
, "grasses"
, "cypress"
, "olive"
or "ragweed"
). Furthermore, the user may change all parameters to do a customized definition of the pollen season. The start_date and end_date of the high pollen season were defined as three consecutive days exceeding a certain pollen threshold (th.day
argument). The number of high pollen days will also be calculated exceeding this pollen threshold (th.day
). For more information about the method to see Pfaar et al. (2017).
"grains"
method. This method was proposed by Galan et al. (2001) originally in olive pollen but after also applied in other pollen types. The start_date and end_date of the pollen season were defined as a certain number of days (window.grains
argument) exceeding a certain pollen threshold (th.pollen
argument). For more information about the method to see Galan et al. (2001).
The pollen season of the species may occur during the natural year (Calendar year: from 1. January to 31. December) or the start_date and the end_date of the pollen season may happen in two different natural years (or calendar years). This consideration has been taken into account and in this package different method for defining the period for calculating the pollen season have been implemented. In this sense, the def.season
argument has been incorporated in three options:
"natural"
: considering the pollination year as natural year from 1st January to 31th December for defining the start_dates and end_dates of the pollen season for each pollen types.
"interannual"
: considering the pollination year from 1st June to 31th May for defining the start_dates and end_dates of the pollen season for each pollen types.
"peak"
: considering a customized pollination year for each pollen types calculated as 6 previous months and 6 later months from the average peak_date.
Pollen time series frequently have different gaps with no data and this fact could be a problem for the calculation of specific methods for defining the pollen season even providing incorrect results. In this sense by default a linear interpolation will be carried out to complete these gaps before to define the pollen season (interpolation = TRUE
). Additionally, the users may select other interpolation methods using the int.method
argument, as "lineal"
, "movingmean"
, "spline"
or "tseries"
. For more information to see the interpollen
function.
This function returns different results:
data.frame
when result = "table"
including the main parameters of the pollen season with regard to phenology and pollen intensity as:
type: pollen type
seasons: year of the beginning of the season
st.dt: start_date (date)
st.jd: start_date (day of the year)
en.dt: end_date (date)
en.jd: end_date (day of the year)
ln.ps: length of the season
sm.tt: total sum
sm.ps: pollen integral
pk.val: peak value
pk.dt: peak_date (date)
pk.jd: peak_date (day of year)
ln.prpk: length of the pre_peak period
sm.prpk: pollen integral of the pre_peak period
ln.pspk: length of the post_peak period
sm.pspk: pollen integral of the post_peak period
daysth: number of days with more than 100 pollen grains
st.dt.hs: start_date of the High pollen season (date, only for clinical method)
st.jd.hs: start_date of the High pollen season (day of the year, only for clinical method)
en.dt.hs: end_date of the High pollen season (date, only for clinical method)
en.jd.hs: end_date of the High pollen season (day of the year, only for clinical method)
list
when result = "list"
including the main parameters of the pollen season, one pollen type by element
plots
when plot = TRUE
showing graphically the definition of the pollen season for each studied year in the plot history.
If export.result = TRUE
this data.frame
will also be exported as xlsx file within the table_AeRobiology directory created in the working directory. If export.result = FALSE
the results will also be showed as list object named list.ps
.
If export.plot = TRUE
a pdf file for each pollen type showing graphically the definition of the pollen season for each studied year will be saved within the plot_AeRobiology directory created in the working directory.
Andersen, T.B., 1991. A model to predict the beginning of the pollen season. Grana, 30(1), pp.269_275.
Cunha, M., Ribeiro, H., Costa, P. and Abreu, I., 2015. A comparative study of vineyard phenology and pollen metrics extracted from airborne pollen time series. Aerobiologia, 31(1), pp.45_56.
Galan, C., Garcia_Mozo, H., Carinanos, P., Alcazar, P. and Dominguez_Vilches, E., 2001. The role of temperature in the onset of the Olea europaea L. pollen season in southwestern Spain. International Journal of Biometeorology, 45(1), pp.8_12.
Nilsson, S. and Persson, S., 1981. Tree pollen spectra in the Stockholm region (Sweden), 1973_1980. Grana, 20(3), pp.179_182.
Pfaar, O., Bastl, K., Berger, U., Buters, J., Calderon, M.A., Clot, B., Darsow, U., Demoly, P., Durham, S.R., Galan, C., Gehrig, R., Gerth van Wijk, R., Jacobsen, L., Klimek, L., Sofiev, M., Thibaudon, M. and Bergmann, K.C., 2017. Defining pollen exposure times for clinical trials of allergen immunotherapy for pollen_induced rhinoconjunctivitis_an EAACI position paper. Allergy, 72(5), pp.713_722.
Ribeiro, H., Cunha, M. and Abreu, I., 2007. Definition of main pollen season using logistic model. Annals of Agricultural and Environmental Medicine, 14(2), pp.259_264.
data("munich_pollen") calculate_ps(munich_pollen, plot = TRUE, result = "table")