climatol (version 4.0.0)

QCthresholds: Obtain monthly thresholds for Quality Control alerts

Description

This function calculate monthly quantiles of daily or subdaily series that can be used as thresholds for Quality Control alerts.

Usage

QCthresholds(dat, ndec=1, probs=c(0.,.001,.01,.99,.999,1.), minval=NA,
  maxval=NA, homog=TRUE, verb=TRUE)

Arguments

dat

Either the name of a *.rda file of climatol homogenization results or a data.frame of daily (or subdaily) data in columns, dates or date/times (of class Date or POSIXct) in the first column and station codes in the header

ndec

number of decimals of output values [1] (defaults shown between brackets)

probs

probabilities of the quantiles to be computed [0., .001, .01, .99, .999, 1.]

minval

minimum value to compute runs of constant values [NA].

maxval

maximum value to compute runs of constant values [NA].

homog

use homogenized data if a *.rda file is used as input [TRUE].

verb

list all calculated values? [TRUE].

Details

minval and maxval allow to exclude frequent values that would result in the report of long runs of identical data. Examples: set minval=0.1 in daily precipitation to avoid long runs of zeros or set maxval=97 in relative humidity to avoid long runs of near saturation values in episodes of persistent fog.

Calculated thresholds are shown in the text output and are also saved in a binary R file named QCthresholds.Rdat, which contains the matrices thr1, thr2 and thr3. Load this file and write the thresholds in the required format for importation into a Climate Data Management System.

See Also

homogen

Examples

## Set a temporal working directory and write input files:
wd <- tempdir()
wd0 <- setwd(wd)
data(climatol_data)

## Now run the examples:
QCthresholds(RR3st,minval=0.1) #daily precipitation of three stations
QCthresholds(TX3st) #daily maximum temperatures of three stations
load('QCthresholds.Rdat') #load last calculated thresholds
thr1[1,,] #thresholds with 0% probability to find lower values
thr1[,3,] #monthly thresholds of the third station
thr2 #thresholds of absolute increments between consecutive data
thr3 #thresholds for equal data run lengths

## Return to user's working directory:
setwd(wd0)

## Input and output files can be found in directory:
print(wd)