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Last data update: 2014.03.03

R: Calculates mean bias (difference between (max+min)/2 and...

bias	R Documentation

Calculates mean bias (difference between (max+min)/2 and 24-hour averages) in mean daily temperature series

Description

Calculates the average difference between the series of mean daily temperatures calculated by (Tmax + Tmin) / 2 and the average calculated by 24 hourly values a day, as resulting from the interpolation (or from measurements). The function works on data tables with series on columns.

Usage

  bias(TMIN, TMAX, TMEAN, min_valid = 21)

Arguments

`TMIN`	data frame with daily minimum temperatures in columns. The first 3 columns are skipped (dates as year, month and day are supposed to be stored in these columns)
`TMAX`	same for TMAX
`TMEAN`	same for TMEAN. Should come from 24-hour daily means.
`min_valid`	min nr. of valid days in a month for retaining its average value (if valid days are fewer, monthly value is `NA`). Default is 21.

Value

A vector of means of daily biases, where the TMEAN is considered the "true" (reference) value

Note

Biases are calculated only on columns that are present in both TMIN/TMAX and TMEAN

Author(s)

Emanuele Eccel, Emanuele Cordano emanuele.eccel@iasma.it

References

Eccel, E., 2010: What we can ask to hourly temperature recording. Part II: hourly interpolation of temperatures for climatology and modelling. Italian Journal of Agrometeorology XV(2):45-50 http://www.agrometeorologia.it/documenti/Rivista2010_2/AIAM%202-2010_pag45.pdf,www.agrometeorologia.it

See also: Eccel, E., 2010: What we can ask to hourly temperature recording. Part I: statistical vs. meteorological meaning of minimum temperature. Italian Journal of Agrometeorology XV(2):41-43. http://www.agrometeorologia.it/documenti/Rivista2010_2/AIAM%202-2010_pag41.pdf,www.agrometeorologia.it

Examples

data(Trentino_hourly_T)
mo_bias <- bias(TMIN = Tn, TMAX = Tx, TMEAN = Tm_list, min_valid = 20)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(Interpol.T)
Loading required package: date
Loading required package: chron
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/Interpol.T/bias.Rd_%03d_medium.png", width=480, height=480)
> ### Name: bias
> ### Title: Calculates mean bias (difference between (max+min)/2 and 24-hour
> ###   averages) in mean daily temperature series
> ### Aliases: bias
> 
> ### ** Examples
> 
> data(Trentino_hourly_T)
> mo_bias <- bias(TMIN = Tn, TMAX = Tx, TMEAN = Tm_list, min_valid = 20)
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>