Downscale PDF {clim.pact}R Documentation

Downscale eponential PDF.

Description

Functions handy for downscaling PFDs.

DSpdf.exp() is used to downscale expeoential distributions for daily rainfall according to Benestad, R.E., C. Achberger, & E. Fernandez (2005) Empirical-statistical downscaling of distribution functions for daily precipitation, met-no report, 12-2005, Climate, pp.43 (http://met.no/english/r_and_d_activities/publications/2005/12_2005/abstract_12_2005.html). The dataset exp.law1 is used for this downscaling.

CDFtransfer() is a function that facilitates local quantile transformation.

empiricalRanking() uses a formula for estimating the cumulative probability P corresponding to rank m References: Jenkinson, A.F., 1977, U.K. Met.Office Synoptic Clim. Branch Memo 58; Beard, L.R., 1943, Trans. Amer. Meteor. Soc. Civ. Eng., 108, 1110-1160; Chegodaev, N.N., 1953 (in Russian) State Rail Transport Publishing House; Folland, C. and Anderson, C. (2002), J. Clim. 15, 2954-2960, equation (1)

Usage

DSpdf.exp(obs=NULL,dT=0,dP=0,plot=TRUE,year=NULL,month=NULL)
data(exp.law1)
CDFtransfer(Y,CDF.2,CDF.1=NULL,method="empiricalRanking",plot=FALSE,silent=FALSE,smooth=TRUE)
empiricalRanking(x)

Arguments

x A field object.
plot TRUE: plot.
obs daily station object
dT Projected change in annual mean T(2m), e.g. from objDS (unit deg C).
dP Projected change in annual mean precipitation, e.g. from objDS (units: mm/day!).
year Year to extract
month Month to extract
Y A data series or daily station object.
CDF.1 If provided, assume this CDF to describe the cumulative distribution of Y.
CDF.2 cumulative distribution predicted for the future.
method Method for estimating emprical distribution function (EDF).
silent TRUE: less clutter on the screen.
smooth Uses a 9th-order polynomial fit to provide a smoother fit for the local quantile transformation.

Value

A field object.

Author(s)

R.E. Benestad

Examples

data(exp.law1)
data(oslo.dm)
a<-DSpdf.exp(oslo.dm,dT=3,dP=1)
F1<- list(x=a$x,P=a$Fx.obs)
F2<- list(x=a$x,P=a$Fx.chg) 
y<-CDFtransfer(Y=oslo.dm$precip,CDF.2=F2,CDF.1=F1,plot=TRUE)
plot(oslo.dm$precip,y)

[Package clim.pact version 2.2-15 Index]