Last data update: 2014.03.03

 R: This function extends 'continuity_ratio' and adds the...
CCGammaR Documentation

This function extends continuity_ratio and adds the corresponding gaussian correlation matrix for no-precipitation occurence.

Description

This function extends continuity_ratio and adds the corresponding gaussian correlation matrix for no-precipitation occurence.

Usage

CCGamma(data, lag = 0, p0_v1 = NULL, p = NA, valmin = 0.5,
  nearPD = (lag >= 0), interval = c(-1, 1),
  tolerance = .Machine$double.eps, only.matrix = FALSE,
  return.value = NULL, null.gcorrelation = 1e-05, sample = NULL,
  origin = "1961-1-1", ...)

Arguments

data

data frame or 'zoo' R object containing daily precipitation time series for several gauges (one gauge time series per column). See continuity_ratio.

lag

numeric lag (expressed as number of days) used for computation for "cross" continuity ratio and joint probability of prercipitation (no)occurence. See continuity_ratio.

p

positive integer parameter. Default is NA, otherwise, lag is calculated as the vector 0:p.

valmin

threshold precipitation value [mm] for wet/dry day indicator. If precipitation is lower than valmin, day is considered dry. Default is 0.5 mm. See continuity_ratio.

p0_v1

vector for marginal probablities, see omega and omega_inv.

nearPD

see omega_inv. Default is (lag==0).

interval,tolerance

see omega_inv

only.matrix

logical value. If TRUE the function returns only the gaussian correlaton matrix. Deafaul is FALSE.

return.value

string. If it is not either NULL (Default) and NA, function returns only the argument indicated by this argument.

null.gcorrelation

numerical value nooccurence_gcorrelation under which is considered to be 0.

sample

character string indicated if function must be calculated differently for subset of the year, e.g. monthly. Admitted values are NULL (Default), "all" or "monthly".

origin

character string (yyyy-dd-mm) indicated the date of the first row of "data". It is used if data and sample are not NULL.

...

additional agruments of omega_inv or CCGamma

Value

An object which is a list containing the following fields:

continuity_ratio : lag-day lagged continuity ratio, as returned by continuity_ratio;

occurence : joint probability of lag-day lagged precipitation occurence, as returned by continuity_ratio;

nooccurence : joint probability of lag-day lagged no precipitation occurence, as returned by continuity_ratio;

lag : number of days lagged between the two compared events (see argument lag);

p0_v1 : vector of marginal probability of no precipitation occurence. If lag is 0, it corresponds to the diagonal of nooccurence matrix (see argument p0_v1);

nooccurence_gcorrelation corresponding gaussian correlation for no precipitation occurence obtained by applying omega_inv to nooccurence,

If the argument only.matrix is TRUE, only nooccurence_gcorrelation is returned as a matrix. In case the argument lag is a vector wirh length more than one, the function returns a list of the above-cited return object for each value of the vector lag.

Note

This functon is useful to generate the serial cross-correlation matrices for no precipitation occurrence for Yule-Walker Equations. In case lag is a vactor, nearPD must be a vector of the same size, default is (lag==0).

See the R code for major details

Author(s)

Emanuele Cordano

References

D.S. Wilks (1998), Multisite Generalization of a Daily Stochastic Precipitation Generation Model, Journal of Hydrology, Volume 210, Issues 1-4, September 1998, Pages 178-191, http://www.sciencedirect.com/science/article/pii/S0022169498001863

Muamaraldin Mhanna and Willy Bauwens (2011) A Stochastic Space-Time Model for the Generation of Daily Rainfall in the Gaza Strip, International Journal of Climatology, Volume 32, Issue 7, pages 1098-1112, http://dx.doi.org/10.1002/joc.2305

See Also

continuity_ratio,omega_inv,omega,CCGammaToBlockmatrix

Examples

data(trentino)

year_min <- 1961
year_max <- 1990
origin <- paste(year_min,1,1,sep="-")

period <- PRECIPITATION$year>=year_min & PRECIPITATION$year<=year_max
station <- names(PRECIPITATION)[!(names(PRECIPITATION) %in% c("day","month","year"))]
prec_mes <- PRECIPITATION[period,station]

## removing nonworking stations (e.g. time series with NA)
accepted <- array(TRUE,length(names(prec_mes)))
names(accepted) <- names(prec_mes)
for (it in names(prec_mes)) {
		 accepted[it]  <- (length(which(!is.na(prec_mes[,it])))==length(prec_mes[,it]))
}

prec_mes <- prec_mes[,accepted]
## the dateset is reduced!!!
prec_mes <- prec_mes[,1:2]

CCGamma <- CCGamma(data=prec_mes,lag=0,tolerance=0.001,only.matrix=FALSE)
## Not Run in the examples, uncomment to run the following line
## CCGamma <- CCGamma(data=prec_mes,lag=0:2,tolerance=0.001,only.matrix=FALSE)

## Not Run in the examples, uncomment to run the following line
## CCGamma_monthly <- CCGamma(data=prec_mes,lag=0,tolerance=0.001,only.matrix=FALSE,
#                     sample="monthly",origin=origin)

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(RGENERATEPREC)
Loading required package: copula
Loading required package: RGENERATE
Loading required package: RMAWGEN
Loading required package: chron
Loading required package: date
Loading required package: vars
Loading required package: MASS
Loading required package: strucchange
Loading required package: zoo

Attaching package: 'zoo'

The following objects are masked from 'package:base':

    as.Date, as.Date.numeric

Loading required package: sandwich
Loading required package: urca
Loading required package: lmtest

Attaching package: 'vars'

The following object is masked from 'package:copula':

    A

Loading required package: blockmatrix
Loading required package: Matrix
Loading required package: stringr

Attaching package: 'stringr'

The following object is masked from 'package:strucchange':

    boundary

> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/RGENERATEPREC/CCGamma.Rd_%03d_medium.png", width=480, height=480)
> ### Name: CCGamma
> ### Title: This function extends 'continuity_ratio' and adds the
> ###   corresponding gaussian correlation matrix for no-precipitation
> ###   occurence.
> ### Aliases: CCGamma
> 
> ### ** Examples
> 
> data(trentino)
> 
> year_min <- 1961
> year_max <- 1990
> origin <- paste(year_min,1,1,sep="-")
> 
> period <- PRECIPITATION$year>=year_min & PRECIPITATION$year<=year_max
> station <- names(PRECIPITATION)[!(names(PRECIPITATION) %in% c("day","month","year"))]
> prec_mes <- PRECIPITATION[period,station]
> 
> ## removing nonworking stations (e.g. time series with NA)
> accepted <- array(TRUE,length(names(prec_mes)))
> names(accepted) <- names(prec_mes)
> for (it in names(prec_mes)) {
+ 		 accepted[it]  <- (length(which(!is.na(prec_mes[,it])))==length(prec_mes[,it]))
+ }
> 
> prec_mes <- prec_mes[,accepted]
> ## the dateset is reduced!!!
> prec_mes <- prec_mes[,1:2]
> 
> CCGamma <- CCGamma(data=prec_mes,lag=0,tolerance=0.001,only.matrix=FALSE)
lag
0
Hmm... p0 - first argument - must be a matrix of probabilities!!!
> ## Not Run in the examples, uncomment to run the following line
> ## CCGamma <- CCGamma(data=prec_mes,lag=0:2,tolerance=0.001,only.matrix=FALSE)
> 
> ## Not Run in the examples, uncomment to run the following line
> ## CCGamma_monthly <- CCGamma(data=prec_mes,lag=0,tolerance=0.001,only.matrix=FALSE,
> #                     sample="monthly",origin=origin)
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>


Created & Maintained by Osamu Ogasawara (osamu.ogasawara@gmail.com) and IMSBIO