seas (version 0.2-1)

sdsm: Read and write from SDSM

Description

Reads and writes the data format used in SDSMs DAT and OUT extensions.

Usage

# reading
read.sdsm(file, start = 1961, end = 2000, year.length = 366)
read.sdsm(file)
# writing
write.sdsm(dat, var, start, end, file)
write.sdsm(dat, var)

Arguments

file

name of DAT or OUT file

dat

data.frame of variables to be written

start

starting year

end

ending year

var

name of variable to be written from dat

year.length

maximum allowable year length; this is usually 366 for measured data, 365 for CCCma model data and 360 for Hadley model data

Value

• read.sdsm returns a data.frame of the measured variables. The variables are named V1...Vn, for n ensembles.

synopsis

read.sdsm(file, start = 1961, end = 2000, year.length = 366) write.sdsm(dat, var, start, end, file = "")

Details

This function readings and writes climate data with the Statistical Downscaling Model, or SDSM. The model uses DAT extensions for input data, such as daily observations of mean temperature, and OUT extensions for modeled output.

Since the files used by SDSM do not have any meta-data, read.sdsm attempts to interpret this from the filename, otherwise this needs to be specified. The following table shows how this decision is made: llll{ grep start end year.length Cal 1961 2000 366 Cur 1961 2000 365 2020 2010 2039 365 2050 2040 2069 365 2050 2070 2099 365 }

References

Wilby, R.L., Dawson, C.W. and Barrow, E.M. 2002, SDSM - a decision support tool for the assessment of regional climate change impacts, Environmental Modelling Software, 77, 473--471.

SDSM can be downloaded free-of-charge for Windows platforms from http://www-staff.lboro.ac.uk/~cocwd/SDSM/ CGCM1 and HADCM3 model data for SDSM can be downloaded from the Canadian Climate Impacts and Scenarios website: http://www.cics.uvic.ca/scenarios/sdsm/select.cgi

See Also

read.msc

Examples

# reading
gf50 <- read.sdsm("GF_2050s_precip.OUT")
gf50.ss <- seas.sum(gf50,var=paste("V",1:20,sep=""),name="Grand Forks")
# analysis
image(gf50.ss,var="V1")
image(gf50.ss,var="V2")
image(gf50.ss,var="V3")

# writing
data(mscdata)
hj <- mksub(mscdata,id=2100630)
write.sdsm(hj,"precip",1961,2000,"HJ_Obs_prcp.DAT")