Hi Pascal,
I think I figure it out.
By doing the following, I can made "lon" & "lat" become a class of
dim.ncdf:
lon <- seq(from=140.0251, to=146.6751, length.out=241)
lat <- seq(from=-38.975, to=-31.025, length.out=160)
x=dim.def.ncdf("Lon","degreesE",as.double(lon))
y=dim.def.ncdf("Lat","degreesN",as.double(lat))
However, after running the script, there is a error I really unable to
understand:
error at data.frame(..., check.names = FALSE) :
parameter value mean different rows 0, 31981
If you can understand what the problem is, please as kind as offer me a
direction.
Many thanks,
Jun
> Date: Wed, 4 Jul 2012 10:39:29 +0100
> From: kri...@ymail.com
> Subject: Re: [R] Please help
> To: chensh...@hotmail.com
> CC: r-help@r-project.org
>
> Hello,
>
> Following lines are wrong:
> > x=dim.def.ncdf("Lon","degreesE",140.0251:146.6751)
> > y=dim.def.ncdf("Lat","degreesN",(-31.025):(-38.975))
>
> You have 241 longitudes and 160 latitudes.
> lon <- seq(from=140.0251, to=146.6751, length.out=241)
> lat <- seq(from=-38.975, to=-31.025, length.out=160)
>
> Regards
>
>
>
> ----- Mail original -----
> De : Jun Chen <chensh...@hotmail.com>
> À : r-help@r-project.org
> Cc :
> Envoyé le : Mercredi 4 juillet 2012 10h52
> Objet : [R] Please help
>
>
> Dear All,
> I am a research student in environment. I have only little
> programming knowledge. I am currently doing the last project about rainfall
> impact on ground water quality in an area. It happens that I have to use R to
> read rainfall data (3 dimension) from ASC file (*.asc), and then write them
> into one NCDF file (*.nc).
>
> I have been working very hard on study R, but I still can not fix
> the problem. Could someone please as kind as point out that what the problems
> are in my R script?
>
> Firstly, this is an example of data in asc file:
> NCOLS 241
>
> NROWS 160
>
> XLLCORNER 140.00012207031
>
> YLLCORNER -39.000000000000
>
> CELLSIZE 0.50000000000000E-01
>
> NODATA_VALUE -99.00000
>
> 166.30 160.87 155.23 149.33 143.83 138.52 133.29
> 128.34 123.76 119.21
>
> 115.06 110.90 107.22 103.69 100.40 97.29 94.58
> 92.15 90.00 87.91
>
> 86.20 84.57 83.22 81.94 81.11 80.38 79.37 78.73
> 79.70 79.62
>
> -----------------------------------------------------------------------------------------------------------------------
>
>
>
>
> And then this is the script I wrote:
>
> setwd("E:/grid")
>
> #defining dimension
>
> x=dim.def.ncdf("Lon","degreesE",140.0251:146.6751)
>
> y=dim.def.ncdf("Lat","degreesN",(-31.025):(-38.975))
>
> t=dim.def.ncdf("Time","1968-01",1:12,unlim=TRUE)
>
>
>
> #setup variable
>
> varmr=var.def.ncdf("mr","mm",list(x,y,t),-99.00,
>
> longname="monthly rainfall")
>
>
> #create ncdf file
>
> ncnew=create.ncdf("rainfall.nc", varmr)
>
>
> #read input
>
> files=list.files(pattern=".asc")
>
> mrain=matrix(0:0,0,3)
>
>
> for(i in files)
>
> {rainfall=data.frame(readAsciiGrid(i))
>
> mrain=cbind(mrain,rainfall)
>
> }
>
> put.var.ncdf(ncnew, mrain)
>
>
> close.ncdf(ncnew)
>
> -------------------------------------------------------------------------------
>
> [[elided Hotmail spam]]
>
>
>
>
>
> Many thanks,
> Jun
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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