[R] about netcdf files

[lily li]

Thanks, Roy. I will do a search. In addition, how to look at spatial
patterns from this netcdf file? Thanks again.

On Mon, Aug 1, 2016 at 11:46 AM, Roy Mendelssohn - NOAA Federal <
roy.mendelssohn at noaa.gov> wrote:

> Hi Lily:
>
> If you download the vignette to my xtractomatic package  (
> http://coastwatch.pfeg.noaa.gov/xtracto/index.html) there are any number
> of examples using ggplot2 to make maps from netcdf data,
>
> HTH,
>
> -Roy
>
> > On Aug 1, 2016, at 10:35 AM, lily li <chocold12 at gmail.com> wrote:
> >
> > Hi all,
> >
> > I can read the data, but how to plot it using ggplot or something? In
> this
> > case, x-axis should be longitude, and y-axis should be latitude. I tried
> to
> > plot using raster function, but the x and y axes are from 0 to 1.
> > Thanks again.
> >
> > The code is like this:
> > pre1 = nc_open('sample_precip_daily.nc')
> > pre.3d = ncvar_get(pre1, 'precipitation')
> >
> > require(raster)
> > rplot = t(pre.3d[, , 1])
> > r = raster(rplot[nrow(rplot):1, ]
> > plot(r)
> >
> >
> > On Tue, Jul 26, 2016 at 1:07 PM, lily li <chocold12 at gmail.com> wrote:
> >
> >> Thanks for your reply. But it says "Error in (function (classes, fdef,
> >> mtable)):
> >> unable to find an inherited method for function 'brick' for signature
> >> 'ncdf4' "
> >>
> >> The dataset is attached. It contains daily precipitation data for 20
> >> years, within a rectangle, so that there are several grid points. I use
> the
> >> code to open it, but don't know how to get csv files, while each file
> >> contains continuous daily precipitation data for each grid cell.
> >> pre1 = nc_open('sample_precip_daily.nc')
> >> pre1
> >> pre1_rd = ncvar_get(pre1, 'precipitation')
> >> nc_close(pre1)
> >>
> >> Thanks for your help.
> >>
> >> On Tue, Jul 26, 2016 at 4:08 AM, Jon Skoien <
> jon.skoien at jrc.ec.europa.eu>
> >> wrote:
> >>
> >>> You could try with the brick function from the raster package.
> >>>
> >>> bvar = brick(netcdfName)
> >>>
> >>> This uses the ncdf4 functions for opening and reading the netcdf, but
> >>> makes it easier to extract data for each day:
> >>>
> >>> p1 = rasterToPoints(bvar[[1]])
> >>> and write p1 to csv.
> >>>
> >>> Best,
> >>> Jon
> >>>
> >>>
> >>>
> >>> On 7/26/2016 6:54 AM, lily li wrote:
> >>>
> >>>> Hi all,
> >>>>
> >>>> I have a problem in opening netcdf files. If one netcdf file contains
> >>>> longitude, latitude, and daily precipitation. How to relate each
> >>>> precipitation record to its associated location, and export them as
> csv
> >>>> files? Thanks.
> >>>>
> >>>> I just use nc_open(), ncvar_get(), but it is not very helpful. Thanks
> for
> >>>> any ideas.
> >>>>
> >>>>        [[alternative HTML version deleted]]
> >>>>
> >>>> ______________________________________________
> >>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>>> 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.
> >>>>
> >>>>
> >>> --
> >>> Jon Olav Skøien
> >>> Joint Research Centre - European Commission
> >>> Institute for Space, Security & Migration
> >>> Disaster Risk Management Unit
> >>>
> >>> Via E. Fermi 2749, TP 122,  I-21027 Ispra (VA), ITALY
> >>>
> >>> jon.skoien at jrc.ec.europa.eu
> >>> Tel:  +39 0332 789205
> >>>
> >>> Disclaimer: Views expressed in this email are those of the individual
> and
> >>> do not necessarily represent official views of the European Commission.
> >>>
> >>
> >>
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
>
> **********************
> "The contents of this message do not reflect any position of the U.S.
> Government or NOAA."
> **********************
> Roy Mendelssohn
> Supervisory Operations Research Analyst
> NOAA/NMFS
> Environmental Research Division
> Southwest Fisheries Science Center
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>
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> "the arc of the moral universe is long, but it bends toward justice" -MLK
> Jr.
>
>

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