[R] about netcdf files

[lily li]

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.
>>>
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>> --
>> 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
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>>
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>>
>
>

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