R: Read a NetCDF Dataset

read.nc {RNetCDF} | R Documentation

## Read a NetCDF Dataset

### Description

Read all data from a NetCDF dataset.

### Usage

       read.nc(ncfile, recursive=FALSE, ...)

### Arguments

`ncfile` | Object of class "`NetCDF`" which points to the NetCDF dataset (as returned from `open.nc`).
`recursive` | Descend recursively into any groups in the dataset if `TRUE`.
`...` | Optional arguments passed to `var.get.nc`.

### Details

This function reads all variable data from a NetCDF dataset into a list. The list elements (arrays) have the same names as the variables in the NetCDF dataset.

Groups in the dataset may optionally be read recursively and returned as nested lists. Each list has the name of the corresponding group in the dataset.

### Value

A list with the list elements containing an array for each variable or a (possibly nested) list for each group in the NetCDF dataset.

### Author(s)

Pavel Michna, Milton Woods

### References

https://www.unidata.ucar.edu/software/netcdf/

### Examples

    ##  Create a new NetCDF dataset
    file1 <- tempfile("read_", fileext=".nc")
    nc <- create.nc(file1, format="netcdf4")

    dim.def.nc(nc, "station", 5)
    dim.def.nc(nc, "time", unlim=TRUE)
    dim.def.nc(nc, "max_string_length", 32)

    ##  Create two coordinate variables
    var.def.nc(nc, "time", "NC_INT", "time")
    var.def.nc(nc, "name", "NC_CHAR", c("max_string_length", "station"))

    ## Create a group to contain the data
    # This is not necessary, but shows it can be done.
    grp <- grp.def.nc(nc, "data")

    ## Create a data variable
    var.def.nc(grp, "temperature", "NC_DOUBLE", c("station","time"))

    ##  Put some _FillValue attribute for temperature
    att.put.nc(grp, "temperature", "_FillValue", "NC_DOUBLE", -99999.9)

    ##  Define variable values
    mytime        <- c(1:2)
    mytemperature <- c(1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, NA, NA, 9.9)
    myname        <- c("alfa", "bravo", "charlie", "delta", "echo")

    ##  Put the data
    var.put.nc(nc, "time", mytime, 1, length(mytime))
    var.put.nc(nc, "name", myname, c(1,1), c(32,5))
    var.put.nc(grp, "temperature", mytemperature, c(1,1), c(5,2))

    sync.nc(nc)

    ##  Read the dataset, including the contents of any groups
    read.nc(nc, recursive=TRUE)

    close.nc(nc)
    unlink(file1)

[Package RNetCDF version 2.4-2 Index]