R: Inquire About a NetCDF Group

grp.inq.nc {RNetCDF} | R Documentation

## Inquire About a NetCDF Group

### Description

Inquire about a NetCDF group.

### Usage

    grp.inq.nc(ncid,grpname=NULL,ancestors=TRUE)

### Arguments

`ncid` | Object of class "`NetCDF`" which points to a NetCDF group (from `grp.def.nc`) or dataset (from `open.nc`).
`grpname` | By default, the inquiry relates to the group represented by `ncid`. If `grpname` is a character string, a group with this name is examined instead. A hierarchical search is performed if `grpname` contains "/", otherwise only the immediate group of `ncid` is searched for a matching group name.
`ancestors` | If `TRUE`, dimensions and names of ancestor groups are examined. Otherwise, only dimensions and names defined in the current group are reported.

### Details

This function provides information about the structure of a NetCDF group or dataset. The results allow programs to explore a dataset without prior knowledge of the contents.

### Value

A list containing the following components:

`self` | Object of class `NetCDF` representing the group.
`parent` | Object of class `NetCDF` representing the parent group, or `NULL` for the root group.
`grps` | List of objects of class `NetCDF` representing the groups in the group.
`name` | Name of the NetCDF group.
`fullname` | Full name of the NetCDF group, with ancestors listed in order from the root group of the dataset and separated by "/". Omitted if `ancestors` is `FALSE`.
`dimids` | Vector of dimension identifiers. If `ancestors` is `TRUE` (default), all visible dimensions in the group and its ancestors are reported, otherwise only dimensions defined in the group of `ncid` are shown.
`unlimids` | Vector of identifiers for unlimited dimensions. If `ancestors` is `TRUE` (default), all unlimited dimensions in the group and its ancestors are reported, otherwise only unlimited dimensions defined in the group of `ncid` are shown.
`varids` | Vector of identifiers for variables in the group.
`typeids` | Vector of identifiers for types in the group.
`ngatts` | Number of group attributes.

### Author(s)

Pavel Michna, Milton Woods

### References

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

### Examples

    ##  Create a new NetCDF dataset and define two dimensions
    file1 <- tempfile("grp.inq_", fileext=".nc")
    nc <- create.nc(file1)

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

    ##  Create two variables, one as coordinate variable
    var.def.nc(nc, "time", "NC_INT", "time")
    var.def.nc(nc, "temperature", "NC_DOUBLE", c(0,1))

    ##  Put some attributes
    att.put.nc(nc, "NC_GLOBAL", "title", "NC_CHAR", "Data from Foo")
    att.put.nc(nc, "NC_GLOBAL", "history", "NC_CHAR", paste("Created on", date()))

    ##  Inquire about the root group
    grp.inq.nc(nc)

    close.nc(nc)
    unlink(file1)

[Package RNetCDF version 2.4-2 Index]