R: Inquire About a NetCDF Attribute

att.inq.nc {RNetCDF} | R Documentation

## Inquire About a NetCDF Attribute

### Description

Inquire about a NetCDF attribute.

### Usage

    att.inq.nc(ncfile, variable, attribute)

### Arguments

`ncfile` | Object of class "`NetCDF`" which points to the NetCDF dataset (as returned from `open.nc`).
`variable` | Either the ID or the name of the attribute's variable or `"NC_GLOBAL"` for a global attribute.
`attribute` | Either the ID or the name of the attribute to be inquired.

### Details

This function returns information about a NetCDF attribute. Information about an attribute include its ID, its name, its type, and its length. In general, attributes are accessed by name rather than by their ID number because the attribute number is more volatile than the name, since it can change when other attributes of the same variable are deleted.

### Value

A list containing the following components:

`id` | Attribute ID.
`name` | Attribute name.
`type` | External NetCDF data type as one of the following labels: `NC_BYTE`, `NC_UBYTE`, `NC_CHAR`, `NC_SHORT`, `NC_USHORT`, `NC_INT`, `NC_UINT`, `NC_INT64`, `NC_UINT64`, `NC_FLOAT`, `NC_DOUBLE`, `NC_STRING`, or a user-defined type name.
`length` | Length of this attribute.

### 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("att.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, "temperature", "_FillValue", "NC_DOUBLE", -99999.9)
    att.put.nc(nc, "NC_GLOBAL", "title", "NC_CHAR", "Data from Foo")

    ##  Inquire about these attributes
    att.inq.nc(nc, "temperature", "_FillValue")
    att.inq.nc(nc, "NC_GLOBAL", "title")

    close.nc(nc)
    unlink(file1)

[Package RNetCDF version 2.4-2 Index]