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ncdfCF (version 0.2.1)

CFData: Data extracted from a CF data variable

Description

This class holds the data that is extracted from a CFVariable, using the subset() class method. The instance of this class will additionally have the axes and other relevant information such as its attributes (as well as those of the axes) and the coordinate reference system.

The class has a number of utility functions to extract the data in specific formats:

  • raw(): The data without any further processing. The axes are as they are stored in the netCDF resource; there is thus no guarantee as to how the data is organized in the array. Dimnames will be set.

  • array(): An array of the data which is organized as a standard R array with the axes of the data permuted to Y-X-others and Y-values in decreasing order. Dimnames will be set.

  • terra(): The data is returned as a terra::SpatRaster (3D) or terra::SpatRasterDataset (4D) object, with all relevant structural metadata set. Package terra must be installed for this to work.

In general, the metadata from the netCDF resource will be lost when exporting to a different format insofar as those metadata are not recognized by the different format.

Arguments

Super class

ncdfCF::CFObject -> CFData

Public fields

group

The NCGroup that this variable is defined in.

value

The data of this object. The structure of the data depends on the method that produced it. Typical structures are an array or a data.table.

axes

List of instances of classes descending from CFAxis that are the axes of the data object.

crs

Character string of the WKT2 of the CRS of the data object.

Methods

Inherited methods

Method new()

Create an instance of this class.

Usage

CFData$new(name, group, value, axes, crs, attributes)

Arguments

name

The name of the object.

group

The group that this data should live in. This is usually an in-memory group, but it could be a regular group if the data is prepared for writing into a new netCDF file.

value

The data of this object. The structure of the data depends on the method that produced it.

axes

A list of CFAxis descendant instances that describe the axes of the argument value.

crs

The WKT string of the CRS of this data object.

attributes

A data.frame with the attributes associated with the data in argument value.

Returns

An instance of this class.

Method print()

Print a summary of the data object to the console.

Usage

CFData$print()

Method raw()

Retrieve the data in the object exactly as it was produced by the operation on CFVariable.

Usage

CFData$raw()

Returns

The data in the object. This is usually an array with the contents along axes varying.

Method array()

Retrieve the data in the object in the form of an R array, with axis ordering Y-X-others and Y values going from the top down.

Usage

CFData$array()

Returns

An array of data in R ordering.

Method terra()

Convert the data to a terra::SpatRaster (3D) or a terra::SpatRasterDataset (4D) object. The data will be oriented to North-up. The 3rd dimension in the data will become layers in the resulting SpatRaster, any 4th dimension the data sets.

Usage

CFData$terra()

Returns

A terra::SpatRaster or terra::SpatRasterDataset instance.

Method clone()

The objects of this class are cloneable with this method.

Usage

CFData$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.