This class is a basic ancestor to all classes that represent CF axes. More useful classes use this class as ancestor.
This super-class does manage the "coordinates" of the axis, i.e. the values along the axis. This could be the values of the axis as stored on file, but it can also be the values from an auxiliary coordinate set, in the form of a CFLabel instance. The coordinate set to use in display, selection and processing is selectable through methods and fields in this class.
ncdfCF::CFObject -> CFAxis
NCdimThe NCDimension that stores the netCDF dimension details.
orientationA character "X", "Y", "Z" or "T" to indicate the orientation of the axis, or an empty string if not known or different.
boundsThe boundary values of this axis, if set.
friendlyClassName(read-only) A nice description of the class.
dimid(read-only) The netCDF dimension id of this axis.
length(read-only) The declared length of this axis.
values(read-only) Retrieve the raw values of the axis. In general
you should use the coordinates field rather than this one.
coordinates(read-only) Retrieve the coordinate values of the active coordinate set from the axis.
auxiliarySet or retrieve auxiliary coordinates for the axis. On
assignment, the value must be an instance of CFLabel or a CFAxis
descendant, which is added to the end of the list of coordinate sets.
On retrieval, the active CFLabel or CFAxis instance or NULL when
the active coordinate set is the primary axis coordinates.
coordinate_namesRetrieve the names of the coordinate sets defined for the axis, as a character vector. The first element in the vector is the name of the axis and it refers to the values of the coordinates as stored in the netCDF file. Following elements refer to auxiliary coordinates.
active_coordinatesSet or retrieve the name of the coordinate set
to use with the axis for printing to the console as well as for
processing methods such as subset().
unlimited(read-only) Logical to indicate if the axis has an unlimited dimension.
new()Create a new CF axis instance from a dimension and a
variable in a netCDF resource. This method is called upon opening a
netCDF resource by the initialize() method of a descendant class
suitable for the type of axis.
Creating a new axis is more easily done with the makeAxis() function.
CFAxis$new(nc_var, nc_dim, orientation)nc_varThe NCVariable instance upon which this CF axis is based.
nc_dimThe NCDimension instance upon which this CF axis is based.
orientationThe orientation of the axis: "X", "Y", "Z" "T", or "" when not known or relevant.
A basic CFAxis object.
print()Prints a summary of the axis to the console. This method is
typically called by the print() method of descendant classes.
CFAxis$print(...)...Arguments passed on to other functions. Of particular interest
is width = to indicate a maximum width of attribute columns.
self, invisibly.
brief()Some details of the axis.
CFAxis$brief()A 1-row data.frame with some details of the axis.
shard()Very concise information on the axis. The information returned by this function is very concise and most useful when combined with similar information from other axes.
CFAxis$shard()Character string with very basic axis information.
peek()Retrieve interesting details of the axis.
CFAxis$peek(with_groups = TRUE)with_groupsShould group information be included? The safe option
is TRUE (default) when the netCDF resource has groups because names may
be duplicated among objects in different groups.
A 1-row data.frame with details of the axis.
time()Return the CFTime instance that represents time. This
method is only useful for CFAxisTime instances having time
information. This stub is here to make the call to this method succeed
with no result for the other descendant classes.
CFAxis$time()NULL
identical()Tests if the axis passed to this method is identical to
self. This only tests for generic properties - class, length and name
with further assessment done in sub-classes.
CFAxis$identical(axis)axisThe CFAxis instance to test.
TRUE if the two axes are identical, FALSE if not.
can_append()Tests if the axis passed to this method can be appended to
self. This only tests for generic properties - class, mode of the
values and name - with further assessment done in sub-classes.
CFAxis$can_append(axis)axisThe CFAxis descendant instance to test.
TRUE if the passed axis can be appended to self, FALSE if
not.
subset()Return an axis spanning a smaller coordinate range. This
method is "virtual" in the sense that it does not do anything other
than return NULL. This stub is here to make the call to this method
succeed with no result for the CFAxis descendants that do not
implement this method.
CFAxis$subset(group, rng = NULL)groupThe group to create the new axis in.
rngThe range of indices whose values from this axis to include in
the returned axis. If the value of the argument is NULL, return the
entire axis.
NULL
indexOf()Find indices in the axis domain. Given a vector of
numerical, timestamp or categorical coordinates x, find their indices
in the coordinates of the axis.
This is a virtual method. For more detail, see the corresponding method in descendant classes.
CFAxis$indexOf(x, method = "constant", rightmost.closed = TRUE)xVector of numeric, timestamp or categorial coordinates to find axis indices for. The timestamps can be either character, POSIXct or Date vectors. The type of the vector has to correspond to the type of the axis values.
methodSingle character value of "constant" or "linear".
rightmost.closedWhether or not to include the upper limit.
Default is TRUE.
Numeric vector of the same length as x.
write()Write the axis to a netCDF file, including its attributes.
CFAxis$write(nc = NULL)ncThe handle of the netCDF file opened for writing or a group in
the netCDF file. If NULL, write to the file or group where the axis
was read from (the file must have been opened for writing). If not
NULL, the handle to a netCDF file or a group therein.
Self, invisibly.
clone()The objects of this class are cloneable with this method.
CFAxis$clone(deep = FALSE)deepWhether to make a deep clone.