Time axis object

This class represents a time axis. The functionality is provided by the CFTime class in the CFtime package.

Super classes

ncdfCF::CFObject -> ncdfCF::CFData -> ncdfCF::CFAxis -> CFAxisTime

Active bindings

friendlyClassName

(read-only) A nice description of the class.

time

(read-only) Retrieve the CFTime instance that manages the values of this axis.

dimnames

(read-only) The coordinates of the axis as a character vector.

Methods

Public methods

• CFAxisTime$new()

• CFAxisTime$print()

• CFAxisTime$brief()

• CFAxisTime$identical()

• CFAxisTime$copy()

• CFAxisTime$copy_with_values()

• CFAxisTime$append()

• CFAxisTime$indexOf()

• CFAxisTime$slice()

• CFAxisTime$subset()

• CFAxisTime$write()

Inherited methods

• ncdfCF::CFObject$append_attribute()
• ncdfCF::CFObject$attribute()
• ncdfCF::CFObject$attributes_identical()
• ncdfCF::CFObject$delete_attribute()
• ncdfCF::CFObject$print_attributes()
• ncdfCF::CFObject$set_attribute()
• ncdfCF::CFObject$write_attributes()
• ncdfCF::CFData$dim()
• ncdfCF::CFAxis$attach_to_group()
• ncdfCF::CFAxis$can_append()
• ncdfCF::CFAxis$configure_terms()
• ncdfCF::CFAxis$copy_terms()
• ncdfCF::CFAxis$detach()
• ncdfCF::CFAxis$peek()
• ncdfCF::CFAxis$shard()

---

Method new()

Create a new instance of this class, including its boundary values. A CFTime or CFClimatology instance will also be created to manage the time magic.

Creating a new time axis is more easily done with the makeTimeAxis() function.

Usage

CFAxisTime$new(
  var,
  group,
  values,
  start = 1L,
  count = NA,
  attributes = data.frame()
)

Arguments

var

The name of the axis when creating a new axis. When reading an axis from file, the NCVariable object that describes this instance.

group

The CFGroup that this instance will live in.

values

Either the numeric values of this axis, in which case argument var must be a NCVariable, or an instance of CFTime or CFClimatology with bounds set, and then argument var must be a name for the axis.

start

Optional. Integer index where to start reading axis data from file. The index may be NA to start reading data from the start.

count

Optional. Number of elements to read from file. This may be NA to read to the end of the data.

attributes

Optional. A data.frame with the attributes of the axis. When an empty data.frame (default) and argument var is an NCVariable instance, attributes of the axis will be taken from the netCDF resource.

---

Method print()

Summary of the time axis printed to the console.

Usage

CFAxisTime$print(...)

Arguments

...

Arguments passed on to other functions. Of particular interest is width = to indicate a maximum width of attribute columns.

---

Method brief()

Some details of the axis.

Usage

CFAxisTime$brief()

Returns

A 1-row data.frame with some details of the axis.

---

Method identical()

Tests if the axis passed to this method is identical to self.

Usage

CFAxisTime$identical(axis)

Arguments

axis

The CFAxisTime instance to test.

Returns

TRUE if the two axes are identical, FALSE if not.

---

Method copy()

Create a copy of this axis. The copy is completely separate from self, meaning that both self and all of its components are made from new instances.

Usage

CFAxisTime$copy(name = "", group)

Arguments

name

The name for the new axis. If an empty string is passed, will use the name of this axis.

group

The CFGroup where the copy of this axis will live.

Returns

The newly created axis.

---

Method copy_with_values()

Create a copy of this axis but using the supplied values. The attributes are copied to the new axis. Boundary values and auxiliary coordinates are not copied.

After this operation the attributes of the newly created axes may not be accurate, except for the "actual_range" attribute. The calling code should set, modify or delete attributes as appropriate.

Usage

CFAxisTime$copy_with_values(name = "", group, values)

Arguments

name

The name for the new axis. If an empty string is passed, will use the name of this axis.

group

The CFGroup where the copy of this axis will live.

values

The values to the used with the copy of this axis. This can be a CFTime instance, a vector of numeric values, a vector of character timestamps in ISO8601 or UDUNITS format, or a vector of POSIXct or Date values. If not a CFTime instance, the values will be converted into a CFTime instance using the definition and calendar of this axis.

Returns

The newly created axis.

---

Method append()

Append a vector of time values at the end of the current values of the axis.

Usage

CFAxisTime$append(from, group)

Arguments

from

An instance of CFAxisTime whose values to append to the values of this axis.

group

The CFGroup where the copy of this axis will live.

Returns

A new CFAxisTime instance with values from this axis and the from axis appended.

---

Method indexOf()

Retrieve the indices of supplied values on the time axis.

Usage

CFAxisTime$indexOf(x, method = "constant", rightmost.closed = FALSE)

Arguments

x

A vector of timestamps whose indices into the time axis to extract.

method

Extract index values without ("constant", the default) or with ("linear") fractional parts.

rightmost.closed

Whether or not to include the upper limit. Default is FALSE.

Returns

A vector giving the indices in the time axis of valid values in x, or NA if the value is not valid.

---

Method slice()

Retrieve the indices of the time axis falling between two extreme values.

Usage

CFAxisTime$slice(x, rightmost.closed = FALSE)

Arguments

x

A vector of two timestamps in between of which all indices into the time axis to extract.

rightmost.closed

Whether or not to include the upper limit. Default is FALSE.

Returns

An integer vector giving the indices in the time axis between values in x, or integer(0) if none of the values are valid.

---

Method subset()

Return an axis spanning a smaller coordinate range. This method returns an axis which spans the range of indices given by the rng argument.

Usage

CFAxisTime$subset(name = "", group, rng = NULL)

Arguments

name

The name for the new axis. If an empty string is passed (default), will use the name of this axis.

group

The CFGroup where the copy of this axis will live.

rng

The range of indices whose values from this axis to include in the returned axis. If the value of the argument is NULL, return a copy of the axis.

Returns

A new CFAxisNumeric instance covering the indicated range of indices. If the value of the argument rng is NULL, return a copy of self as the new axis.

---

Method write()

Write the axis to a netCDF file, including its attributes. If the calendar name is "gregorian", it will be set to the functionally identical calendar "standard" as the former is deprecated.

Usage

CFAxisTime$write()

Returns

Self, invisibly.