is.regular {zoo} | R Documentation |

## Check Regularity of a Series

### Description

`is.regular`

is a regular function for checking whether a series of ordered observations
has an underlying regularity or is even strictly regular.

### Usage

is.regular(x, strict = FALSE)

### Arguments

`x` |
an object (representing a series of ordered observations). |

`strict` |
logical. Should strict regularity be checked? See details. |

### Details

A time series can either be irregular (unequally spaced), strictly regular (equally spaced)
or have an underlying regularity, i.e., be created from a regular series by
omitting some observations. Here, the latter property is called *regular*.
Consequently, regularity follows from strict regularity but not vice versa.

`is.regular`

is a generic function for checking regularity (default) or
strict regularity. Currently, it has methods for `"ts"`

objects (which are
always strictly regular), `"zooreg"`

objects (which are at least regular),
`"zoo"`

objects (which can be either irregular, regular or even strictly regular)
and a default method. The latter coerces `x`

to `"zoo"`

before checking
its regularity.

### Value

A logical is returned indicating whether `x`

is (strictly) regular.

### See Also

`zooreg`

, `zoo`

### Examples

## checking of a strictly regular zoo series
z <- zoo(1:10, seq(2000, 2002.25, by = 0.25), frequency = 4)
z
class(z)
frequency(z) ## extraction of frequency attribute
is.regular(z)
is.regular(z, strict = TRUE)
## by omitting observations, the series is not strictly regular
is.regular(z[-3])
is.regular(z[-3], strict = TRUE)
## checking of a plain zoo series without frequency attribute
## which is in fact regular
z <- zoo(1:10, seq(2000, 2002.25, by = 0.25))
z
class(z)
frequency(z) ## data driven computation of frequency
is.regular(z)
is.regular(z, strict = TRUE)
## by omitting observations, the series is not strictly regular
is.regular(z[-3])
is.regular(z[-3], strict = TRUE)
## checking of an irregular zoo series
z <- zoo(1:10, rnorm(10))
z
class(z)
frequency(z) ## attempt of data-driven frequency computation
is.regular(z)
is.regular(z, strict = TRUE)

[Package

*zoo* version 1.0-5

Index]