• Decomposed Body
• Decompose Numbers
• Decompose
• Decompose Defined
• Decompose Etymology

Syntax

Description of the illustration decompose.gif

Purpose

Human decomposition is a natural process involving the breakdown of tissues after death. While the rate of human decomposition varies due to several factors, including weather, temperature, moisture, pH and oxygen levels, cause of death, and body position, all human bodies follow the. Decompose definition, to separate or resolve into constituent parts or elements; disintegrate: The bacteria decomposed the milk into its solid and liquid elements.

DECOMPOSE is valid only for Unicode characters. DECOMPOSE takes as its argument a string in any datatype and returns a Unicode string after decomposition in the same character set as the input. For example, an o-umlaut code point will be returned as the 'o' code point followed by an umlaut code point.

• string can be any of the datatypes CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB.

• CANONICAL causes canonical decomposition, which allows recomposition (for example, with the COMPOSE function) to the original string. This is the default.

• COMPATIBILITY causes decomposition in compatibility mode. In this mode, recomposition is not possible. This mode is useful, for example, when decomposing half-width and full-width katakana characters, where recomposition might not be desirable without external formatting or style information.

CLOB and NCLOB values are supported through implicit conversion. If char is a character LOB value, it is converted to a VARCHAR value before the COMPOSE operation. The operation will fail if the size of the LOB value exceeds the supported length of the VARCHAR in the particular development environment.

See Also:

Oracle Database Globalization Support Guide for information on Unicode character sets and character semantics

Examples

The following example ss the string 'Châteaux' into its component code points:

Note:

The results of this example can vary depending on the character set of your operating system.

Description

Decompose a time series into seasonal, trend and irregular components using moving averages. Deals with additive or multiplicative seasonal component.

Usage

Arguments

A time series.

The type of seasonal component. Can be abbreviated.

A vector of filter coefficients in reverse time order (as for AR or MA coefficients), used for filtering out the seasonal component. If NULL, a moving average with symmetric window is performed.

Decomposed Body

Value

An object of class 'decomposed.ts' with following components:

Decompose Numbers

x

The original series.

seasonal

The seasonal component (i.e., the repeated seasonal figure).

figure

The estimated seasonal figure only.

trend

The trend component.

random

The remainder part.

Decompose

type

The value of type.

Decompose Defined

Details

The additive model used is: $$Y_t = T_t + S_t + e_t$$ The multiplicative model used is: $$Y_t = T_t,S_t, e_t$$

The function first determines the trend component using a moving average (if filter is NULL, a symmetric window with equal weights is used), and removes it from the time series. Then, the seasonal figure is computed by averaging, for each time unit, over all periods. The seasonal figure is then centered. Finally, the error component is determined by removing trend and seasonal figure (recycled as needed) from the original time series.

This only works well if x covers an integer number of complete periods.

References

M. Kendall and A. Stuart (1983) The Advanced Theory of Statistics, Vol.3, Griffin. pp.410--414.

Decompose Etymology

See Also

Examples