Semivariance - en.LinkFang.org

Semivariance


For the measure of downside risk, see Variance#Semivariance

In spatial statistics, the empirical semivariance is described by semivariance,\({\displaystyle \gamma (h)={\dfrac {1}{2n(h)}}\sum _{i=1}^{n(h)}[z(x_{i}+h)-z(x_{i})]^{2}}\)where z is the attribute value

where z is a datum at a particular location, h is the distance between ordered data, and n(h) is the number of paired data at a distance of h. The semivariance is half the variance of the increments \({\displaystyle z(x_{i}+h)-z(x_{i})}\), but the whole variance of z-values at given separation distance h (Bachmaier and Backes, 2008).

A plot of semivariances versus distances between ordered data in a graph is known as a semivariogram rather than a variogram. Many authors call \({\displaystyle 2{\hat {\gamma }}(h)}\) a variogram, others use the terms variogram and semivariogram synonymously. However, Bachmaier and Backes (2008), who discussed this confusion, have shown that \({\displaystyle {\hat {\gamma }}(h)}\) should be called a variogram, terms like semivariogram or semivariance should be avoided.

See also


References


External links













Categories: Geostatistics | Statistical deviation and dispersion | Statistics stubs




Information as of: 10.06.2020 07:11:35 CEST

Source: Wikipedia (Authors [History])    License : CC-by-sa-3.0

Changes: All pictures and most design elements which are related to those, were removed. Some Icons were replaced by FontAwesome-Icons. Some templates were removed (like “article needs expansion) or assigned (like “hatnotes”). CSS classes were either removed or harmonized.
Wikipedia specific links which do not lead to an article or category (like “Redlinks”, “links to the edit page”, “links to portals”) were removed. Every external link has an additional FontAwesome-Icon. Beside some small changes of design, media-container, maps, navigation-boxes, spoken versions and Geo-microformats were removed.

Please note: Because the given content is automatically taken from Wikipedia at the given point of time, a manual verification was and is not possible. Therefore LinkFang.org does not guarantee the accuracy and actuality of the acquired content. If there is an Information which is wrong at the moment or has an inaccurate display please feel free to contact us: email.
See also: Legal Notice & Privacy policy.