Sampling variogram

In mathematical statistics, a sampling variogram is a graph that shows where a significant degree of causality (in this context, spatial dependence in sample spaces or sampling units) dissipates into randomness. A sampling variogram is obtained by plotting statisticallly significant variance terms of a temporally or "in situ" ordered set of measured values against the variance of the set and the lower limits of its asymmetric 95% and 99% confidence ranges. Corrected sampling variograms derive from uncorrected ones when extraneous measurement variances are subtracted before spatial dependence is verified. Bre-X's bogus gold grades for crushed, salted and "in situ" ordered core samples of Borehole BSSE198 in Busang's South-East zone give the following uncorrected sampling variogram.


-->

[http://www.geostatscam.com/corrected_sampling_variogram.htm The corrected sampling variogram for Bre-X's bonanza borehole, its primary data set and test statistics are posted on this page.] A temporally ordered set of on-stream data for mill feed to a mineral processing plant, its test statistics and sampling variogram are given in [http://www.geostatscam.com/Excel/Appendix%20D.xls Appendix D] of "Sampling in Mineral Processing". A variogram or a semi-variogram, unlike the above sampling variogram, does not show where spatial dependence in sample spaces dissipates into randomness because kriging variances of sets of kriged estimates are invalid measures for variability, precision and risk.

References

# Armstrong, M and Champigny, N, 1988, A Study on Kriging Small Blocks, CIM Bulletin, Vol 82, No 923
# Clark, I, 1979, Practical Geostatistics, Applied Science Publishers, London
# David, M, 1977, Geostatistical Ore Reserve Estimation, Elsevier Scientific Publishing Company, Amsterdam
# Hald, A, 1952, Statistical Theory with Engineering Applications, John Wiley & Sons, New York
# ISO/DIS 11648, Statistical aspects of sampling from bulk materials, Part 1: General Principles
# Journel, A G and Huijbregts, C J, 1978, Mining Geostatistics, Academic Press Inc, London 1978
# Philip, G M and Watson, D F, 1986, Matheronian Geostatistics; Quo Vadis?, Mathematical Geology, Vol 18, No 1

External links

* [http://www.geostatscam.com This website explains how to design uncorrected and corrected sampling variograms, and how to verify where spatial dependence in sample spaces or sampling units dissipates into randomness]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Variogram — In spatial statistics the theoretical variogram 2γ(x,y) is a function describing the degree of spatial dependence of a spatial random field or stochastic process Z(x). It is defined as the variance of the difference between field values at two… …   Wikipedia

  • Kriging — is a group of geostatistical techniques to interpolate the value of a random field (e.g., the elevation, z , of the landscape as a function of the geographic location) at an unobserved location from observations of its value at nearby locations.… …   Wikipedia

  • List of statistics topics — Please add any Wikipedia articles related to statistics that are not already on this list.The Related changes link in the margin of this page (below search) leads to a list of the most recent changes to the articles listed below. To see the most… …   Wikipedia

  • Semivariance — In spatial statistics, the empirical semivariance is described by:hatgamma(h)=frac{1}{2}cdotfrac{1}{n(h)}sum {i=1}^{n(h)}(z(x i+h) z(x i))^2where z is a datum at a particular location, h is the distance between ordered data, and n ( h ) is the… …   Wikipedia

  • Spatial dependence — In mathematical statistics, spatial dependence is a measure for the degree of associative dependence between independently measured values in a temporally or in situ ordered set, determined in samples selected at positions with different… …   Wikipedia

  • List of mathematics articles (S) — NOTOC S S duality S matrix S plane S transform S unit S.O.S. Mathematics SA subgroup Saccheri quadrilateral Sacks spiral Sacred geometry Saddle node bifurcation Saddle point Saddle surface Sadleirian Professor of Pure Mathematics Safe prime Safe… …   Wikipedia

  • Bre-X — Minerals Ltd., a member of the Bre X group of companies, was a junior Canadian mining company, based in Calgary, that was once reported to be sitting on an enormous gold deposit at Busang, Indonesia (on Borneo). Bre X bought the Busang site in… …   Wikipedia

  • Lag (disambiguation) — Lag refers to delays experienced in computing and communications.Lag may also refer to:* A measure for spatial dependence in a sampling variogram *Lag (cue sports), brief pre game competition to determine which player will break the rack *Lagging …   Wikipedia

  • Glossaire du data mining — Exploration de données Articles principaux Exploration de données Fouille de données spatiales Fouille du web Fouille de flots de données Fouille de textes …   Wikipédia en Français

  • Allan variance — The Allan variance, named after David W. Allan, is a measurement of stability in clocks and oscillators. It is also known as the two sample variance.It is defined as one half of the time average of the squares of the differences between… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.