Poster Number 174
See more from this Division: Topical Sessions
See more from this Session: Soil Geochemistry: Databases and Applications at Regional to Continental Scales (Posters)
Abstract:
Average level is best estimated by the median, a robust measure of central location that is uninfluenced by up to 50% extreme values. However, the average level tells only part of the story. If a question such as, is a value background? is to be answered it immediately follows that the range of background has to be known. The estimation of background range is a task that requires the integration of graphical data inspection, the calculation of statistically based estimates, and geochemical knowledge. To support this activity a software package, rgr' has been prepared in the Open Source R language that displays the data in a variety of graphical formats familiar to applied geochemists, and computes a variety of estimates of background range based on non-parametric and traditional and robust parametric estimation procedures. A key display in helping visualize background ranges is the Tukey boxplot. The poster illustrates the various tools available within rgr' and discusses their relative merits.
See more from this Division: Topical Sessions
See more from this Session: Soil Geochemistry: Databases and Applications at Regional to Continental Scales (Posters)