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When all types in the dataset of interest are equally common, all p i values equal 1 / R, and the Shannon index hence takes the value ln(R). The more unequal the abundances of the types, the larger the weighted geometric mean of the p i values, and the smaller the corresponding Shannon entropy. If practically all abundance is concentrated to ...
The Shannon index is the most commonly used way to quantitatively determine species diversity, H, as modeled by the following equation: = = The Shannon index factors in both species evenness and species richness, as represented by the variables p i and s, respectively. The lowest possible value of H is zero, and the higher a community’s H ...
There are many ways to measure biodiversity within a given ecosystem. However, the two most popular are Shannon-Weaver diversity index, [4] commonly referred to as Shannon diversity index, and the other is Simpsons diversity index. [5] Although many scientists prefer to use Shannon's diversity index simply because it takes into account species ...
The concept of information entropy was introduced by Claude Shannon in his 1948 paper "A Mathematical Theory of Communication", [2] [3] and is also referred to as Shannon entropy. Shannon's theory defines a data communication system composed of three elements: a source of data, a communication channel, and a receiver. The "fundamental problem ...
The source for this is a 1989 work by Charles J. Krebs. In a newer work, however (CJ Krebs. Ecology: the experimental analysis of distribution and abundance, 5th edition. p617-618), the same author calls the index the Shannon-Wiener index. Is there other information that could be used to find the "correct" name for the index, if one exists?
The Wiener index is named after Harry Wiener, who introduced it in 1947; at the time, Wiener called it the "path number". [2] It is the oldest topological index related to molecular branching. [ 3 ] Based on its success, many other topological indexes of chemical graphs, based on information in the distance matrix of the graph, have been ...
The Hosoya index is the first topological index recognized in chemical graph theory, and it is often referred to as "the" topological index. [6] Other examples include the Wiener index, Randić's molecular connectivity index, Balaban’s J index, [7] and the TAU descriptors.
In information theory, the conditional entropy quantifies the amount of information needed to describe the outcome of a random variable given that the value of another random variable is known. Here, information is measured in shannons , nats , or hartleys .