target distribution
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target distribution
Hai,
Hieronder vind je een stukje over MaxEnt modelling van species' distribution gebaseerd op maximum entropy:
Context:
The idea of Maxent is to estimate a target probability distribution by finding the probability distribution of maximum entropy (i.e., that is most spread out, or closest to uniform), subject to a set of constraints that represent our incomplete information about the target distribution. The information available about the target distribution often presents itself as a set of real-valued variables, called “features”, and the constraints are that the expected value of each feature should match its empirical average (average value for a set of sample points taken from the target distribution). When Maxent is applied to presence-only species distribution modeling, the pixels of the study area make up the space on which the Maxent probability distribution is defined, pixels with known species occurrence records constitute the sample points, and the features are climatic variables, elevation, soil category, vegetation type or other environmental variables, and functions thereof.
Mijn vraag: waarom hebben ze het over 'target distribution', en niet gewoon over 'distribution'? Voegt het iets (limiterend qua betekenis) toe aan het begrip door 'target' toe te voegen?
Hieronder vind je een stukje over MaxEnt modelling van species' distribution gebaseerd op maximum entropy:
Context:
The idea of Maxent is to estimate a target probability distribution by finding the probability distribution of maximum entropy (i.e., that is most spread out, or closest to uniform), subject to a set of constraints that represent our incomplete information about the target distribution. The information available about the target distribution often presents itself as a set of real-valued variables, called “features”, and the constraints are that the expected value of each feature should match its empirical average (average value for a set of sample points taken from the target distribution). When Maxent is applied to presence-only species distribution modeling, the pixels of the study area make up the space on which the Maxent probability distribution is defined, pixels with known species occurrence records constitute the sample points, and the features are climatic variables, elevation, soil category, vegetation type or other environmental variables, and functions thereof.
Mijn vraag: waarom hebben ze het over 'target distribution', en niet gewoon over 'distribution'? Voegt het iets (limiterend qua betekenis) toe aan het begrip door 'target' toe te voegen?
- Berichten: 6.853
Re: target distribution
Volgens mij is dit alleen maar omdat de maximale-entropiemethode één distributie vindt uit de hele groep die aan alle constraints voldoet. Die ene is het "doel" dat wordt bereikt door de maximalisering van de entropie.