Statistics seminar
Liverpool University Statistics Division
Time: 2pm, Wednesday May 26th
Venue: Room 6.04, Maths & Oceanography Building, University of Liverpool
Speaker: Helen Wilson, University of Liverpool
Title: A comparison of a parametric and a non-parametric approach to the
assessment of replicated spatial point patterns
Abstract: The basic methodology for analysing spatial point pattern data is
now well established (Cressie (1993), Diggle (1983), Ripley (1981)). For the
single replicate point patterns which dominate the spatial point pattern
literature, there has been a strong emphasis on fitting parametric models.
The fields of pathology and materials science, however, present us with
numerous opportunities for collecting replicated spatial point pattern data.
As an example, we can easily digitise the positions of cells within multiple
windows imposed upon brain tissue, using only standard microscopical
equipment.
In our work, we exploit replication of this nature, and develop a parametric
and a non-parametric approach to the assessment of replicated spatial point
patterns. We begin by proposing a non-parametric method, motivated by analysis
of variance, which uses the replication as the basis for inference.
Subsequently, we suggest a parametric, maximum pseudo-likelihood based
approach to the same problem.
Specifically, we address the following questions:
When we specify the correct model for a given data set, is the parametric
approach more powerful than the non-parametric approach?
When the model specification is incorrect, does the parametric approach give
misleading results?
This is joint work with Peter Diggle (University of Lancaster, U.K.) and Jorge
Mateu (Universitat Jaume I, E-12071 Castellón, Spain). Microscopy was carried
out with Dr. Vyvyan Howard (University of Liverpool, U.K.)
Other forthcoming seminars:
Friday 4 June
Clive Anderson (University of Sheffield)
Tuesday 21 September
Alexandros Karagregoriou (University of Cyprus)
On asymptotic properties of model identification procedures
Full seminar programme available via http://www.liv.ac.uk/maths/SOR/
Damian Clancy
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