1,721,245 research outputs found
La statistica e gli aneurismi: il logaritmo che può salvare la vita
No full textArticolo su rivista divulgativa: Newton RC
Il Problema della Classificazione Statistica e i CART: Teoria e Applicazioni(Statistical Classification and CART: Theory and Applications)
No full textTesi di Laure
Functional Data Analysis of the Geometrical Features of the Internal Carotid Artery
No full textPhD Thesi
On the Definition of Phase and Amplitude Variability in Functional Data Analysis
No full textWe introduce a modeling and mathematical framework in which the problem of registering a functional data set can be consistently set. In detail, we show that the introduction, in a functional data analysis, of a metric/semi-metric and of a group of warping functions, with respect to which the metric/semi-metric is invariant, enables a sound and not ambiguous definition of phase and amplitude variability. Indeed, in this framework, we prove that the analysis of a registered functional data set can be re-interpreted as the analysis of a set of suitable equivalence classes associated to original functions and induced by the group of the warping functions. Moreover, an amplitude-to-total variability index is proposed. This index turns out to be useful in practical situations for measuring to what extent phase variability affects the data and for comparing the effectiveness of different registration methods
Wishing the Non-parametric Re-evolution
No full textThis short paper presents some personal considerations on the challenge that the outbreak of big data (which I prefer to call complex data) has posed to statistics as a discipline. I also unpretentiously indicate a possible (hopefully winning) strategy to tackle this challenge
The interval testing procedure: a general framework for inference in functional data analysis
No full textWe introduce in this work the Interval Testing Procedure (ITP), a novel inferential technique for functional data. The procedure can be used to test different functional hypotheses, e.g., distributional equality between two or more functional populations, equality of mean function of a functional population to a reference. ITP involves three steps: (i) the representation of data on a (possibly high-dimensional) functional basis; (ii) the test of each possible set of consecutive basis coefficients; (iii) the computation of the adjusted p-values associated to each basis component, by means of a new strategy here proposed. We define a new type of error control, the interval-wise control of the family wise error rate, particularly suited for functional data. We show that ITP is provided with such a control. A simulation study comparing ITP with other testing procedures is reported. ITP is then applied to the analysis of hemodynamical features involved with cerebral aneurysm pathology. ITP is implemented in the fdatest R package
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