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Preface to First Edition - lib

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SUMMARY 311ExercisesEx. 17.1 The data in Table 17.3 shows road distances between 21 Europeancities. Apply classical scaling <strong>to</strong> the matrix and compare the plotted twodimensionalsolution with a map of Europe.Ex. 17.2 In Table 17.4 (from Kaufman and Rousseeuw, 1990), the dissimilaritymatrix of 18 species of garden flowers is shown. Use some form ofmultidimensional scaling <strong>to</strong> investigate which species share common properties.Ex. 17.3 Consider 51 objects O 1 , ...,O 51 assumed <strong>to</strong> be arranged along astraight line with the jth object being located at a point with coordinatej. Define the similarity s ij between object i and object j as⎧9 if i = j8 if 1 ≤ |i − j| ≤ 3⎪⎨7 if 4 ≤ |i − j| ≤ 6s ij =· · ·1 if 22 ≤ |i − j| ≤ 24⎪⎩0 if |i − j| ≥ 25Convert these similarities in<strong>to</strong> dissimilarities (δ ij ) by usingδ ij = √ s ii + s jj − 2s ijand then apply classical multidimensional scaling <strong>to</strong> the resulting dissimilaritiymatrix. Explain the shape of the derived two-dimensional solution.© 2010 by Taylor and Francis Group, LLC

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