Review Session 6 - École Polytechnique Fédérale de...

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Review Session 6 1

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Page 1: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

ReviewSession 6

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Page 2: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

The residuals for the red estimation are …

21 2 3 4 5

33%

0%0%

33%33%

1.

2.

3. log log 4. Noneoftheabove5. Idon’t know

Page 3: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

The residuals for the green estimation are …

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0% 0%0%

100%

0%

1.

2.

3. log log 4. Noneoftheabove5. Idon’t know

Page 4: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

If the error termsare not homoscedastic, itis better to …

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29%

14%14%

43%

1. Useℓ minimization rather than ℓ2. Rescale tomake theerror term

homoscedastic3. Useℓ minimization rather than ℓ4. Idonotknow

Page 5: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

We want to fit a data set  to a polynomial of degree 2:

.

Is this a linearregression model ? 

51 2 3

0%

13%

88%

1. Yes2. No3. Idon’t know

Page 6: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

The green estimation corresponds to assuming that the errorterms (blue dot  green curve) are iidlognormal.

61 2 3 4

33%

22%

33%

11%

1. True2. Almost true3. False4. Idon’t know

Page 7: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

Solution

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Page 8: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

The green estimation corresponds to assuming that the relative error terms(blue dot  green curve) are iid normal.

81 2 3 4

44%

0%

33%

22%

1. True2. Almost true3. False4. Idon’t know

Page 9: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

Solution

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Page 10: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

The   matrix for the model

has full rank.

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33%

11%11%

33%

11%

1. Yes2. No3. Itdependsonthe4. Itdependsonthe ′5. Idon’t know

Page 11: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

We fit the model 

using least squares. 

The obtained line is such that the average distance from the points to the line is 0.

111 2 3 4

22%

0%

22%

56%

1. True2. False3. Itdepends onthedata4. Idon’t know

Page 12: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

Solution

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Page 13: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

We fit the model 

using normminimization.

The obtained line leaves an equalnumber of points on each side

131 2 3 4

78%

0%0%

22%

1. True2. False3. Itdepends onthedata4. Idon’t know

Page 14: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

Solution

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Page 15: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

Find the parameter for each of thesestandard Pareto PDFs

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75%

0%0%0%

25%

1. 0.5; 1; 2; 32. 3; 2; 1; 0.53. 0.5; 2; 1; 34. 1; 2; 3; 0.55. Idon’t know

Page 16: Review Session 6 - École Polytechnique Fédérale de Lausanneperfeval.epfl.ch/printMe/review6s.pdf · Review Session 6 1. The residualsfor the red estimation are … 2 1 234 5 33%

The skewnessindices S1, S2 and the Kurtosisindices K1, K2 are…

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0% 0%

13% 13%

25%25%

0%

13%13%

1. S1>0,K1>0,S2>0,K2>02. S1<0,K1>0,S2>0,K2<03. S1>0,K1>0,S2=0,K2>04. S1<0,K1>0,S2=0,K2<05. S1>0,K1<0,S2>0,K2>06. S1<0,K1<0,S2>0,K2<07. S1>0,K1<0,S2=0,K2>08. S1>0,K1<0,S2=0,K2<09. Idon’t know