Publications by Chelsea Nowlin
Assignment 5 - STA 6543 UTSA
Q 2. For parts (a) through (c), indicate which of i. through iv. is correct. Justify your answer. (a) The lasso, relative to least squares, is: i. More flexible and hence will give improved prediction accuracy when its increase in bias is less than its decrease in variance. ii. More flexible and hence will give improved prediction accuracy when i...
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Assignment 8 - STA 6543 UTSA
Chapter 9, pg. 368 Q. 5 We have seen that we can fit an SVM with a non-linear kernel in order to perform classification using a non-linear decision boundary. We will now see that we can also obtain a non-linear decision boundary by performing logistic regression using non-linear transformations of the features. library(caret) ## Warning: package ...
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Assignment 6 - STA 6543 UTSA
Chapter 7 Q. 6 In this exercise, you will further analyze the Wage data set considered throughout this chapter. Perform polynomial regression to predict wage using age. Use cross-validation to select the optimal degree d for the polynomial. What degree was chosen, and how does this compare to the results of hypothesis testing using ANOVA? Make ...
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Assignment 7 - STA 6543 UTSA
Chapter 8 page 332 Exercise 3,8,9 Consider the Gini index, classification error, and entropy in a simple classification setting with two classes. Create a single plot that displays each of these quantities as a function of ˆpm1. The xaxis should display ˆpm1, ranging from 0 to 1, and the y-axis should display the value of the Gini index, class...
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Assignment 4 - STA 6543 UTSA
Q. 3 We now review k-fold cross-validation. Explain how k-fold cross-validation is implemented. k cross validation resamples and splits the observations into a number of groups that the data is to be split into with a single paramter (k) referencing the split groups. What are the advantages and disadvantages of k-fold cross-validation relative...
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Assignment 3 - STA 6543 UTSA
10.This question should be answered using the Weekly data set, which is part of the ISLR package. This data is similar in nature to the Smarket data from this chapter’s lab, except that it contains 1, 089 weekly returns for 21 years, from the beginning of 1990 to the end of 2010. Produce some numerical and graphical summaries of the Weekly dat...
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