Publications by Marley Myrianthopoulos
Data 605 Discussion 4
Page 349 Problem #C25 Define the linear transformation \(T:\mathbb{C}^3\rightarrow\mathbb{C}^2,\quad T\left(\begin{bmatrix}x_1\\x_2\\x_3\end{bmatrix}\right)=\begin{bmatrix}2x_1-x_2+5x_3\\-4x_1+2x_2-10x_3\end{bmatrix}\) Verify that \(T\) is a linear transformation. Solution The two conditions of a linear transformation are \(T(x+y)=T(x)+T(y)\) (i...
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Data 605 Discussion 3
Page 306 Problem #C22 “Without using a calculator, find the eigenvalues of the matrix \(B\).” \(B=\begin{bmatrix}2 & -1\\1 & 1\end{bmatrix}\) Solution \(det(\begin{bmatrix}2 & -1\\1 & 1\end{bmatrix}-\begin{bmatrix}\lambda & 0\\0 & \lambda\end{bmatrix})=0\) \(det(\begin{bmatrix}2-\lambda & -1\\1 & 1-\lambda\end{bmatrix})=0\) \([(2-\lambda)(1-...
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Data 605 Discussion 1
Page 14 Problem #C50 “A three-digit number has two properties. The tens-digit and the ones-digit add up to 5. If the number is written with the digits in the reverse order, and then subtracted from the original number, the result is 792. Use a system of equations to find all of the three digit numbers with these properties.” Solution This syst...
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Data 605 Discussion 2
Page 278 Problem #M11 “Find a value of \(k\) so that the matrix \(A=\begin{bmatrix} 1 & 2 & 1\\2 & 0 & 1\\2 & 3 & k\end{bmatrix}\) has det\((A)=0\), or explain why this is not possible.” Solution det\((A)=1\begin{vmatrix}0 & 1\\3 & k\end{vmatrix}-2\begin{vmatrix}2 & 1\\2 & k\end{vmatrix}+1\begin{vmatrix}2 & 0\\2 & 3\end{vmatrix}\\=1((0)(k)-(1)...
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data607week9assignment
Overview In this assignment, I use the New York Times API to import and analyze the JSON of stories on their home page. Importing Data In this code block, I load the necessary libraries and import the JSON data. library(jsonlite) library(tidyr) library(dplyr) ## ## Attaching package: 'dplyr' ## The following objects are masked from 'package:stats...
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DATA 607 Assignment 7
Overview For this assignment, I created an HTML file, a JSON file, and an XML file that contain information on three of my favorite books and stored them in my github repository. The task is to load this information into three separate R data frames. HTML In this code block, I import the html table from my github repository and use the convenient ...
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DATA 607 Project 2 Part 1
Overview This is the first part of my Project 2 assignment for DATA607 in the Fall 2023 Term at CUNY SPS. In this assignment I import a wide data set, tidy it, and then analyze it. I created this first data set, which contains the seasonal home run totals for the starting player from each position for each team in the American League Eastern Divisi...
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DATA 607 Project 2 Part 3
Overview This is the third part of my Project 2 assignment for DATA607 in the Fall 2023 Term at CUNY SPS. In this assignment I import a wide data set, tidy it, and then analyze it. This third data set contains data for a work order process at a manufacturing site. Tidying Data In this code block, I load the necessary libraries and import the data ...
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DATA 607 Project 2 Part 2
Overview This is the second part of my Project 2 assignment for DATA607 in the Fall 2023 Term at CUNY SPS. In this assignment I import a wide data set, tidy it, and then analyze it. This second data set contains the distribution of doctoral degrees from US universities every 5 years from 1992 to 2022. Tidying Data In this code block, I load the ne...
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DATA 607 Assignment 5
Overview In this assignment, I use tidyverse to “tidy” a data set using pivot_longer, add some summary statistics, and then use pivot_wider to create a new comparison table to look at flight delay rates from two airlines to five airports. Importing Data In this code block, I import the original “wide” .csv file from my github repository in...
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