Publications by Magnus Skonberg
DATA 605 HW2
PROBLEM SET 1 (1) Show that AT A does not equal A AT in general. (Proof and demonstration.) Per course text, matrix multiplication is not commutative and thus the order of the operands affects the result of the equation. Proof: If we take a 2x2 matrix, A = [a11 a12], [a21, a22] AT = [b11, b12], [b21, b22] AAT = (a11b11 + a12b21) (a11b12 + a12b22)...
1797 sym R (2007 sym/11 pcs)
RBridge_Wk3_Assignment
###Start of assignment### library(ggplot2) #load ggplot library setwd(“C:/Users/magnu/Documents/R”) #set the working directory IMPORT THE DATA nukedata <- read.csv(“nuclear.csv”) #import Nuclear power station construction data summary(nukedata) #explore data characteristics #Initial data conclusions: #(1) ‘cost’: cost of construction...
2894 sym
RBridge_Wk1_Assignment
#Accepted CUNY admission last week and was granted bridge course access yesterday (7/21/2020). I will review course material and complete assignments on my own to better prepare for the start of the MSDS program late in August. ###Start of Assignment### #1. Write a loop that calculates 12-factorial i <- 1 sum <- 1 for (i in 1:12) { sum <- sum * i...
997 sym
DATA 605 HW1
PROBLEM SET 1 (1) Calculate the dot product u.v where u = [0.5; 0.5] and v = [3; −4] Multiply corresponding elements of each vector. u <- c(0.5, 0.5) v <- c(3, -4) u.v <- sum(u*v) u.v ## [1] -0.5 (2) What are the lengths of u and v? Please note that the mathematical notion of the length of a vector is not the same as a computer science defin...
796 sym R (1391 sym/12 pcs)
DATA 606 Presentation
Exercise 1.1 (p. 11) Migraine and acupuncture, Part I. A migraine is a particularly painful type of headache, which patients sometimes wish to treat with acupuncture. To determine whether acupuncture relieves migraine pain, researchers conducted a randomized controlled study where 89 females diagnosed with migraine headaches were randomly assig...
2756 sym R (537 sym/7 pcs)
DATA 607 Week2 Assignment
OVERVIEW The purpose of this assignment was to collect data, store it in a relational (SQL) database, and then import this data into an R dataframe to analyze it. I polled (6) immediate family members and/or significant others regarding (5) movies that had come out in the past year, asked for their rating, from 1 to 5, and stored their response o...
2212 sym R (3360 sym/11 pcs) 1 img
DATA 607 Week1 Assignment
Purpose To load and transform a dataset using R. Article Overview Pollsters have been busy fielding surveys to measure concern levels since the first known case of COVID-19 was reported to the CDC back in January. They’ve polled respondents on the government’s handling of the infection, concern levels regarding the infection, and concern l...
1397 sym R (589 sym/3 pcs) 1 img
RBridge_Wk2_Assignment
###Start of Assignment### #1. Use the summary function to gain an overview of the data set. Then display the mean and median for at least two attributes. #set the working directory setwd(“C:/Users/magnu/Documents/R”) #import the data and look at the first 6 rows mydata <- read.csv(“bigcity.csv”) #display summary of dataset summary(mydata)...
2367 sym
DATA 607 Project 3
Code Show All Hide All DATA 607 - Project 3 BACKGROUND DATA SOURCE(S) APPROACH ACQUIRE DATA TIDY & TRANSFORM SURVEY QUESTIONS & ANSWERS SURVEY SOFTWARE SKILLS SURVEY GENERAL SKILLS SURVEY VALUE FILTER JOB BOARD SKILLS VISUALIZE & ANALYZE CONCLUDE NOTE FROM THE TEAM Team Silver Fox 2020-10-17 BACKGROUND What are the most valued data sci...
16467 sym R (13774 sym/26 pcs) 6 img
DATA 605 HW8
Background The purpose of this assignment is to explore the application and properties of the Sum of Random Variables and Law of Large Numbers. (1) Ch 7 Ex 11 (p 303) A company buys 100 lightbulbs, each of which has an exponential lifetime of 1000 hours. What is the expected time for the first of these bulbs to burn out? (See Exercise 10.) We de...
1960 sym R (1209 sym/10 pcs)