Publications by Don Padmaperuma
DATA 605 - Assignment 4
library(Matrix) library(matrixcalc) Problem Set 1 In this problem, we’ll verify using R that SVD and Eigenvalues are related. Given a 3 × 2 matrix A \[\mathbf{A} = \left[\begin{array} {rrr} 1 & 2 & 3 \\ -1 & 0 & 4 \end{array}\right] \] write code in R to compute \(X = AA^T\) and \(Y = A^TA\) Then, compute the eigenvalues and eigenvecto...
1234 sym R (3146 sym/32 pcs)
DPadmaperuma_Assignment2_PS2
Problem Set 2 Write an R function to factorize a square matrix A into LU or LDU, whichever you prefer. LU <- function(A){ # Check if matrix is square. if(dim(A)[1]!=dim(A)[2]){ return('STOP! Matrix is not square') } n <- nrow(A) #number of rows in A U <- A L <- diag(n) #assign diagonal to L for (j in c(1:n)){ ...
112 sym R (1383 sym/7 pcs)
DOE Data Task
library(kableExtra) library(stringr) library(tidyverse) ## -- Attaching packages ------------------------------------------------------------------------------- tidyverse 1.2.1 -- ## v ggplot2 3.2.1 v readr 1.3.1 ## v tibble 2.1.3 v purrr 0.3.2 ## v tidyr 0.8.3 v dplyr 0.8.3 ## v ggplot2 3.2.1 v forcats 0.4.0 ## -- C...
746 sym R (1173306 sym/26 pcs)
DATA 606 - Lab 9
Grading the professor Many college courses conclude by giving students the opportunity to evaluate the course and the instructor anonymously. However, the use of these student evaluations as an indicator of course quality and teaching effectiveness is often criticized because these measures may reflect the influence of non-teaching related charac...
13032 sym R (13226 sym/36 pcs) 11 img 1 tbl
DATA606_FinalExam
Part I Please put the answers for Part I next to the question number (2pts each): daysDrive is the only quantitative and descrete variable since it can be measured as well as a variable with posible values of only distinct points on sacale. mean = 3.3, median = 3.5 ; Since the distribution is left skewed, mean is smaller than the median. Also wi...
4693 sym R (6954 sym/67 pcs) 9 img
DATA 607 Week12 NOSQL migration
Introduction For this assignment, I take information from a relational database (MySQL) and migrate it to a NoSQL database (MongoDB). For the relational database I am using nycflights13 package. nycflights13 package has airline on-time data for all flights departing NYC in 2013. Also includes useful ‘metadata’ on airlines, airports, weather, ...
1540 sym R (8403 sym/35 pcs) 2 tbl
DATA 606 Final Project
Data Preparation library(tidyverse) ## -- Attaching packages ---------------------------------------------------------------------------------------------------------------------------------------- tidyverse 1.2.1 -- ## v ggplot2 3.2.1 v purrr 0.3.2 ## v tibble 2.1.3 v dplyr 0.8.3 ## v tidyr 0.8.3 v stringr 1.4.0 ## v readr ...
4757 sym R (35374 sym/72 pcs) 1 img 3 tbl
Tidyverse Assignment
Assignment For this assignment I am using Women World Cup 2019 Prediction data set that I retrieved from Fivethirtyeight site to create a programming sample “vignette” that demonstrate how to use few of the main capabilities of the selected tidyverse package. Introduction This dataset shows the chance that each team will win, lose or tie eve...
2392 sym R (7806 sym/23 pcs) 1 img
Final Project - UN Data
Data Preparation library(tidyverse) ## -- Attaching packages ---------------------------------------------------------------------------------------------------------------------------------------- tidyverse 1.2.1 -- ## v ggplot2 3.2.1 v purrr 0.3.2 ## v tibble 2.1.3 v dplyr 0.8.3 ## v tidyr 0.8.3 v stringr 1.4.0 ## v readr ...
2168 sym R (14550 sym/36 pcs) 1 tbl
DATA 607 - Tidyverse Assignment
Assignment For this assignment I am using Women World Cup 2019 Prediction data set that I retrieved from Fivethirtyeight site to create a programming sample “vignette” that demonstrate how to use few of the main capabilities of the selected tidyverse package. Introduction This dataset shows the chance that each team will win, lose or tie eve...
2392 sym R (7806 sym/23 pcs) 1 img