Publications by Ken Wood
Statistical Inference in R - Week 4 Quiz
baseline <- c(140,138,150,148,135) Week2 <- c(132,135,151,146,130) t.test(Week2,baseline,alternative="two.sided",paired=TRUE) ## ## Paired t-test ## ## data: Week2 and baseline ## t = -2.2616, df = 4, p-value = 0.08652 ## alternative hypothesis: true difference in means is not equal to 0 ## 95 percent confidence interval: ## -7.5739122 0.7...
5 sym R (1212 sym/12 pcs)
Statistical Inference in R Course Project - Part 1
Introduction In this project, we will investigate the exponential distribution in R and compare it with the Central Limit Theorem. The exponential distribution can be simulated in R with the expression rexp(n, lambda) where lambda is the rate parameter. The mean of the exponential distribution is 1/lambda and the standard deviation is also 1/lamb...
2071 sym R (720 sym/10 pcs) 2 img
Developing Data Products in R - Week 2 Project
Places Where I Have Lived Use a picture of me as the icon for each location… KenLatLong <- data.frame( lat = c(41.766667,41.716667,40.441944,42.295833,42.134064,42.083333,35.766667), lng = c(-71.45,-71.416667,-86.9125,-71.713333,-71.969017,-71.4,-78.633333)) KenLatLong %>% leaflet() %>% addTiles() %>% addMarkers(icon = KenPic, popup=...
85 sym R (472 sym/1 pcs)
Regression Models in R: Week 4 Quiz
Question #1 Consider the space shuttle data in the MASS library. Consider modeling the use of the autolander as the outcome (variable name use). Fit a logistic regression model with autolander (variable ‘auto’) use (labeled as “auto” 1) versus not (0) as predicted by wind sign (variable wind). Give the estimated odds ratio for autolander ...
2004 sym R (4832 sym/26 pcs)
Practical Machine Learning in R - Quiz 4
Clear out all previous R sessions… rm(list = ls()) Question 1 Load the vowel.train and vowel.test data sets: library(caret) ## Loading required package: lattice ## Loading required package: ggplot2 library(gbm) ## Loaded gbm 2.1.8 library(ElemStatLearn) data(vowel.train) data(vowel.test) Set the variable y to be a factor variable in both the t...
1960 sym R (4614 sym/51 pcs) 1 img
Data Science Capstone in R - Week 1 Quiz
Question 1 The en_US.blogs.txt file is how many megabytes? file.info("final/en_US/en_US.blogs.txt") ## size isdir mode mtime ## final/en_US/en_US.blogs.txt 210160014 FALSE 644 2014-07-22 05:13:05 ## ctime atime uid gid ## final/en_US/en_US.blog...
731 sym R (2660 sym/29 pcs)
Data Science Capstone in R - Week 2 Analysis
Instructions The goal of this project is to display that we’ve gotten used to working with the data and that we are on track to create your prediction algorithm. This report (to be submitted on R Pubs (http://rpubs.com/)) explains our exploratory analysis and our goals for the eventual app and algorithm. This document should be concise and expl...
3007 sym R (6124 sym/21 pcs)
Practical Machine Learning in R - Course Project
Background Using devices such as Jawbone Up, Nike FuelBand, and Fitbit it is now possible to collect a large amount of data about personal activity relatively inexpensively. These type of devices are part of the quantified self movement – a group of enthusiasts who take measurements about themselves regularly to improve their health, to find pa...
3685 sym R (6861 sym/31 pcs) 3 img
Practical Machine Learning in R - Quiz 3
Question 1 Load the cell segmentation data from the AppliedPredictiveModeling package using the commands: rm(list = ls()) library(AppliedPredictiveModeling) data(segmentationOriginal) library(caret) ## Loading required package: lattice ## Loading required package: ggplot2 Subset the data to a training set and testing set based on the Case varia...
2725 sym R (4287 sym/39 pcs) 2 img
Reproducible Research in R - Week 2 Assignment
Loading and preprocessing the data Show any code that is needed to: Load the data (i.e. read.csv()). Process/transform the data (if necessary) into a format suitable for your analysis. knitr::opts_chunk$set(echo = TRUE) library(chron) # Read in the data file. df <- read.csv("activity.csv") # Convert 'date' column to datetime variable. df$d...
2783 sym R (4371 sym/23 pcs) 4 img