Homework1.R

Julia — Sep 21, 2013, 8:45 PM

#Julia Wei
#Homework Chapter 1
#PH 251D
#09.21.2013

#1.1. The R workspace on my computer is .RData. The computer file path to the workspace file is obtained using the getwd function. 
getwd()
[1] "C:/Users/Julia/Documents"

#1.2. By default, the R packages that come already loaded is found through search ().
search()
 [1] ".GlobalEnv"        "package:knitr"     "package:stats"    
 [4] "package:graphics"  "package:grDevices" "package:utils"    
 [7] "package:datasets"  "package:methods"   "Autoloads"        
[10] "package:base"     
#The File paths to the default R packages are found through the searchpaths function.
searchpaths()
 [1] ".GlobalEnv"                                      
 [2] "C:/Users/Julia/Documents/R/win-library/3.0/knitr"
 [3] "C:/Program Files/R/R-3.0.1/library/stats"        
 [4] "C:/Program Files/R/R-3.0.1/library/graphics"     
 [5] "C:/Program Files/R/R-3.0.1/library/grDevices"    
 [6] "C:/Program Files/R/R-3.0.1/library/utils"        
 [7] "C:/Program Files/R/R-3.0.1/library/datasets"     
 [8] "C:/Program Files/R/R-3.0.1/library/methods"      
 [9] "Autoloads"                                       
[10] "C:/PROGRA~1/R/R-30~1.1/library/base"             

#1.3. The objects in the current workspace are obtained through ls(). 
ls()
character(0)
x <- c(1,2,3,4,5)
gender <- c("boy", "boy", "girl")
ls()
[1] "gender" "x"     
rm(list = ls())
ls()
character(0)

#1.4.
inches <- 1:12
centimeters <- inches*2.54
cbind(inches, centimeters)
      inches centimeters
 [1,]      1        2.54
 [2,]      2        5.08
 [3,]      3        7.62
 [4,]      4       10.16
 [5,]      5       12.70
 [6,]      6       15.24
 [7,]      7       17.78
 [8,]      8       20.32
 [9,]      9       22.86
[10,]     10       25.40
[11,]     11       27.94
[12,]     12       30.48

#1.5.
celsius <- c(0,100)
fahrenheit <- ((9/5)*celsius) +32
fahrenheit
[1]  32 212

#1.6.
celsius <- seq(0, 100, 5)
fahrenheit <- ((9/5)*celsius) + 32
cbind(celsius, fahrenheit)
      celsius fahrenheit
 [1,]       0         32
 [2,]       5         41
 [3,]      10         50
 [4,]      15         59
 [5,]      20         68
 [6,]      25         77
 [7,]      30         86
 [8,]      35         95
 [9,]      40        104
[10,]      45        113
[11,]      50        122
[12,]      55        131
[13,]      60        140
[14,]      65        149
[15,]      70        158
[16,]      75        167
[17,]      80        176
[18,]      85        185
[19,]      90        194
[20,]      95        203
[21,]     100        212

#1.7.
JWkg <- 120/2.2
JWm <- 5/3.3
BMI <- JWkg/(JWm^2)
BMI
[1] 23.76

#1.8.Integer divide is when you do division and discard the remainder. Modulus is the remainder you get when you divide one number by another.
10%/%3
[1] 3
10%%3
[1] 1

#1.9.
curve(log(x), 0, 6)
abline(v = c(1, exp(1)), h = c(0,1), lty = 2)

plot of chunk unnamed-chunk-1


#1.10.
curve(x/(1-x), 0, 1)

plot of chunk unnamed-chunk-1

curve(log(x/(1-x)), 0, 1)

plot of chunk unnamed-chunk-1


#1.11.
n <- 365
risk.per.ten.thousand.exposures <- c(67, 50, 30, 10, 6.5, 5, 1, 0.5)
risk.per.act <- c((risk.per.ten.thousand.exposures)/10000)
risk <- 1-(1-risk.per.act)^n
acts <- c("IDU", "RAI", "PNS", "RPVI", "IAI", "IPVI", "ROI", "IOI")
names(risk) <- acts
risk
    IDU     RAI     PNS    RPVI     IAI    IPVI     ROI     IOI 
0.91403 0.83952 0.66601 0.30593 0.21127 0.16685 0.03584 0.01808 

#1.12.?
source("/Users/Julia/Documents/HW1job01.R")
source("/Users/Julia/Documents/HW1job01.R", echo = TRUE)

> n <- 365

> risk.per.ten.thousand.exposures <- c(67, 50, 30, 10, 
+     6.5, 5, 1, 0.5)

> risk.per.act <- c((risk.per.ten.thousand.exposures)/10000)

> risk <- 1 - (1 - risk.per.act)^n

> acts <- c("IDU", "RAI", "PNS", "RPVI", "IAI", "IPVI", 
+     "ROI", "IOI")

> names(risk) <- acts

> risk
    IDU     RAI     PNS    RPVI     IAI    IPVI     ROI     IOI 
0.91403 0.83952 0.66601 0.30593 0.21127 0.16685 0.03584 0.01808 

#1.13.?
sink("/Users/Julia/Documents/HW1job01.log1a")
source("/Users/Julia/Documents/HW1job01.R")
sink() 

sink("/Users/Julia/Documents/HW1job01.log1b")
source("/Users/Julia/Documents/HW1job01.R", echo = TRUE)

> n <- 365

> risk.per.ten.thousand.exposures <- c(67, 50, 30, 10, 
+     6.5, 5, 1, 0.5)

> risk.per.act <- c((risk.per.ten.thousand.exposures)/10000)

> risk <- 1 - (1 - risk.per.act)^n

> acts <- c("IDU", "RAI", "PNS", "RPVI", "IAI", "IPVI", 
+     "ROI", "IOI")

> names(risk) <- acts

> risk
    IDU     RAI     PNS    RPVI     IAI    IPVI     ROI     IOI 
0.91403 0.83952 0.66601 0.30593 0.21127 0.16685 0.03584 0.01808 
sink()

#HW1job01.log1a is empty while HW1job01.log1b has a copy of what is in HW1job01.R

#1.14.
source("/Users/Julia/Documents/HW1job02.R")
[1] 0.01808 0.03584 0.16685 0.21127 0.30593 0.66601 0.83952 0.91403
#what is shown is the what is within the show() function in the other file.