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-rw-r--r--r.html.markdown23
1 files changed, 12 insertions, 11 deletions
diff --git a/r.html.markdown b/r.html.markdown
index 8539b10e..79af40ce 100644
--- a/r.html.markdown
+++ b/r.html.markdown
@@ -192,7 +192,7 @@ class(-Inf) # "numeric"
2.0 * 2L # 4 # numeric times integer gives numeric
3L / 4 # 0.75 # integer over numeric gives numeric
3 %% 2 # 1 # the remainder of two numerics is another numeric
-# Illegal arithmetic yeilds you a "not-a-number":
+# Illegal arithmetic yields you a "not-a-number":
0 / 0 # NaN
class(NaN) # "numeric"
# You can do arithmetic on two vectors with length greater than 1,
@@ -255,16 +255,16 @@ c('Z', 'o', 'r', 'r', 'o') == "Z" # TRUE FALSE FALSE FALSE FALSE
# FACTORS
# The factor class is for categorical data
-# Factors can be ordered (like childrens' grade levels) or unordered (like gender)
-factor(c("female", "female", "male", NA, "female"))
-# female female male <NA> female
-# Levels: female male
+# Factors can be ordered (like childrens' grade levels) or unordered (like colors)
+factor(c("blue", "blue", "green", NA, "blue"))
+# blue blue green <NA> blue
+# Levels: blue green
# The "levels" are the values the categorical data can take
# Note that missing data does not enter the levels
-levels(factor(c("male", "male", "female", NA, "female"))) # "female" "male"
+levels(factor(c("green", "green", "blue", NA, "blue"))) # "blue" "green"
# If a factor vector has length 1, its levels will have length 1, too
-length(factor("male")) # 1
-length(levels(factor("male"))) # 1
+length(factor("green")) # 1
+length(levels(factor("green"))) # 1
# Factors are commonly seen in data frames, a data structure we will cover later
data(infert) # "Infertility after Spontaneous and Induced Abortion"
levels(infert$education) # "0-5yrs" "6-11yrs" "12+ yrs"
@@ -662,8 +662,9 @@ require(plyr)
#########################
# "pets.csv" is a file on the internet
-# (but it could just as easily be be a file on your own computer)
-pets <- read.csv("http://learnxinyminutes.com/docs/pets.csv")
+# (but it could just as easily be a file on your own computer)
+require(RCurl)
+pets <- read.csv(textConnection(getURL("https://learnxinyminutes.com/docs/pets.csv")))
pets
head(pets, 2) # first two rows
tail(pets, 1) # last row
@@ -788,7 +789,7 @@ install.packages("ggplot2")
require(ggplot2)
?ggplot2
pp <- ggplot(students, aes(x=house))
-pp + geom_histogram()
+pp + geom_bar()
ll <- as.data.table(list1)
pp <- ggplot(ll, aes(x=time,price))
pp + geom_point()