R Programming Week 2 HW

dat<-mtcars
head(dat)

##                    mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
## Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

Answer

Independent Variable: Type of Cylinder
Dependent Variable: Gas Mileage (mpg)

There are 11 features in total.

str(mtcars)

## 'data.frame':    32 obs. of  11 variables:
##  $ mpg : num  21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
##  $ cyl : num  6 6 4 6 8 6 8 4 4 6 ...
##  $ disp: num  160 160 108 258 360 ...
##  $ hp  : num  110 110 93 110 175 105 245 62 95 123 ...
##  $ drat: num  3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
##  $ wt  : num  2.62 2.88 2.32 3.21 3.44 ...
##  $ qsec: num  16.5 17 18.6 19.4 17 ...
##  $ vs  : num  0 0 1 1 0 1 0 1 1 1 ...
##  $ am  : num  1 1 1 0 0 0 0 0 0 0 ...
##  $ gear: num  4 4 4 3 3 3 3 4 4 4 ...
##  $ carb: num  4 4 1 1 2 1 4 2 2 4 ...

dat<-iris 
head(dat)

##   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1          5.1         3.5          1.4         0.2  setosa
## 2          4.9         3.0          1.4         0.2  setosa
## 3          4.7         3.2          1.3         0.2  setosa
## 4          4.6         3.1          1.5         0.2  setosa
## 5          5.0         3.6          1.4         0.2  setosa
## 6          5.4         3.9          1.7         0.4  setosa

Answer

Independent Variable: Sepal Length, Sepal Width, Petal Length, and Petal Width
Dependent Variable: The species of the Iris

dat<-iris
head(iris,10)

##    Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1           5.1         3.5          1.4         0.2  setosa
## 2           4.9         3.0          1.4         0.2  setosa
## 3           4.7         3.2          1.3         0.2  setosa
## 4           4.6         3.1          1.5         0.2  setosa
## 5           5.0         3.6          1.4         0.2  setosa
## 6           5.4         3.9          1.7         0.4  setosa
## 7           4.6         3.4          1.4         0.3  setosa
## 8           5.0         3.4          1.5         0.2  setosa
## 9           4.4         2.9          1.4         0.2  setosa
## 10          4.9         3.1          1.5         0.1  setosa

?iris
unique_species<-unique(dat$Species)
print(unique_species)

## [1] setosa     versicolor virginica 
## Levels: setosa versicolor virginica

library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

dat %>%
  group_by(Species) %>%
  summarize (AVG=mean(Sepal.Length, na.rm=T),
             SD=sd(Sepal.Length, na.rm=T),
             Median=median(Sepal.Length, na.rm=T))

## # A tibble: 3 × 4
##   Species      AVG    SD Median
##   <fct>      <dbl> <dbl>  <dbl>
## 1 setosa      5.01 0.352    5  
## 2 versicolor  5.94 0.516    5.9
## 3 virginica   6.59 0.636    6.5

library(ggplot2)
dat %>%
  ggplot(aes(Species,Sepal.Length))+
  geom_boxplot()

Analysis

The data table in Figure 1 shows that Virginica has the highest average and median, indicating that the species has the greatest sepal length. However, its standard deviation is also the highest, portraying that the data of the species Virginia is more spread out than the Setosa and the Vericolor. The box plot also shows similar results, with the Setosa being the species with the shortest Sepal Length while the data sets are situated closer to the mean, seen by the small difference in the interquartile range of the data. The box plot of Virginica, in contrast, have a higher interquatile range than the other species, indicating that the data are spread over a wider range. The diagram signifies that Virgnicia has the greatest Sepal Length, however, as seen by the box plot that is situated higher than the Setosa and the Versicolor.

R Programming Week 2 HW

2024-04-13

Answer

Answer

Analysis