title: “R Homework 3” author: “Gabby Krochmal” date: “Ecology Lab - Summer 2017” output: html_document: fig_caption: yes fig_height: 5 fig_width: 5 highlight: tango theme: default toc: yes toc_float: collapsed: no smooth_scroll: no pdf_document: fig_caption: yes fig_crop: no highlight: tango number_sections: no header-includes: - - geometry: margin=1in fontsize: 11pt —
# Loads the Iris Dataset! Answer the questions below.
# Edgar Anderson's Iris Data ####
# This famous (Fisher's or Anderson's) iris data set gives
# the measurements in centimeters of the sepal length,
# sepal width, petal length, and petal width for 50 flowers
# from three species of iris. The species are Iris setosa,
# Iris versicolor, and Iris virginica.
data("iris") # Loads "iris" data
head(iris) # Views iris data## 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 setosaQ1: In your R Markdown file, run these functions for the iris dataset: summary(), str(), and head(). Present the results below. Briefly summarize what information each function tells you.
data(“iris”) #loads data
head(iris) #opens first 6 rows of data
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1 5.1 3.5 1.4 0.2
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
summary(iris) #summary of the data means, medians, quartiles
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
Min. :4.300 Min. :2.000 Min. :1.000 Min. :0.100 setosa :50
1st Qu.:5.100 1st Qu.:2.800 1st Qu.:1.600 1st Qu.:0.300 versicolor:50
Median :5.800 Median :3.000 Median :4.350 Median :1.300 virginica :50
Mean :5.843 Mean :3.057 Mean :3.758 Mean :1.199
3rd Qu.:6.400 3rd Qu.:3.300 3rd Qu.:5.100 3rd Qu.:1.800
Max. :7.900 Max. :4.400 Max. :6.900 Max. :2.500
str(iris) #data types and levels of categorical variables
‘data.frame’: 150 obs. of 5 variables:
$ Sepal.Length: num 5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 …
$ Sepal.Width : num 3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 …
$ Petal.Length: num 1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 …
$ Petal.Width : num 0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 …
$ Species : Factor w/ 3 levels “setosa”,“versicolor”,..: 1 1 1 1 1 1 1 1 1 1 …
Q2: In your R Markdown file, pick out the Species column in the iris dataset using all three methods discussed in the lab. Present your results below. Be sure to comment your code.
iris$Species #shows species in iris data
[1] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[11] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[21] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[31] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[41] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[51] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [61] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [71] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [81] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [91] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [101] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [111] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [121] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [131] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [141] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica Levels: setosa versicolor virginica
iris[,5] #use the column number
[1] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[11] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[21] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[31] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[41] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[51] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [61] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [71] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [81] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [91] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [101] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [111] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [121] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [131] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [141] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica Levels: setosa versicolor virginica
iris[, “Species”] #put the name of the column after the comma
[1] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[11] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[21] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[31] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[41] setosa setosa setosa setosa setosa setosa setosa setosa setosa setosa
[51] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [61] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [71] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [81] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [91] versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor versicolor [101] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [111] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [121] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [131] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica [141] virginica virginica virginica virginica virginica virginica virginica virginica virginica virginica Levels: setosa versicolor virginica
Q3: In your R Markdown file, write the code that would plot the Sepal.Length by the Species in the iris dataset. Be sure to get the independent and dependent variables on the correct axes! Comment your code appropriately. Present your results below.
plot(iris\(Sepal.Length ~ iris\)Species) #making a plot
Q4: In your R Markdown file, write the code that would plot the Petal.Length by Petal.Width in the iris dataset. Be sure to get the independent and dependent variables on the correct axes! Comment your code appropriately.
plot(iris$Petal.Length ~ iris$Petal.Width) #making a plot
Figure: WRITE CAPTION HERE.
Q5: Draw on your knowledge of ecology to justify your determination of which variables were independent and dependent for Q3 and Q4.
For Q3 the independent variable was species because its variation did not depend on anything else, so the dependent variable was Sepal Length because that was what was measured. For Q4 I didn’t think there was a specific indepedent or dependent variable, but by looking at the data I decided that as the width of the petal increases, so does its length.
Please turn–in your homework via Sakai by saving and submitting an R Markdown PDF or HTML file from R Pubs!