inst/examples_output/iris.md

In djvanderlaan/tinymarkdown: Simple Engine for Generating Reports using R

title: An analysis of iris

Introduction

From the help page of the iris data set:

This famous (Fisher's or Anderson's) iris data set gives the measurements in centimeters of the variables sepal length and width and petal length and width, respectively, for 50 flowers from each of 3 species of iris. The species are Iris setosa, versicolor, and virginica.

Descriptives

The table below shows for each of the iris species the mean value of the colums in the data set.

: Mean values for each of the properties for each of the iris species.

|Species |Sepal.Length|Sepal.Width|Petal.Length|Petal.Width| |----------|------------|-----------|------------|-----------| |setosa |5.006 |3.428 |1.462 |0.246 | |versicolor|5.936 |2.770 |4.260 |1.326 | |virginica |6.588 |2.974 |5.552 |2.026 |

> pal <- hcl.colors(3, "Dark2")
> plot(iris$Sepal.Width, iris$Sepal.Length, pch = 20, 
+   col = pal[iris$Species], xlab = "Sepal Width", 
+   ylab = "Sepal Length", bty = 'n', las = 1)
> legend("topright", legend = levels(iris$Species), 
+   fill = pal, bty = 'n', border = NA)

{#figure}

Species prediction

> library(MASS)
> m <- lda(Species ~ Sepal.Width + Sepal.Length, data = iris)
> p <- predict(m)
> predicted_species <- p$class
> table(predicted_species, iris$Species)

predicted_species setosa versicolor virginica
       setosa         49          0         0
       versicolor      1         36        15
       virginica       0         14        35

This model predicts in 80% of the cases the correct species. However, this is mainly for setosa for the other species the model predicts the correct species only for 71% of the records.

djvanderlaan/tinymarkdown documentation built on March 19, 2023, 11:56 p.m.