Visualizing the isolation score

Introduction to Anomaly Detection in R

Alastair Rushworth

Data Scientist

Sequences of values

h_seq <- seq(min(furniture$Height), max(furniture$Height), length.out = 20)

w_seq <- seq(min(furniture$Width),  max(furniture$Width),  length.out = 20)

seq() arguments

from - upper bound
to - lower bound
length.out - values in the sequence

Building a grid

furniture_grid <- expand.grid(Width = w_seq, Height = h_seq)

head(furniture_grid)

     Width Height  
1 46.85100 44.359 
2 51.48663 44.359 
3 56.12225 44.359 
4 60.75788 44.359 
5 65.39351 44.359 
6 70.02913 44.359

Scoring the grid

furniture_grid$score <- predict(furniture_forest, furniture_grid)

Make the contour plot!

library(lattice)
contourplot(score ~ Height + Width, data = furniture_grid, 
            region = TRUE)

Let's practice!

Introduction to Anomaly Detection in R