Machine Learning with R Cookbook - Second Edition

How to do it...

Perform the following steps to perform nonlinear dimension reduction with ISOMAP:

1. First, install and load the RnavGraphImageData and vegan packages:

        > install.packages("RnavGraphImageData")
        > install.packages("vegan")
        > library(RnavGraphImageData)
        > library(vegan)  

2. You can then load the dataset, digits:

        > data(digits)  

3. Rotate and plot the image:

       > sample.digit = matrix(digits[,3000],ncol = 16, byrow=FALSE)
       > image(t(sample.digit)[,nrow(sample.digit):1])  

A sample image from the digits dataset

4. Next, you can randomly sample 300 digits from the population:

> set.seed(2) > digit.idx = sample(1:ncol(digits),size = 600) ...