Classification in the form of dendrograms can be done with following commands (only first 10 rows of dataset are used here to simplify the plot):

**Code:**

> fit = hclust(dist(bwdf[1:10,]))

> plot(fit)

**Output graph:**

It shows that rows named '0-1' an '0-2' are very similar to each other.

Following command which uses varclus (variable clustering) function of Hmisc package can be used to create dendrogram of different variables:

**Code:**

> library(MASS)

> data(birthwt)

> library(Hmisc)

> plot(varclus(as.matrix(birthwt)))

**Output graph:**

** **

It can be seen that low and bwt are related, as are age and ftv and also race and smoke.

References:

mass package: Venables, W. N. & Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth Edition. Springer, New York. ISBN 0-387-95457-0

https://cran.r-project.org/web/packages/MASS/index.html

Frank E Harrell Jr, with contributions from Charles Dupont and many others. (2015). Hmisc: Harrell Miscellaneous. R package version 3.16-0. http://CRAN.R-project.org/package=Hmisc