ElemStatLearn: Data Sets, Functions, and examples from The Elements of Statistical Learning, Data Mining, Inference, and Prediction by Trevor Hastie, Robert Tibshirani, and Jerome Friedman:
https://cran.r-project.org/web/packages/ElemStatLearn/index.html
http://statweb.stanford.edu/~tibs/ElemStatLearn/
reshape: Flexibly reshape data:
https://cran.r-project.org/web/packages/reshape/index.html
scatterplot3d: 3D Scatter plot:
https://cran.r-project.org/web/packages/scatterplot3d/index.html
NbClust: Determining the Best Number of Clusters in a Data Set:
https://cran.r-project.org/web/packages/NbClust/index.html
cluster: "Finding Groups in Data": Cluster Analysis Extended Rousseeuw et al:
https://cran.r-project.org/web/packages/cluster/index.html
HSAUR: A Handbook of Statistical Analyses Using R (1st Edition):
https://cran.r-project.org/web/packages/HSAUR/index.html
amap: Another Multidimensional Analysis Package:
https://cran.r-project.org/web/packages/amap/index.html
cba: Clustering for Business Analytics:
https://cran.r-project.org/web/packages/cba/index.html
rattle: Graphical User Interface for Data Mining in R:
https://cran.r-project.org/web/packages/rattle/index.html
fpc: Flexible Procedures for Clustering:
https://cran.r-project.org/web/packages/fpc/index.html
dendextend: Extending R's Dendrogram Functionality:
https://cran.r-project.org/web/packages/dendextend/index.html
corrplot: Visualization of a correlation matrix:
https://cran.r-project.org/web/packages/corrplot/index.html