Description
Clustering
You have been provided with the following 8 2-dimensional datasets for clustering: Aggregation, Compound, Path-based, Spiral, D31, R15, Jain, Flames. First two columns are the
features and the third column is the class label. In all your experiments, make sure that you
are not giving the third column also as input to the clustering algorithm. You need to turn
in the visualizations of your results for each question.
1. Convert all 8 datasets into ARFF format.
2. Visualize all 8 datasets. You need to turn in all your plots. Analyze each dataset
by visualization and explain how these clustering algorithms will perform on these
datasets (with reasons) : K-means, DBSCAN, hierarchical clustering with single link
and complete link.
3. Run K-means on R15 dataset. Set k = 8. Report the cluster purity. Vary the value of
k from 1 to 20 and study the effect of k on cluster purity. Plot a graph which explains
your study.
4. Run DBSCAN on Jain dataset. Again report cluster purity. Study the effect of
minpoints and epsilon on cluster purity.
5. Run DBSCAN and hierarchical clustering on Path-based, Spiral and Flames datasets.
Compare their performance on each dataset. For hierarchical clustering, you need to
experiment with all types of linkages available in Weka to find the one that best suits
the data.
6. Run K-means on D31 dataset. Can you recover all 31 clusters with k = 32? If not,
can you recover all clusters by increasing the value of k? What happens when you
run DBSCAN on the dataset? Run hierarchical clustering with Wards linkage on the
dataset. How does it perform?
Decision Trees
For this experiment, we will use Mushroom dataset from UCI machine learning repository
(https://archive.ics.uci.edu/ml/datasets/Mushroom). This is a 2-class problem with
8124 instances. Use the last 1124 instances as test data and the rest as training data.
1. Convert the data into ARFF format.
2. Run J48 Decision Tree algorithm from Weka. Report precision, recall and f1- measure.
What is the effect of M inNumObj on the performance? What happens when you do
reducedErrorP runing?
3. What are the important features in deciding whether a mushroom is edible or not?
4. Turn in the Decision Tree learnt by the model (the decision tree with the best performance).
Submission Instructions
Submit a single tarball file containing the following files in the specified directory structure.
Use the following naming convention: ‘cs5011 pa3 rollno.tar.gz’
data
spiral.arff
…
code
all your code files
report.pdf
decision tree model
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