This code utilizes Python libraries (`pandas` and `numpy`) to perform...
This code utilizes Python libraries (pandas
and numpy
) to perform the initialization steps for a clustering algorithm, specifically setting up and assigning initial cluster labels for a variation of the k-means clustering algorithm. Below is an explanation of what the code does step-by-step:
Step-by-Step Breakdown:
-
Import Libraries:
pandas
is imported aspd
for handling data in tabular format (e.g.,.csv
files).numpy
is imported asnp
for mathematical operations and numerical computations.
-
Read Input Files:
- It reads three CSV files:
'article_histograms.csv'
(presumably containing numerical features, such as histograms).'article_titles.csv'
(likely containing article titles, but not used in the clustering computation).'dictionary.csv'
(unspecified use in the provided code, also unused in current processing).
- The data from the files is converted into NumPy arrays via
.to_numpy()
.
Key variable names:
histograms
: A 2D NumPy array with article data (dimensions of(N, M)
whereN
is the number of articles, andM
is the number of features per article).titles
,dictionary
: NumPy arrays (content not used in subsequent computations).
- It reads three CSV files:
-
Initialize Parameters:
- Number of clusters (
k
): The number of clusters to partition the data into is set to3
. - Random seed (
np.random.seed(43)
): Sets a seed for reproducibility of random numbers.
- Number of clusters (
-
Initialize Centroids (
z
):- Randomly generates
k
initial centroids (z
) for the clustering process. z
is a 2D NumPy array of shape(k, M)
. Each centroid corresponds to one cluster.- The centroids are initialized with random values (
np.random.rand
) scaled by the mean of thehistograms
array.
- Randomly generates
-
Assign Initial Cluster Labels (
c
):- Initializes an empty array
c
of sizeN
(same as the number of articles) to store which cluster each article belongs to. - The code iterates over all articles (
for i in range(histograms.shape[0])
).- For each article, it computes the Euclidean distance to each centroid (
np.linalg.norm(histograms[i] - z[j])
). - The cluster index (
j
) that has the smallest distance is assigned toc[i]
using.argmin()
.
- For each article, it computes the Euclidean distance to each centroid (
- Initializes an empty array
-
Print the Initial Cluster Assignments (
c
):- After the loop,
c
is printed. This is a 1D NumPy array of sizeN
where each entry indicates the index of the cluster to which the corresponding article is closest based on the initialized centroids (z
).
- After the loop,
Summary:
The code performs data import and initializes cluster centroids and assignments for what appears to be a k-means clustering algorithm. Specifically:
- The centroids are randomly initialized with values proportional to the histogram data.
- Each data point (
histogram
) is assigned to the nearest initial centroid based on Euclidean distance. - The resulting cluster assignments (
c
) are printed to the console.
This code does not implement the complete k-means clustering algorithm as it lacks iterations for updating centroids and reassigning clusters. Instead, it performs a one-time random initialization and assigns clusters based on these initial centroids.